Computer-Craft-1992-05.pdf - World Radio History

117

ci)C

Ni

irk taco0) 13C

AcoCco

coU

GREG SELF

9782 BRANCRiFT ROAD

PO BOX 274

BANCROFT

.MI 48414

Bulk R

ate

U.S

. Postage

PA

ID

Perm

it No. 79

Gordonsville, V

A

22942

hiqxWe'll hook you up-

Over 5000 products to choose from!HARD CARDS EX-HX HARD DRIVE SYSTEMSOur Hard Cards come preformatted, pre -tested, in Tandy/iBM computers. They include Ask management and disk cachespeed-up software. Also comes with many other free software programs such as games. utilities, and many others, TheseHard Cards are easy to install and can go from one machine to another. Install in minutes, just plug in and go! (Please speak/if you own a Tandy, IBM, or IBM Compatible)

Our Hard Drive systems have been preformafted and pretested in Tandy EX/HX computers. Disk management as well asspeed-up software programs such as games, utilities and many others! By simply removing the EX/HX adaptor our drives willplug into any normal computer. Order the flash drive today and spend hours with the free software!

OH EX -1 -IX Extenal Drives 21 Meg 39ms .............._..285.00 Internal 42 Meg 28ms 6298008 BIT. 16 BIT. OH EX -HO Extenal Drives 32 Meg 39ms ..................325.00 Internal 85 Meg 16ms.., $389.00

DH Lightcard 21 Meg 39 ms........ .....229.00 DH Lightcard 21 Meg 39 ms. .244.00 OH EX -HO Extenal Drives 42 Meg 28ms ..................375.00 Internal 105 Meg 19ms. $469.00DH Lightcard 32 Meg 39 ms 245.00. DH Lightcard 32 Meg 39 ms.. .26800. OH EX -HO Extenal Drives 50 Meg 28ms ..................455.00 Intemal 130 Meg 15ms. $49900DH Lightcard 42 Meg 38 ms 280.00. DH Lightcard 42 Meg 38 ms. 295.00. DH EX-HX Extenal Drives 68 Meg 22ms ..47900DH Lightcard 50 Meg 28 ms 329.00. DH Lightcard 50 Meg 28 ms. 08 E X -H X Extenal Drives 85 Meg 28ms 515.00DH Ughtcard 68 Meg 22 ms 375.00. DH Ughtcard 68 Meg 22 ms.DH Ughtcard 85 Meg 28ms........DH Lightcard 111 Meg 28ms......

425.00.685.00

DH Lightcard 85 Meg 28 ms.DH Lightcard 111 Meg 28ms

_499.00._699.00. FAX BOARDS

HARD DRIVES Comes complete with phone cord and software. Full Ave year warranty!Send FAX 4800 BAUD Int

Our Hard Drives are initlialiaed, partitioned and fonnafted. Each drive is then tested for integrity, to ensure you get a first classproduct! Included with your drive you get disk management as well as speed caching software. Also included are many otherprograms such as games. utilities and many others. You will have hours of enjoyment from your new hand drive and freesoftware!

Model Size Brand Speed Dimension Bare XT/Tandy 16 Blt KitST225 21M Seagate 48ms 5.25 183. 224. 234.ST125 21M Seagate 28ms 3.5 224. 255. 265.KL320 21M Kalok 39ms 3.5 144.ST238R 32M Seagate 40ms 5.2 193. 237. 257.ST138R 32M 28msSeagatea 3.5 226. 254. 278.KL330 32M 39ms 3.5 163. 225. 234.ST251 42M Seagate 28ms 5.25 245, 286. 295.ST151 42M Seagate 24ms 3.5 336. 367. 376.SN2040 42M Samsung 35ms 3.5 197. 257. 267.KL343 42M Kalok 28ms 3.5 234. N/A 254.CP3044 42M Conner 28ms 15 286. WA 315.WD2044 42M Western Digital lams 1.0 294. N/A 325.ST157R 48M Seagate 28ms 3.5 266. 316. 326.ST157A 48M Seagate 28ms 3.5 235. N/A 287.PT1357R 48M PTI 28ms 3.5 257. 314. 334.MK134A 613M Toshiba 22ms 3.5 307. 356. 375.ST1277R 62M Seagate 28ms 5.25 257. 304. 326.MC8085 esm Microscience 40ms 5.25 326. 387. 424.ST296N 85M Seagate 28ms 5.25 317. 356. 385.ST1096N 85M Seagate 28ms 3.5 394. 455. 486.MX7080A 80M Maxtor 19ms 1.0 384. N/A 397.ST1125N 111M Seagate 19ms 3.5 694. 724. 754.

VGA ENHANCEMENTReady for VGA Upgrade the Data Hut Way! Full replacement warranty,

VGA Combo 14,.28 DP, 640x 480, 256 K, 8 Bit .... .386.00VGA Combo II: 14,28 DP, 640 x 480, 512 K,16 Bit .... .42500VGA Combo 111: 14,.28 DP, 1024 x 768, 512 K, 16 Bit . 455.00VGA Combo IV: 14,.28 DP, 1024 x 768, 1024 K.16 Bit .515.00

EXPANDED MEMORY BOARDSThese boards work in Tandy and XTs and include LIM 3.2 8 Bit

Board with 0 K..Board with 256 K.Board with 512 KBoard with 1 MEGBoard with 1.5 MEGBoard with 2 MEGBoard with 4 MEG

.....139.00.175.00

21500235.00

MODEMSOur Modems are Hayes compatible. They come complete with communication software cable and everything you need tostan communicating in minutes!

2400 BAUD Internal with MCP Level 52400 BAUD External..2400/48100 MNP 7 BAUD Modem.

Send/Receive FAX. Plus Modem MOO BAUD FAX/4800 Modem 135 00

SPEED ENHANCEMENTSIncrease the speed of your computer by an overall 50% with this easy to install upgrade! Installs in five minutes.IBM XT or IBM XT Compatible.Tandy 1000, 1000A, 100SXTandy 1000SL, 1000SU2...Tandy 1000EX, 1000HX.PC Sprint Increases CLK SPD Tandy 1000, 1000A. IBM XT, IBM XT Compatible .

24.9524.9534.9529.9574.95

FLOPPY DRIVE FOR TANDYSThese floppy ddves will install in minutes. Add a high density drive to your computer for less money! High density includecontroller card, cables, everything you need to make you start running!360K Internal Drive Kit .67.007200 Internal Drive Kit 78001.2 Meg Internal Drive Kit... .139.001.44 Meg Internal Nye Kit. .14500

SYSTEM MEMORY UPGRADESD 5X Upgrade Tandy EX or HX 10640............................DH 10X Upgrade Tandy SX, EX or HX from 384 to 640.DH 20L Upgrade SL or SL2 horn 38410540..................DH 3TX Upgrade any TX from 64010 768....DH 47L Upgrade TL or TI./2, TIJI from 640 to 768.......DH 561 Upgrade 3000 NL to 640.....__...._......_...........DH 6RL Upgrade Tandy 1000121, 1000RLX from 640 to 1 Meg.DH 100 Upgrade Tandy 1000 or 1000A from 12810640...........

120 Upgrade Tandy 1200 from 256 to 640DH IBM Upgrade IBM PC/XT ERP 256 to 640..

....,174.00

39.0042.95

200.00

Don't go nuts trying to install your hard drive.Flashdrive Parallel AC Only Hard DriveThe Flashdrive Parallel Hard Drives offer an easy way foryou to add a hard drive through the parallel port to anylaptop, notebook, PC/AT Desktop and PS/2 Computer.So compact and portable, you will take the ilashdriyeanywhere the laptop goes. Best of all is the low low priceof this top seller!Measures: 9.5L X 6" X 2.51-1 23 MS Access

Flashdrive Parallel Battery/AC Power Hard DriveThe flashdrive battery version includes Nicad Batterieswith an average of 4-6 hours of battery time, in a packagethat weighs only a pound and a half. Measures 5"W X5.25L X 1.5"H.Total Package 150KB transfer rate 19MSaccess time.

Comes in 20, 40, 60, 80, 120, 204, or 340MB. Accesstimes vary from 15MS to 23MS.Call for currant ;Hieing!

We won't be undersold! We'll beat any competitor's advertised price!

#6 North Ct. St.Owingsville, KY 40360M -SAT 9AM - 8PM ESTFAX 606-674-3917Local 606-674-3916

l 800 487.3488riz 1 C D

No Surcharge On Credit Cards C.O.D. & Purchase

Orders Accepted All Pricing & Availability

Subject to Change Without Notice

85

UPGRADING &ENHANCING

16 Removable Mass -Storage SCSICartridge DrivesBy Tom CarltonRelieves the perennial problem ofrunning out of hard -disk space.

20 Memory Management, Part 1By Wayne YaccoFit large programs into RAM from0 to 640K by moving as manyresources as possible into highmemory beyond 1M.

32 A Tower of an Enclosure,Part 4By Nick GossConstruction, checking out theCyance Bus Expander Systemand final installation.

APPLICATIONS

43 Adding Mouse Support toYour ProgramsBy Hardin BrothersMaking programs respond tomouse commands can bedeceptively simple.

46 Detecting & MeasuringPhysical ParametersBy Jan AxelsonHow to use sensors to detect andmeasure just about anything.

66

53 Windows & OS/2 ConferenceBy Tom CarltonA glimpse at what's churning forthe corporate world.

56 ExperimentingMotorola's 68HC11 TrueSingle -Chip Microcomputer,Part 5By Tom FoxUsing the BUFFALO Monitorand MAG-11 to produce aninexpensive single -chipMC68HCI I system.

66 VGA to the Max, Part 1By Crady VonPawlakA look at inexpensive near -TrueColor graphics and Windowsaccelerators.

REVIEWS70 PC -Generated Printed -Circuit

BoardsBy Tom FoxExperiences With "PCBoards"Software.

85 Computer GamesBy SF SparrowThe Upgrade Wars.

COLUMNS72 GUI Guts

By Wayne YaccoFitting More Power IntoWindows.

Volume 2, No. 5 May 1992

eter acme kesidence Aspen Colorado

75 Ted NeedlemanThe Software Toolworks "MiraclePiano Teaching System."

78 Joseph DespositoNew Neuron Chip; Multiple ArrayMatrix EPLD; New NECMicrocontrollers; and DualRS -232C IC.

DEPARTMENTS

4 EditorialBy Art SalsbergReader Profile.

6 What's Happening!Latest PC News.

7 Letters

8 What's New!By Peter R. O'DellA roundup of new computerand electronic products.

89 Advertisers Index

ON THE COVER: Removablemass -storage SCSI cartridge drives caneliminate the problem of constantly run-ning out of hard -disk space for storing ap-plications and files. They also provide aconvenient means for transporting filesfrom one computer to another and forsafeguarding data by storing the cartridgesin a locked safe.

Say You Saw It In ComputerCraft May 1992 / COMPUTERCRAFT / 3

Editorial

Reader Profile

Our recent readership study was very revealing.It indicated that you are indeed a special com-puter -involved audience.

Not surprisingly, some 87% of the respon-dents observed that they upgraded a computerthemselves (installing a hard drive, adding amemory board, etc.). The same percentage ownat least one PC, while most of the small remain-der own other microcomputer types, such asAmiga or Macintosh. What's more, two out offive respondents own a PC with a 386SX-or-bet-ter microprocessor, although half of you stillhave an AT (80286 -CPU) model. However,some of the latter are had by multiple PCowners, who number about one-third of re-spondents.

Less than 4% of you personally own a 486 -CPU computer, though a number of respon-dents use one in the work place. Interestingly,a StoreBoard/Computer Intelligence study in-dicates that about 3% of all PCs sold in 1991were 486 types (386DX and SX machines ledwith about 58). As I expressed in my March ed-itorial, I feel that the 486 is the way to go if you'replanning to buy a new system, even if it's onlya 486SX. Just be sure that your motherboardhas a processor enhancement socket (Intel ispressing board makers to include one in theirnew board designs).

I know that when one lays out personal ratherthan corporate money, there's a tendency to staysafely behind the leading technical edge in orderto reduce your outlay. For sound investmentreasons, though, I'd advise you to weigh optionscarefully because the 50 -MHz and faster486DXs are coming up, not to mention the 586microprocessor. With a 386, you won't easilybe able to play catch-up without dumping cost-ly entire boards. Although prices of 486DX25 -MHz computers have dropped dramatical-ly, I'd hold out for a 33 -MHz one.

Nearly one -fifth of PC owners who filled outour reader survey questionnaire already havenon -impact printers (laser or ink -jet), whileabout one-third own a 24 -pin model. I expectmore and more of you will choose to own theformer since selling prices have dropped con-siderably. Trading off speed for better outputquality and lower operating noise will win theday, I believe.

VGA or SVGA video monitors dominateamong our readers, with about 70% of you in-dicating you have one. It's obvious from com-puter system types cited on the survey that manyof you upgraded your systems to this higherstandard.

Given the technical orientation of Computer -Craft, it's natural that many readers carry atechnical title in either the computer or elec-tronics industry. Indeed, the study reveals thatmore than half do-engineers, technicians, pro-grammers, LAN administrators, system devel-opers, etc. Corporate executives, business own-ers, educators and students account for anotherquarter. And nearly 15% are computer resellers,professionals (physicians, accountants, etc.) orcraftsmen (mostly plant electricians). The re-mainder bear such titles as CAD draftsmen,computer sales/service representative, technical

writer, computer operator, armed forces, anda wide variety of others.

The median age of respondents is estimatedto be in the late thirties, the largest group beingbetween 35 and 44 years.

Clearly, the core of ComputerCraft readersis unlike that of most computer publications.The study substantiated that they're active com-puter users who open the cases of their equip-ment to improve or expand its operation andwho constantly seek new ways to apply their PCsand microcontrollers at work and at home. Howclosely do you fit into the average reader pro-file outlined here?

In the software world, word-processing pro-grams are used by most respondents, which isnatural. But other applications are heavily used,too. More than half of you also employ telecom-munications, database, spreadsheet and graph-ics packages, while computer -aided design(CAD) and Microsoft Windows are used by 41%and 40% of respondents, respectively. Desktoppublishing, too, has a strong user base amongour readers, with almost one-third of respon-dents using the software.

Most respondents said they are involved withcomputer languages, led by BASIC with near-ly three-quarters. This is followed by assemblylanguage with 45%, QuickBASIC with 37%, Cwith 35%, Turbo Pascal with 20% and C + +with about 15% of readers who do programming.

About three -fourths of respondents who usetelecommunications software also subscribe toan on-line service, led by CompuServe with39%. Prodigy follows with 30% and GEnie with18%, Farther down are America Online with12% and Delphi with 8%.

As we already know, the microcontroller fieldis increasingly popular among our readers. Ap-proximately three out of five respondents indi-cate they use or plan to use a microcontrolleror SBC, while nearly this number say the samefor an EPROM programmer or emulator. Some33% of you use test products, software or hard-ware, to repair computers. About 33% reportedthey were involved in computer networking.

Mail-order purchases represent the largestbuying source, with three out of five respondentsindicating this for hardware and a nearly equalnumber for software. About 15% noted theyalso purchase products from computer showsand swap meets. Extrapolating the study's re-sults on computer buying plans for the next 12months, the average reader is expected to spend$2,694 on hardware and software.

ComputerCraft readers are heavily involvedwith computers at their work, with better thantwo out of five in the study indicating they'reemployed in the computer or a related field. Asimilar number note that they are responsiblefor selecting computer equipment at their work -site, while another one-third report that they dothis informally.

EDITORIAL STAFFArt Salsberg

Editor -in -Chief

Alexander W. BurawaManaging Editor

Dorothy KehrwiederProduction Manager

Emily KreutzProduction

Elizabeth RyanArt Director

Barbara TerzoAssistant Art Director

Susan RealeArtist

Pat Le BlancFlorence V. MartinLinda RomanelloPhototypographers

Hal KeithIllustrator

Bruce MorganPhotographer

Bud Aaron, Jan Axelson, Tom Benford,Hardin Brothers, TJ Byers, Joe Desposito,Nick Goss, Martin Meyer, Ted Needleman,

Peter R. O'Dell, SF Sparrow, Stan VeitContributing Editors

BUSINESS STAFFRichard A. Ross

Publisher

Art SalsbergAssociate Publisher

Dorothy KehrwiederGeneral Manager

Frank V. FuziaController

Catherine RossCirculation Director

Melissa KehrwiederCarol Minervini

Data Processing

Denise PyneCustomer Service

ADVERTISING SALESEric Teitelbaum

Margaret Milanese

(516) 681-2922FAX: (516) 681-2926

Karen NauthSales Assistant

Offices: 76 North Broadway, Hicksville, NY 11801. Tele-phone: (516) 681-2922. FAX (516) 681-2926. Computer -Craft (ISSN 1055-5072) is published monthly by CQCommunications, Inc. Subscription prices (payable inUS Dollars only): Domestic-one year $18.97, two years536.00, three years $53.00; Canada/Mexico-one year$21.00, two years $40.00, three years 859.00; Foreign-one year $23.00, two years $44.00, three years $65.00.Foreign Air Mail-one year $76.00, two years $150.00,three years $224.00.

U.S. Government Agencies: Subscriptions to Computer -Craft are available to agencies of the United States gov-ernment, including military services, only on a cash withorder basis. Requests for quotations, bids, contracts, etc.will be refused and will not be returned or processed.

Entire contents copyright 1992 by CQ Communications,Inc. ComputerCraft or CQ Communications Inc. as-sumes no responsibility for unsolicited manuscripts. Al-low six weeks for delivery of first issue and for change ofaddress. Printed in the United States of America.

Postmaster: Please send change of address notice toComputerCraft, 76 North Broadway, Hicksville, NY11801.

4 / COMPUTERCRAFT / May 1992 Say You Saw It In ComputerCraft

B. C. MICROSPECIAL S SUPER BUYS

MAX232 2.301488 451489 45DB25-(Solder Cup) M/F 2/1 00DB25-Rt. Angle PC BD. F 55

DTMFSSI-202 Decoder 2.258870 Decoder 2.255087 Generator 2.005089 Generator 2.10

DB9-Rt. Angle PC BD. M/F .35

FANS THE 525 NETWORK

12VDC - BrushlessManufactured by Commonwealth

Model FP 108D-7 Blades8" Wire Leads - 150MA31/4" Square - 1" Thick

This size commonly used incomputer power supplies.

56.95 ea.

Try The 1st Truly Low Cost LAN Connect 2 or 3 PCs, XTs, ATs Uses serial ports and 5 wire

cable Runs at 115 K baud Runs In background, totally

transparent Share any device, any file, any

DISPLAY DEVICEStime

Needs only 14K of ramWe believers!

FLAT PANEL LCDIGRAPHIC DISPLAYEPSON EG-7004S-AR

MO a 200 dots - Super MistedBuilt In drivers 4 bit TTL Interface

displaying numerics, graphics, alphebelics,cheracters, graphs, charts,

Viewing eras 16-7/16"x 44/11".0verall113/8"14 pins for signets and power

Complete 27 page men.'

II

Skeptical: make

LITTLE BIG LANnemetic type.

- Capable atspecial

end patterns.x 6-1/16"

(.3V, -12V).

Low cost - 575 par LAN, not per node,Hardware Independent network

ARCNET, Pantile!. and Serial portsupport on first releaseSerial Speed: 6500(XT)-8500(AT) bytesper secondParallel Speed: 6000(XT)-29000(AT) byte.per second

$19.95 6/5100.00 ARCNET Speed: 40000 plus bytes persecond

OLc)

LTP 1157AE1.2" 5x7 Matrix Displays

507 Array with x.y select.

Use any PC/XT/AT/386 mix, even laptop.and PS/2 machine.

Connect up to 254 computers. can mixconnection methods (Serial. Parallel,

This Red Orange Matrix Can Be Arcnel)

ccStacked Horizontally. Choice ofTwo Matrix Orientation -Cathode

DOS File and Record locking supportShare any device, any the, any programRuns in the background, totally transparent

Column, Anode Row. Great For Low memory overhead"Moving Message" Signs. Typically only 285 is needed, but will

O$1.19 Ea , 8/$6.95, 100/$75.00 vary with various setups

Including DBASE

74LSWorks with most software.III, Microsoft

WORD, LOTUS 123, Windows 3,AUTOCAD. Word Perfect, all compliers.

LSOO .14 LS114 .25 LS241 .60 GWBASIC. and, in tact, most anything,

LSO1 .14 LS122 .35 LS242 .65 Works with DOS 2.0 to DOS 5.0 and DR.

LSO2 .14 LS123 .45 LS243 .50DOS

DOS 3.1 or greater Is preferredLSO3 .14 LS1241.35 L$244 .55 Open network, programmer API provided

%cLSO4 .14 LS125 .30 LS245 .55LSO5 .14 LS126 .35 LS251 .45

Example for low-level link modules -you can support special hardwareFull specs provided on packet level

LSO8 .14 LS132 .35 LS253 .40 protocols

LSO9 .14 LS133 .25 LS257 .35 CABLES & ARCNET CARDSAVAILABLE - PLEASE CALL $75.

LS10 .14 LS136 .28 LS258 .45SOCKETSLS11 .14 LS138 .35 LS2591.00

LS12 .20 LS139 LS260 .40 Low Profile SOLDER TAIL.35LS13 .25 LS145 .75 LS266 .30LS14 .30 LS148 .35 LS273 .75 6 Pin 14/1.00

cc14.

LS15 .20 LS151 .35 LS279 .30LS20 .14 LS153 .35 LS280 .80LS21 .16 LS154 .85 LS283 .35

8 Pin 13/1.0014 Pin 13/1.0016 Pin 13/1.00

ccLS22 .16 LS155 .50 LS290 .70LS26 .14 L$156 .42 LS293 .50

18 Pin 13/1.0020 Pin 13/1.00

LS27 .20 LS157 .30 LS298 .65 22 Pin 13/1.00LS28 .15 LS158 .25 LS299 1.00 24 Pin 8/1.00LS30 .14 LS160 .25 LS3221.30 28 Pin 7/1.00LS32 .16 LS161 .35 LS3232.25 40 Pin 7/1.00LS33 .25 LS162 .45 LS348 .75 BUY $10LS37 .24 LS163 .36 LS3531.00 GET $1.00 - FREE CHOICELS38 .24 LS164 .45 LS357 .80 68 Pin PLCC .79LS42 .35 LS165 .60 LS363 .75 84 Pin PLCC .89LS51 .15 L$166 .75 LS364 .75LS54 .20 LS169 .90 LS365 .30 6500/6800LS55 .20 LS170 .45 LS366 .28

6502 2.00 6821 1.00LS73 .33 LS173 .60 LS367 .35LS74 .22 L$174 .35 LS368 .30 6520 1.25 6845P 2.20LS75 .25 LS175 .35 LS373 .50 6522 2.70 6845S 2.20LS83 .30 LS181 1.25 LS374 .45 6530 3.00 6850 1.75LS85 .45 LS191 .45 LS375 .35 6532 4.25 6852 3.50LS86 .20 LS192 .65 LS377 .75 6545 2.10 6860 3.95LS90 .35 LS193 .65 LS378 .80 6551 2.40 68681 3.00LS92 .30 LS194 .40 LS390 .80 6800 1.40 68A09EP 1.29LS93 .25 LS195 .52 LS393 .75 6802 2.50 68A40 4.00LS95 .30 LS196 .55 LS3991.00 6803 3.00 68A54 3.00LS96 .33 LS197 .75 LS541 1.20 6805 2.95 68B09 4.00LS107 .28 LS221 .50 LS645 .75 6809EP 2.75 68B10 2.00LS109 .20 LS240 .50 LS646 .75 6809P 2.50 69B45 4.95LS112 .25 LS670 .80 6810 1.25 68B54 4.00LS113 .25 25LS2569 1.50

P. 0. Box 280298 Dallas, Texas 75228(214) 271-5546FAX (214) 271-2462

MosterCord VISA

TEXT TO SPEECH BOARD

PC/XT COMPATIBLE. MAKE YOUR COMPUTER TALK!

$ 69 954°CSCASSEMBLED & TESTED

ADD $3.50 SHIPPING8 HANDLING

A VERY POWERFUL AND AMAZING SPEECH CARD. USES THEGENERAL INSTRUMENTS SP0256-AL2 SPEECH CHIP AND THECTS256A-AL2 TEXT TO SPEECH CONVERTER.THIS BOARD USES ONE SLOT ON THE MOTHERBOARD ANDREQUIRES A COM SERIAL PORT. BOARD MAY ALSO BE USED IN ASTAND ALONE ENVIRONMENT (EXTERNAL POWER SUPPLY) WITHALMOST ANY COMPUTER THAT HAS A RS232 SERIAL PORT. TOUSE THE BOARD IT IS ONLY NECESSARY TO SEND ENGLISH TEXTTO THE RS232 INPUT ON THE BOARD. THE BOARD INCLUDES A1500 BYTE TEXT BUFFER AND HANDSHAKE LINE TO ALLOW YOUTO SEND DATA TO THE BOARD; THE SAME AS YOU WOULD SENDDATA TO AN RS232 SERIAL PRINTER. YOU CAN SET UP BATCHFILES THAT WILL MAKE YOUR COMPUTER GREET YOU WITH"GOOD MORNING MASTER," ETC. EVERY TIME YOU TURN IT ON.DEMONSTRATION SOFTWARE AND A LIBRARY BUILDING PRO-GRAM ARE INCLUDED ON A 51/4 INCH PC/XT DISKETTE. FULLDOCUMENTATION AND SCHEMATICS ARE ALSO INCLUDED.FOR INFORMATION ON A LOW COST SPEECH SYNTHESIZERSYSTEM FOR THE VISUALLY IMPAIRED, PLEASE SEND FOR FREEPACKET T.M.1.

STAND ALONE POWER SUPPLYFORA BOVE $19 99ADD $2.50 SHIPPING 8 HANDLING

STATIC RAM EPROM SPECIAL2016-2KX8 200 n.s. 1.002101-1 - 256X4 500 n.s. .7521L02-1 350 n.s. .652102AL-4 L.P. 450 n.s. .492111-1 256X4 500 n.s. .. 1.002112A-2 2.502114L-3 1KX4 300 n.s. .452125A-2 1KX1 70 n.s. 1.702147 4KX1 1.956116P-461176264-1562256 32K X8

1.001.201.405.75

DYNAMIC RAM2108-4 8K X1 1.502118-4 16KX1-5Volt .704027-4KX1-250 n.s. .804116-16KX1-250 n.s. .404116-16KX1-200 n.s. 754116 16KX1-150 n.s. .904164 150 n.s. ... .49 or 9/3.504164 120 n.s. 1.104164-100 n.s 1 40TMS4416-16KX4-150 n.s. 2.754464-150 n.s 1 404464-120 n.s 1.454464-100 n.s 1.454464-80 n.s. 1.4541256 150 n.s. . 1.25 or 9/9.9541256 120 n.s. 1.30 or 9/10.9941256 100 n.s. 1.30 or 9/10.9941256-80 n.s. 1.30 or 9/10.99

1.854.404.404.60

41256-60 n.s1 Meg - 100 n.s.1 Meg - 80 n.s.414256-80 n.s. 256 x 4SIPPS & SIMMS AVAILABLE

THREE CHIP SETB.G. SPECIAL

16450, 1488, 1489 - $6.9516550, 1488, 1489 - $13.50

We bought a large quantity of2708s, 2716$, 2532s, 2732s,2764s, 27128s, 27256s and27512sfrom a computer manu-facturer who redesigned theirboards. We removed them fromsockets, erased and verifiedthem, and now we offer the sav-ings to you. Complete satisfac-tion guaranteed.

Your Choice1.20 10/8.001.75 10/15.002.00 10/17.502.00 10/17.502.00 10/17.503.00 10/25.003.50 10/30.004.75 10/40.00

27082716253227322764271282725627512

8000/800008031 2.9580C32 12 3.958035 1.008039 1.008085 1.558086 1.558087 87.508087-1 167.508087-2 127.508088 2.208088-2 3.258155 2.258156 2.258202A 8.008212 1.258214 2.00

8251 1.108253-5 1.758254 1.808255 1.508255-5 1.758257 1.508259A 1.858259C-5 2.108275 10.958279 2.258284 1.496286 3.508287 2.498288 3.508530 3.008741 7.00

8216 1.25 8742 7.008224 1.25 8748 7.008228 1.75 8749 7.008237-5 2.80 8755 7.008243 1.75 80286-8 PLCC 8.508250 2.95 80287-8 125.00(16450) 6.50 80287-10 135.00(16550) 13.00 V-20-10MHZ 6.50

TERMS: (Unless specified elsewhere) Add $3.25 postage, we pay balance. Orders over $50.00 add 85C for insurance. No C.O.D. Texas Res. addTax. 90 Day Money Back Guarantee on all items. All items subject to prior sale. Prices subject to change without notice. Foreign order - US funds

only. We cannot ship to Mexico or Puerto Rico. Countries other than Canada, add $9.00 shipping and handling.

rn

C)

-n

rnrn

r -C)

O

c -nO

rri

-1rri

CIRCLE NO. 54 ON FREE INFORMATION CARD

What's Happening!

Michelangelo Virus Spreading. Discovered in mid -1991, theMichelangelo virus is said to have infected many products. Amongthem are Leading Edge Products, which shipped 6000 infectedmachines, and 600 demo disks from DaVinci Systems. The virus usesthe same efficient replication process found in the Stoned virus,the most common one in the U.S. It presents no warning untiltriggered on March 6 of any year, when it overwrites the harddisk with random information found in memory. It infects masterboot records of hard disks and boot sectors of floppy disks.

According to the National Computer Security Association, thevirus occupies about 2K of memory when resident, decreasing whatDOS reports as available memory by that amount. When resident inmemory, any action that accesses a floppy disk via interrupt 13hwill infect the disk. Some reports indicate that the virusmisinterprets a 1.44M floppy's Disk Parameter Block, returning amessage, "Invalid Media," when accessed again.

The virus is said to be easy to remove. Call NCSA at717-258-1816 for free help in removing it and any other virus.

Multimedia Messaging. A software add-on developed by BellcoreLabs enables Internet users to send and receive high -qualitypictures and sound bites. Called Metamail, it's being given freeby Bellcore to subscribers to Internet, the information networkwidely used around the world by universities, nationallaboratories, and the like. Metamail is the first program to berun under a new proposed multimedia e-mail standard called MIME.The interactive program can be adapted to any computer that usesthe UNIX operating system. Since pictures and sound take muchmore time on phone lines that text data, the system is presentlyefficient only for users of high-speed phone links, not therelatively slow modems employed with most PCs.

Jobs. The employment situation in the electronics industryremains steady, says Management Recruiters, Cleveland, OHsearch/recruitment specialists. Based on its 28th poll, nearly80% of executives contacted said they either plan to increase ormaintain their staff levels....According to Department of Labornumbers reported last September, however, the industry had lost90,000 jobs. Only programming/software employment exhibited anincrease, +8.9%, while total employment in other computer andelectronics areas dropped 6.3%....JOBHUNT software by ScopeInternational (704-535-0614; orders only, 1-800-843-5627) canassist job -seekers in a work search. It provides names,addresses, phone/fax numbers and brief company profiles ofleading potential employers nationwide. It features search anddisplay by region and/or job function in computer science,engineering and other fields. You can type a sample cover letterfor a resume into the program's word processor and automaticallymail -merge it with addresses you selected. It also prints mailingand return -address labels. JOBHUNT, for IBM/compatible computers,uses 256K RAM and comes with both 5-1/4" and 3-1/2" disks. $49.95includes one free update.


Letters

Regarding CAD/CAM EmploymentI read your piece on CAD/CAM Em-

ployment in the "What's Happening!"section (January) and am interested in theNational Association of CAD -CAM Oper-ators. Could you provide me with the mail-ing address for this organization?

Ed FranciscoSalem, VA

NACO is located at 10801 Hammerly, Ste.216, Houston, TX 77043; tel.: 713-93 2-8 4 73 .-Ed.

Work of Fiction This is to advise you that Lexmark [anIBM Alliance company] has withdrawn aradio ad that referred to a fictional "Nee-dleman Report." We apologized to TedNeedleman for any misconceptions by lis-teners that the ad may have been referringto him personally. In no way was this theintended effect of the ad.

S. Brent BeckwithManager

Printer Market DevelopmentLexmark International, Inc.

Lexington, KY

Article Updates In "Experimenting With the Z8" (De-cember 1991), the pinout for the 2KEEPROM/EPROM/RAM/NVRAM isincorrect. The correct pins and signalnames are: pin 9 I/01; pin 10, 1/02; pin11, 1/03; pin 13, I/04; pin 14, 1/05; pin15, 1/06; pin 16, I/07 and pin 17, I/08.

Jan Axelson In "Add Write -Protect Switches to PCFloppy Drives (March), the sentence in lineseven, column three on page 50 shouldread: "Connect the + lead of your ohm-meter to the + 5 -volt red wire in the powercable and the other lead to terminal Z ofswitch Sa."

A.A. Mangieri The source (Magicland-see address be-low) for a ready -to -wire pc board for theMAG-11 SBC wasn't given in the Marchissue of ComputerCraft. Readers can ob-tain the following from this source: dou-ble -sided pc board, No. MAG-11BDb,with plated -through holes (includes PartsList, schematic and wiring and construc-tion guides) for $25; partial kit, No.MAG-11PKT/b, consisting of pc board,all ICs that aren't optional (includingchoice of MAG-11DIAG or BUFFALOfirmware in EPROM), 7.32K resistor, ICsockets, PC -compatible program disk(31/2 -inch or 5'/ -inch diskette and docu-mentation in three-ring binder for $65. For

other MAG-11-related parts and kits,please write for details.

I also discovered an error in the pc guidefor the MAG-11 in the March issue. It con-cerns the ground pin of J6, which is shownincorrectly connected to pin 20 of U/.There are several ways to fix this. (1) Leaveposition 4 of S2 set to ON to ground theappropriate pins of J6, but bear inmind that doing this prevents the AN/D4 from being used for A/D conversion.

(2) Cut the component -side trace from pin19 of J6 on the component side of theboard and jumper from pin 20 of J6 to thenearest ground. (3) On a single -sidedboard, simply move the jumper from itspresent position to ground. (4) modify thepc artwork in Fig. 7.

Tom FoxMagicland

4380 S. Gordon Ave.Fremont, MI 49412

Electronics Workbench®The electronics lab in a computer -Powerful software to buildand simulate analog anddigital circuits.

Building and testing circuits is fast andeasy with Electronics Workbench. Justclick -and -drag with a mouse to add parts,run wires, and adjust instruments. Thetraces on the simulated instruments arethe same as you'd get on real equipment.

Electronics Workbench really is anelectronics lab in a computer. It's idealfor learning about electronics,experimenting, and prototyping circuits.

"Electronics Workbench is prettyamazing." - ferry Pournelk, Ph.D., InfoWorld

DOS Professional Version - $299Macintosh Version - $199Electronics Workbench includes: Analog Module with passive and active

components including transistors, diodes,and op -amps; a function generator, anoscilloscope, a multimeter, and a Bodeplotter.

Digital Module with gates, flip-flops,adders, a word generator, a logic analyzer,and a unique logic converter and simplifier.

(416) 361-0333Interactive Image Technologies Ltd.908 Niagara Falls BoulevardNorth Tonawanda, NY14120-2060Fax (416) 368-5799

INTERACTIVEPrices are in US dollars. Offer valid in the USA and Canada only.Macintosh Version is monochrome only. All trademarks are theproperty of their respective owners.

CIRCLE NO. 73 ON FREE INFORMATION CARD7

What's New! By Peter R. O'Dell

No -Slot Hard DriveThe Backpack hard -disk driveis the latest addition to theBackpack line of no -slot peri-pherals from Micro Solutions.The drive is easy to install. Youjust plug it into the parallel portand run the automatic installa-tion program. It requires no in-terface card because data trans-fers go through the printerport. The drive has a printerport to enable a printer or an-other backpack to be attached.The Backpack hard driveworks on all DOS versions 3.0and later and isn't limited to32M partitions under DOS 3.0.Two models are available: 40Mat $625 and 100M at $795. Mi-cro Solutions, 132 W. LincolnHwy., DeKalb, IL 60115; tel.:815-756-3411; fax, 815-756-2928.

CIRCLE NO. ION FREE CARD

New Radio Shack ComputerThe Tandy 2500 SX/25 HD,the latest offering from RadioShack, features a 25 -MHz386SX with 2M of RAM (ex-pandable to 16M), one 3%"drive, an 85M "Smartdrive"hard disk, on -board SVGAwith 256K (expandable to512K), eight -bit bi-directionalsound circuitry, MS-DOS 5.0,Windows 3.0, three 16 -bit ISAslots, mouse and keyboard.Built-in ports include serial,parallel, mouse, microphoneand headphones. The 25005X/25 also features automatic soft-ware upgrade for any new ver-sion of Windows released be-fore June 30. There's also one

5V," open bay in the low -profile15%" x 15" x 414" case. Otherversions are available as specialorder items from Radio Shack.$1,300. Radio Shack, 700 OneTandy Center, Fort Worth,Texas 76102.

CIRCLE NO. 3 ON FREE CARD

New SimCheckAdaptersAristo Computers has a seriesof new adapters for the Sim -Check Memory tester. They'refor ZIP Memory chips, PLCCand SOJ memory chips, banks

of up to nine individual DRAMchips and Apple MacintoshIlfx SIMMs. SimCheck tests allstandard SIMMs and SIPs witheight or nine bits of 64K, 256K,1M, 4M, or 16M. A two-lineLCD display provides instruc-tions and test results. Defectivemodules are analyzed to pro-vide explicit fault indications,including identification of de-fective bits and open/short wir-ing problems. $995; adapters,$99 to $345. Aristo ComputersInc., 6700 SW 105 Ave., Bea-verton, OR 97005; tel.: 503-626-6333.


Fast SX CoprocessorHT has a new 33 -MHz mathcoprocessor for fast 386SX-based computers. The IIT-3C87SX is targeted at high-per-formance portable computersand the growing 386SX desk-top market. To serve the port-able market, IIT offers the3C87 coprocessors in space -saving PQFP packages. Likeall its current products, the33 -MHz IIT-3C87SX carries alifetime warranty and is guar-anteed to provide 100% com-patibility with 386SX systems

and software. $199. HT, 2445Mission College Blvd., SantaClara, CA 95054; tel.: 408-727-1885; fax, 408-980-0432.


Phone -UsageMonitor

CALLCOST from CMP auto-matically tracks incoming andoutgoing phone calls for pro-fessionals and small business-es. The CALLCOST packagecomes with a small hardwarebuffer box, software for a DOScomputer, documentation andnecessary cabling. Once con-nected, it stores informationabout phone activity on the linesuch as on-hook/off-hook sta-tus, numbers dialed, call dura-tion and time/date of the call.The buffer box tracks andstores all phone activity whe-ther the computer is on or not.Periodically, information inthe buffer box can be easily up-loaded to a PC using theCALLCOST software pro-gram. Phone data can be print-ed in a variety of report for-mats, to be used for client bill-ing, corporate reimbursementor general business manage-ment. CALLCOST has a facili-ty to set up a client databaseand account codes. Each pack-age monitors activity on one ortwo phone lines. $289. CMPInc., 2150 W. 6 Ave., Unit N,Broomfield, CO 80020. tel.:800-245-9933.


Word For WindowsMicrosoft Word For Windows2.0 focuses new features onmaking every,day word-pro-cessing tasks easier. The com-pany made extensive use of its"Usability Lab" to identifytasks most often used and thenminimized the effort to activatethem. Most needed features arenow found on the customizableToolbar. Cut -and -paste is re-placed with a "drag -and -drop" feature that greatly fa-cilitates editing text. An auto-matic envelope generator liftsthe address from a letter andplaces it in the proper positionon an envelope.

Microsoft created a new vis-ual Print Merge Helper thatguides the user through themail -merge process. You can

select bullets from a palette ofmore than 100, including stan-dard business bullets and morespecialized symbols like heartsand arrows. WFW 2.0 comeswith a new fully integratedgrammar checker based onHoughton Mifflin technology.A new graphical File Finder letsyou see long file names, thesubject or content of a docu-ment before opening it.

WFW 2.0 simplifies the pro-cess of creating and manipulat-ing tables. WordArt lets youmanipulate text and fonts cre-ate special effects such ascurved, rotated and even up-side-down text. Columns canbe activated instantly with amouse. You can choose froma wide variety of borders and


shading and present data in 3Dcharts, using the same chartingcapabilities as those of Micro-soft Excel. A new drawing fea-ture lets you create and en-hance visuals for a document.A special on-line help facility isavailable for users who are fa-miliar with WordPerfect 5.1.

WFW2.0 requires Windows3.0 or later, 286/386/486 basedcomputer, 2M of RAM, EGAor greater -resolution monitorand 5M of hard -disk space forthe minimum installation(maximum installation re-quires ISM!). $495, program;$129, upgrade. MicrosoftCorp., One Microsoft Way,Redmond, WA 98052-6399;tel.: 206-882-8080; fax: 206-883-8101.


-1

UNICORNELECTRONICS10010 Canoga Ave., Unit B-8Chatsworth, CA 91311

SINCE 1983 - YOUR I.C. SOURCE - AND MUCH MORE!!NO SHIPPING CHARGES ON PRE -PAID ORDERS!*

NO CREDIT CARD SURCHARGE!SCHOOL P.O.'s WELCOME!

WA -1 A ;1 ] [e]WAVE- OUTPUT OPER. OPER.

STOCK # MFG. 1-24 25-99 100+LENGTH POWER CURR. VOLT.

LS9220 TOSHIBA 660nm 3 mW 85 mA 2.5 V 129.99 123.49 111.14LS9200 TOSHIBA 670nm 3 mW 85 mA 2.3 V 49.99 47.99 43.19

LS9201 TOSHIBA 670nm 5 mW 80 mA 2.4 V 59.99 56.99 51.29



LS3200 NEC 670nm 3 mW 85 mA 2.2 V 59.99 56.99 51.29

LS022 SHARP 780nm 5 mW 65 mA 1.75 V 19.99 18.99 17.09

SB1053 PHILLIPS 820nm 10 mW 90 mA 2.2 V 10.99 10.44 9.40

WAO II PROGRAMMABLE ROBOTIC KITThe pen mechanism in-

cluded with the robot allows itto draw. In addition to drawingstraight lines, it can also accu-rately draw circles, and evendraw out words and shortphrases. WAO II comes with128 x 4 bits RAM and 2K ROM,and is programmed directly viathe keypad attached to it. Withits built-in connector port, WAOII is ready to communicate withyour computer. With theoptional interface kit, you canconnect WAO II to an Apple II,Ile, or11+ computer. Editing andtransfering of any movementprogram, as well as saving andloading a program can beperformed by the interface kit.The kit includes software.cable, card, and instructions.The programming language isBASIC.

Power Source 3 AA batteries (not included)

STOCK X DESCRIPTION 1-9 10-24 25+

MV961 WAO ll Programmable Robotic KitWIIAP Interface Kit For Apple II, 11E. II,

79.99 75.99 68.3939.99 37.99 34.19

PROTOBOARD DESIGN STATION

Air41.

41,

The total design workstation - includingexpanded instrumentation, breadboardand power supply.

Ideal for analog, digital and micro-processor circuits

8 logic probe circuits Function generator with continuously

variable size, square, triangle waveforms, plus TTL pulses

Triple power supply offers fixed 5 VDCsupply plus 2 variable outputs - +5 - 15VDC and -5 - 15 VDC

8 TTL compatible LED indicators, switches Pulsers Potentiometers Audio experimentation speaker Multiple features in one complete test

instrument saves hundreds of dollarsneeded for individual units

Unlimited lifetime guarantee on bread-board sockets

Fixed DC outputt5 VDC (n) 1.0 amp, ripple - 5 mV

Variable DC output+5 - to +15 VDC @ 0.5 amp. ripple -

5 roll

Variable DC output-5 - to -15 VDC (r/ 0.5 amp, ripple -

5 mVFrequency generatorfrequency range: 0.1 Hz to 100 KHz in 6rangesoutput voltage: 0 to i 10V (20 Vp-p)output impedance: 600 (except TTL)output current: 10mA max., short circuitprotectedoutput waveforms: sine, square, triange,TTLsine wave: distortion 3% (10 Hz to 100KHz)TTL pulse: rise and fall time 25nsdrive 20 TTL loadsSquare wave: rise and fall time 1.5 sLogic indicators8 LED's, active high, 1.4 volt (nominal)threshold, inputs protected to ± 20 voltsDebounced pushbuttons (pulsers)2 push-button operated, open -collectoroutput pulsers, each with 1 normally -open. 1 normally -closed output. Eachoutput can sink up to 250 mAPotentiometers1 - 1K , 1 10K , all leads availableand uncommittedBNC connectors2 BNC connectors pin available anduncommitted shell connected to groundSpeaker0.25 W, 8Breadboarding area2520 uncommitted tie pointsDimensions11.5" long x 16" wide x 6.5" highInput3 wire AC line input (117 V, 60 Hztypical)Weight7 lbs.

STOCK DESCRIPTION 1-9 10-24 25+

PB503 Protoboard Design StatIon 299.99 284.99 256.49

IDC BENCH ASSEMBLY PRESSThe Panavise PV505 1/4 tonmanual IDC bench assemblypress is a rugged. practical instal-lation tool designed for lowvolume, mass termination ofvarious IDC connectors on flatribbon cable. Assembly base & standard

platen included Base plate & platen may be

rotated 90* for maximumversatility

Base plates & cutting acces-sories are quickly changedwithout any tools required

Additional accessories below Size - 10" W x8.75" D x 9" H Weight - 5 5 lbs

COLLIMATING PENA low power collimator pen contain-

ing a MOVPE grown gain GaAIA5 laser.This collimator pen delivers a maximumCW output power of 2.5 mW at 820 rim.

The operating voltage of 2.2-2.5v @90-150mA is designed for lower powerapplications such as data retrieval,telemetry, alignment, etc.

The non -hermetic stainless steel caseis specifically designed for easy align-ment in an optical read or write system,and consists of a lens and a laser diode.The lens system collimates the diverg-ing laser light .18 mrad. The wavefrontquality is diffraction limited.

The housing is circular and precision manufactured measuring 11.0mm in diameter and 27.0 mm long. Data sheet included.

As with all special buy items. quantity is limited to stock on hand.

LASER DIODE MODULEThe LDM 135 integrated as-

sembly consisting of a laserdiode. collimating optics anddrive electronics within a singlecompact housing. Produces abright red dot at 660-685 em. It issupplied complete with leads forconnection to a DC power supplyfrom 310 5.25 V.

Though pre-set to produce aparallel beam, the focal lengthcan readily be adjusted to focusthe beam to a spot.

Sturdy, small and self-con-tained, the LDM135 is a precisiondevice designed for a wide rangeof applications 0.64" diam. x 2"long

STOCK DESCRIPTION 1-9 10-24 25. STOCK x DESCRIPTION 1-9 10-24 25- STOCK DESCRIPTION 1-9 10-24 25-

PV505 Pari,ivisr Ileouh Assembly Press 149 99 142.49 128 24 SE11052 Infra -Red Collimator Pen 49.99 47 49 42.74

COLLIMATING LENS DUAL MODE LASER POINTERThis economical collimatinglens assembly consists of ablack anodized aluminumbarrel that acts as a heat sink,and a glass lens With a focalpoint of 7.5 mm. Designed to fitstandard 9mm laser diodes.this assembly will fit all theabove laser diodes. Simplyplace diode in the lens assem-bly, adjust beam to desiredfocus then set with adhesive.

STOCK ol DESCRIPTION 1-9 10-24 25.

LSLENS COOSISSISO Loss Assembly 24 99 23 /4 21 37

STOCK DESCRIPTION

New slimline laser pointer is onlyin diameter x 6' long and weighsunder 2 oz . 670 rim @ less than 1mW produces a 6 mm beam 2switches, one for continuous mode,and one for pulse mode (red dotflashes rapidly). 2 AAA batteriesprovide 8- hours of use. 1 yearwarranty.

1-9 10-24 25-

LDM135-.5 5 mW Laser Diode ModuleLDM135-1 I mW Laser Diode ModuleLDM135-2 2 rriW Laser Diode ModuleLDM135-3 3 mW Laser Diode Module

179.99 170.99 153.89189.99 180.49 162.44199.99 189.99 170.99209.99 199.49 179.54

He-Ne TUBES

LP35 Dual Mode Laser Pointer 199.99 189.99 170.99

ROBOTIC ARM KIT

POWER SUPPLY Input, 115/230V

Output' +50 @ 3.75A0120 @ 1.5A-12v @ .4A

SIze 7"L x W x2 H

STOCK X PRICEPS1003 $19.99

Robots were once confined to sciencefiction movies. Today, whether they'reperforming dangerous tasks or puttingtogether complex products, roboticsare finding their way into more andmore industries. The Robotic Arm Kitis an educational kit that teachesbasic robotic arm fundamentals as wellas testing your own motor skills_Command it to perform simple tasks.

STOCK X PRICEY01 543.99

New, tested 632nm He-Ne lasertubes ranging from .5mW to 3mW(our choice) Perfect for hobbyistsfor home projects. Because of thevariety we purchase. we cannotguarantee specific outputs will beavailable at time of order. All unitsare new, tested. and guaranteedto function at manufacturersspecifications.

STOCK x DESCRIPTION -9 10-24 25-

LT1001 He -He Laser Tube 69.99 66 49 59.84

AVOIDER ROBOT KITAn intelligent robot that knows howto avoid hitting walls. This robotemits an infra -red beam whichdetects an obstacle in front and thenautomatically turns left and con-tinues on

STOCK X PRICEMV912 $43.99

ORDER LINE - (800) 824-3432 INTERNATIONAL ORDERS - (818) 341-8833FAX ORDERS - (818) 998-7975 TECHNICAL SUPPORT - (818) 341-8833

VISA

15.00 MINIMUM ORDER UPS BLUE. RED & FEDERAL EXPRESS SHIPPING AVAILABLE OPEN MON-FRI 9:00 AM - 6:00 PM, SAT 10:00 AM - 3:00 PM PDT CA RESIDENTS ADD 81/4% SALES TAX CALL FOR QUANTITY DISCOUNTS CALL FOR FREE CATALOG (FOR 1ST CLASS DELIVERY OR

CATALOGS DELIVERED OUTSIDE THE U.S. - SEND $2.00) WE CARRY A COMPLETE LINE OF ELECTRONIC COMPONENTS'NO SHIPPING CHARGES ON PRE -PAID ORDERS DELIVERED IN THE CONTINENTAL U.S.


What's New!

Windows/MacintoshFile TransferThe Windows version of Paci-fic Micro's Mac -In -DOS allowsfor transfer of Macintosh filesto and from an IBM/compati-ble computer via the IBM flop-py disk drive (1.44M only). Themain screen of Mac -In -DOS

shows Mac files on one side andPC files on the other. Files arecopied from one side to theother, with conversions takingplace automatically. Functionkeys perform the main DOSfile handling functions likechanging of directories, delet-ing files and copying files. $99.Pacific Micro, 201 San Anton-io Circle, Mountain View, CA94040; tel.: 415-948-6200; fax,415-948-6296.


Shortest -Route Trip PlottingSky Shepard Software hasfour new programs of interestfor small businesses and in-dividuals. TRIP and PRO -TRIP function as map/dis-patching programs for travel-ers and businesses that wantto route and track mileage.Users simply designate a start-ing and ending point, andTRIP plots the shortest routevia interstates and major UShighways. TRIP's databasecontains 2,500 locations. PRO -TRIP features an expanded

database with 7,000 locations.$60 for TRIP; $250 for PRO -TRIP.

Mailsaver is a sophisticatedduplicate -elimination pro-gram for mailing lists. It findsphonetic as well as exactmatches, common nicknamematches, transposition er-rors, same-household/same-address records and same in-dividual with multiple ad-dresses. $395.

General Manager is a newsports card inventory program


designed for serious collectors.The program generates 10 re-ports designed to help collec-tors quickly discover the valueof their collections, totalamount invested and percen-tage of increase or decrease invalue. The program also incor-porates scanning capability,making it possible for collec-tors to see a specific card on-screen. $50. Sky Shepard Soft-ware, P.O. Box 49, St. Marys,IA 50240; tel.: 515-255-9300/800-397-0924.

Console/Computer Switch

The SC-6X3-15V6M from Net-work Technologies is a six -con-sole (keyboard and monitor) -by -three -computer matrixswitch that permits up to sixconsoles to be connected to upto three computers. It supportsVGA monitors and keyboardswith six -pin mini -DIN connec-tors and operates remotelywhen the RMT-3C control unitis used with a console. The re-

mote -control unit has a seven -segment display for showingwhat keyboard is connected toeach computer. Only one key-board can be attached to eachcomputer at a time, but all sixmonitors can be connected toa single computer.

The SC-6X3-15V6M consoleswitch is housed in a plasticcase that measures 5.5 " x11.5" x 19" and requires 117

or 220 volts ac. $2,700, switch;$105, remote. Network Tech-nologies Inc., 7322 PettiboneRoad, Chagrin Falb', OH 44022;tel.: 216-543-1646; fax:216-543-5423.


SOUND MASTER® IITHE MOST COMPATIBLE PC -AUDIO CARD IN THE WORLD

100% AdLlb - compatible. 11 VoiceFM Music Synthesizer.

Exclusive SMULATOR- sound fileconversion software. Operates "SoundBlaster compatible titles - WITHIMPROVED SOUND DUALITY!

VOICE COMMAND SOFTWARE. Covox Voice Master®, Speech Thing®,

MIDI Maestro- compatible. 8 bit DMA sound digitizer. Sample

rates to 25Kbytes/sec with "direct todisk" recording and playback option.

MIDI Interface with simultaneous inputand output. Includes PC-LYRA- musiccomposition software .

4 -watt (peak) audio amplifier withadjustable volume control.

Internal PC speaker supported.Improves sound from any softwareusing the PC's internal speaker.

Audiophile sound quality. Low noise,precision engineered electronics.

Extensive software tools and support,including digital audio compressionand editing utilities.

Supported by the largest library ofsoftware titles In entertainment,business, music, and education.

Dual 3 -inch speakers,6 foot MIDIcable, and internal speaker bypassconnector included.

Made in USA by Covox THEmicrocomputer audio specialist since1975.

Your Best Choice for Multi -Media SoundONLY $229.95 (plus $5 shipping & handling)

ORDER HOTLINE: (503) 342-1271 M -F 8 AM TO 5 PM PST. VISA, MC,AMEX phone or FAX orders accepted. NO CODs. 30 day money backguarantee If not satisfied. One year warranty on hardware.

TRADE -UP OFFER: Your current PC sound card brand is worth $$$toward the purchase of a Sound Master II. Contact Covox for details.

CALL OR WRITE FOR FREE PRODUCT CATALOGcoliox INC. 675 Conger Street Eugene, OR 97402

Phone (503) 342-1271 FAX 503-342-1283 T0h161.0


10 / COMPUTERCRAFT / May 1992

Fix Dead PC's withQUICKPOST PC PLUSTM

IckPost -PC P1C, COPYRIGHT 1®1 ULTRR-,,,

Eliminates down time Quick and easy installation Uses the latest in decoding technology

QuickPost-PC Plus is a full -featured, plug-in hardwarediagnostic card that allows you to monitor the POST (PowerOn Self Test) sequence generated by the system BIOS duringpre -boot. With its proprietary memory address selectioncapability, QuickPost-PC Plus can test virtually any systemwhose BIOS outputs POST codes. This Card will work on allPC/AT/286/3861486, compatibles and even EISA system boards.

Call: 800-722-3789 408-988-4721 CA.Ultra -X, Inc.

Diagnostics for the ProfessionalP.O. Box 730010, San Jose, CA 95173-0010

VISA/Mastercard accepted Federal Express available

Learn to troubleshoot andservice today's computersystems as you build apowerful 386sx/20 MHzcomputer!

Train the NRI way-and learn toservice all computers as you buildyour own powerful West Coast386sx/20 MHz computer, nowwith 1 meg RAM, 40 meg IDEhard drive, and excitingnew diagnostic hardwareand software!

Jobs for computer service technicianswill almost double in the next 10 years according to Departmentof Labor statistics, making computer service one of the top growthfields in the nation.

Now you can cash in on this exciting opportunity-eitheras a full-time industry technician or in a computer service businessof your own-once you've mastered electronics and computers theNRI way.

Get real -world skills as you train with andkeep a powerful 386sx-based computersystem plus Microsoft' Works software

Only NRI gives you hands-on training with the finest example ofstate-of-the-art technology: the powerful new West Coast 386sx/20 MHz computer. As you assemble this fully IBM PC/AT-compatible machine, you actually see for yourself how eachsection of your computer works.

You assemble and test your computer's "intelligent"keyboard, install the power supply and 51/4" high -density floppydisk drive, then interface the high -resolution monitor.

Your hands-on training continues as you install a powerful40 meg IDE hard drive-today's most -wanted computer periph-eral-now included in your course to dramatically increase yourcomputer's data storage capacity while giving you lightning -quickdata access.

Plus you now work with today's most popular integratedsoftware package, Microsoft Works, learning to use its word proces-sing, spreadsheet, database, and communications utilities for yourown personal and professional applications.

But that's not all!

NEW! Ultra -X diagnostichardware and software forfast, accurate troubleshooting

Now you train with and keep thelatest in diagnostic hardware andsoftware: the extraordinaryR.A.C.E.R. plug-in diagnostic cardand QuickTech menu -drivensoftware, both from Ultra -X. Usingthese state-of-the-art tools, youlearn to quickly identify andservice virtually any computerproblem on XT, AT 80286/80386,and compatible machines.

NEW!386sx/20 MHzcomputer, 40 meghard drive!

Only NRI gives yousuch confidence -building, real -world experience. Only NRI gives youboth the knowledge and the professional tools to succeed astoday's in -demand computer service technician.

No experience needed...NRI builds it in

With NRI training, you learn at your own convenience in yourown home. No classroom pressures, no night school, no need toquit your present job until you're ready to make your move.

NRI starts you with the basics of electronics and computers,building on that foundation step by step until you have theknowledge and skills you need for success.

And all throughout your training you've got the fullsupport of your personal NRI instructor and the entire NRItechnical staff, always ready to answer your questions and helpyou achieve your training goals.

Send for your FREE catalog today!

Send today for NRI's big, free catalog that describes every aspect ofNRI's innovative computer training, as well as hands-on trainingin other growing high-tech career fields.

If the coupon is missing, write to: NRI Schools, McGraw-Hill Continuing Education Center, 4401 Connecticut Avenue,NW, Washington, DC 20008.

IBM and AT are registered trademarks of the IBM Corporation. RACER. and QuickTech areregistered trademarks of Ultra -x, Inc. West Coast is a member of the Syntax Group.

SEND CARD TODAY FOR FREE NRI CATALOGmct;raw-ttill continuing

Schools 4401 Connecticut Avenue,

e Check one FREE catalog only

MICROCOMPUTER SERVICINGE TV/Video/Audio ServicingE TelecommunicationsE Industrial Electronics & RoboticsE Security ElectronicsE Electronic Music TechnologyE Basic Electronics

uca ion CenterNW, Washington, DC 20008

E Computer ProgrammingO PC Software Engineering Using C Desktop Publishing & DesignEl Word Processing Home BusinessE Bookkeeping & AccountingIE Air Conditioning, Heating, & RefrigerationEl Building Construction Small Engine RepairO Automotive Servicing

[1 For career coursesapproved under GI Bill,check for details.

Name (please print) Age

Address

City/State/Zip Accredited Member, National Home Study Council 4-052

What's New!

Single -Board EISA486 CPU CardDiversified Technology's ESP -2000 i486 -based EISA CPUcard is designed for passivebackplane architecture. Oper-ating at 33 MHz, it incorpo-rates Intel's 82350DT chip setand uses a CPU -to -memoryprotocol that allows the mem-ory subsection to operate inde-pendently of the CPU clock fora smooth transition to 50 -MHzoperation. Up to 64M of sys-tem memory is supported viaSIMMs. The card supports an

optional Intel Turbo cachemodule (both 64K and 128K).The EISA-bus DMA channelscan operate in both 8- and 16 -bit modes with EISA/ISA busslaves and masters and 32 -bitmode with EISA slaves andmasters. $2,595 (OK memory).Diversified Technology, POBox 748, Ridgeland, MS39158-0748; tel.: 601-856-4121.


Quick -Connect Barcode ReaderThe newest model PERCONSeries 20 Universal barcodeand magnetic -stripe decoderuses quick -release front -paneljacks to connect any two bar-code input devices at once. Bar-code input devices offered byPERCON include a selectionof wands, CCDs and laserscanners, plus ID -badge scan-ning heads. The sophisticateddecoder automatically differ-entiates between input fromtwo barcode devices and multi-ple magnetic -stripe readers, allof which can be connected atthe same time.

Universal decoders permitprogramming parameters to beentered in any of four ways:downloading programmingfiles in a batch mode, scan infrom PERCON-supplied bar-codes; scan in from user -print-ed Code 39 labels or set throughan interactive on -screen menu.Percon Series 20 decoders pro-

vide for data input editing,auto -host recognition, full key-board support and automaticdetection among 13 differentbar code symbologies. $735.

The PocketReader, alsofrom PERCON, is a 12 -ounceshirt -pocket-size portable bar-code reader that includes up to1M of memory, a Windowsprogramming environmentand the strength to withstand5 -foot drops onto concrete.PocketReader is easily pro-grammed with PERCON Pro-gram Generator software. Thestandard wand tip is suitablefor even marginal bar code lab-els and for narrow bar widthsdown to 0.007" (7 mils). A4 -line x 16 -character LCD dis-play provides operator promptsand messages, and users canscroll through and review up to24 lines of data held in an inter-nal display buffer.

Nineteen splash -resistant

keys enter both numeric andalpha data, and four user -pro-grammable function keys areincluded. Audible feedback isprovided through an adjust-able -volume speaker. The de-coder is compatible with a va-riety of data -collection net-works and uses an RS -232C in-terface and flexible menu -driv-en communications protocols.$735, Series 20; $490, Pocket -Reader. PERCON, Inc., 1710Willow Creek Circle, Ste. 37,Eugene, OR 97402-9153; tel.:800-873-7266; fax: 503-344-1399.


PLCC Extraction ToolOK Industries has a newPLCC extraction tool for theSMT assembly and reworkmarket. The EX -5 is designedfor single-handed extractionof 20- to 84 -pin PLCCs fromany socket. The tool's spring -

loaded one -hand design re-quires no pulling. By simplysqueezing the handle, theEX -5 lifts the chip from thesocket. It features ESD-safeplastic and metal constructionfor safety and durability. $20.OK Industries, 4 ExecutivePlaza, Yonkers, NY 10701;tel.: 914-969-6800.


Low -End DMMsBeckman's new DMSXL joinsthe DM15XL and DM1OXL inthe company's line of low -endDMMs. The line features 0.7"LCD numerals, 10 -amperecurrent fusing, warning beeperwhen test leads are placed inthe wrong input jacks, safetytest leads with shrouded inputplugs and test points and in-creased battery life.

Model DM (replacesDM10) includes a continuitybeeper and a "Safety Tester"feature. It detects and displayscommonly encountered ac and

dc potentials from 6 to 220volts. This special safety fea-ture works even when theDMM's battery is dead, ensur-ing that the user can alwayssafely detect the presence oflive voltage levels.

Model DM15XL (replaces

DM15) has all features of theDM1OXL and adds a logicmeasurement function that in-dicates the presence and polar-ity of TTL pulses up to 10MHz in frequency. All threemeters measure dc to 1,000volts, ac to 750 volts and resis-tance, and all feature a diode -test continuity beeper. $35,DMSXL; $45, DM1OXL; $60,DM15XL. Beckman In-dustrial Corp., 3883 RuffinRd., San Diego, CA 92123-1898; tel.: 619-495-3200.


High -Speed Serial Card

The FORVAL Turbo Inter-face is a multi -purpose serialadapter card for PC commu-nications. It is a proprietaryhigh-speed, two -port, serialcommunication board in ahalf -card format. It can en-sure data integrity at speedsup to and exceeding 114 Kbps.The Turbo Interface workswith all vendors' high-speedserial peripherals to protectPCs against dropped data.

The PC's ability to acceptdata from the serial port is thelimiting factor in high-speedserial communications withlimits of around 19 Kbps,while high-speed modems canoperate in excess of 56K bps.Error -correcting transmissionmodems are not capable ofdetecting and correcting datacorrupted by the CPU -to -seri-al -port link. The Turbo Inter-face solves this problem. $275.

Forval America, Inc., ModemDiv., 28241 Crown ValleyPkwy., Suite F-440, LagunaNiguel, CA 92677; tel.: 714-347-0100; Fax: 714-347-0200.



What's New!

Hand -Scanner Image StitcherThe CAT Image Enhancer 256software package gives you theability to seamlessly combinetwo halves of one image to pro-duce professional gray -scale -quality digital images. Addi-tionally, it converts ditheredhand scanners into true 256 -gray -scale scanners. It also of-fers sophisticated control overcontrast, brightness, aspect ratio, cropping and more and au-tomatically corrects imagesthat are skewed, compressed oruneven in brightness.

The package includes pro-cedures for customizing T-shirts and creating poster -sizeimages. Automatic ContrastControl Enhancement (ACCE)automatically sets the upperand lower contrast limits foroutput. Format conversions

for TIF, TIF 16 Gray, TIF 256Gray, Pallet.TIF, PCX, CUT/PIC, GIF and BMP are includ-ed. The program supports Ep-son/IBM graphics, HP Inkjetand HP LaserJet printers.Scanners supported includeGeniScan GS -2000 Plus/4000/4500/B105G, Logitech Scan-Man/ScanMan Plus/Scan-Man 32/ScanMan 256, Mars-tek Mars 105/105 Plus/800Hand Scanner, Mouse SystemsPageBrush/32 and numerousothers. Minimum require-ments are: VGA or SVGA,DOS 3.1 or later, 640K RAMand hard disk with at least 3Mfree (recommended). $129.Computer Aided Technology,Inc., 10132 Monroe Dr., Dal-las, TX 75229; tel.: 214-350-0888; fax: 214-904-0888.


SBus Interface ChipAccurite Technologies has anew SBus interface IC and acorresponding eight -bit SBusdeveloper's kit. Using the ICand kit, developers can savetime and cost while maximizingefficient usage of printed -cir-cuit board "real estate." It fea-tures a 32 -bit SBus data path,eight -bit peripheral data path,up to 15M byte -per -secondthroughput, burst -mode datatransfers and 13 -bit buffered

peripheral address lines thatcan be held or incrementedwith each byte transferred.

This highly integrated100 -pin PQFP IC package oc-cupies 0.7 sq. in. of board areafor its interface, compared tothe approximately 29 devicesneeded for a simple PAL im-plementation. $695, develop-er's kit; $30, SBus IC. AccuriteTechnologies, Inc., 231 Char -cot Ave., San Jose, CA 95131-1107; tel.: 408-433-1980; fax:408-433-1716.


NotebookComputersDauphin Technology is cover-ing both ends of the notebooktype -computer spectrum withits new 500 series notebookcomputers. The 500-88 is con-

figured with an Intel 8088microprocessor, 1M RAM,and a 3% " 1.4M drive. A 20Mhard disk is optional. TheDauphin 500-SX features a20 -MHz 386SX, 1.4M floppy,2M RAM, and either a 20M or60M hard drive. Each unit in-cludes a built in KeyMouseand weighs in at under sevenpounds with battery. The casemeasures 11" x 8%" x 4".Dauphin Technology Inc.,1125 E. St. charles Rd., Lom-bard, IL 60148; tel.: 708-627-4004; Fax: 708-627-7618.


Shareware From PC -SIGDOS Shareware UtilitiesBy Ed DiGiovanna(Windcrest /McGraw-Hill.Soft cover. 204 pages.$29.95.)

This book and disk packagepresents an easy -to -read,easy -to -understand descrip-tion of 18 of the more popularDOS utilities offered asshareware by PC -SIG. Ahandful of the utilities cov-ered are included as evalua-tion copies on a 360K disk in-cluded with the package.

The utilities are divided in-to seven chapters, coveringmemory management, diskutilities, graphics, user inter-face, catastrophe insuranceand printer utilities. Eachcovers several utilities fallinginto the category. Enough in-formation is included to al-low the reader to "get a feel"for how the program works.

The author also includesregistration informationfor each program. Among

the programs detailed, Re-config permits storing severaldifferent configurations ofyour AUTOEXEC.BAT andCONFIG.SYS files for selec-tion during boot -up; OnSideis a "sideways" printing utili-ty for spreadsheets and simi-lar programs; VMS40 is autility that uses disk space toemulate EMS; CMOS-RAMis a utility that reads andstores setup data from an AT -class computer for simplifiedreconfiguration when thebackup battery fails; Zip is acompression utility; and Vir-uscan covers virus detectionand removal. But with detailson how to use programs thatyou don't have, the book is inpart self -promotional, withsoftware order forms includ-ed. As such, its value wouldbe limited to novices whowant to get insight into a vari-ety of program types avail-able as shareware (and regu-lar commercial equivalents).

Electronics EnclosureExtrusion Technology has anew line of extruded aluminumenclosures that are suitable forprototyping, beta testing, andfull production. Tech -Box isavailable in four sizes rangingfrom 3" x 1" to 6" x 2%".Boxes are available with circuitcard slots for card widths of3.00" to 6% ". Numerous off -the -shelf lengths are available

as are custom lengths from %'to 12 ' . The boxes are suppliedwith matching panels contain-ing custom hole patterns and achoice of finishes. $5.15 andup. Extrusion Technology, 80Trim Way, Randolph, MA02368; tel.: 617-963-7200; fax:617-963-7203.


Cross AssemblersLogisoft has a new line ofDOS -compatible ProfessionalOptimized Cross -Assemblerswritten in assembly language,resulting in fast assembly.Powerful two -pass relocatablemacro assemblers and absoluteversion are available. Relocat-able assembler packages fea-ture a two -pass Linker to re-solve forward references be-tween modules. The linker canhandle an unlimited number ofmodules. An independent"Locate" utility allows you torelocate without relinking. Allpackages include an objectcode format conversion utility,to provide system compatibility.

Cross -assemblers are avail-able for 8051, 8048, 8080/85,68000, 6800, 6805, 6809,68HC11, 6301/03, 6502/65002,Z80/180, 9900 and other com-patible manufacturers' fami-lies of microprocsessors andmicrocontrollers. $99 and up.Logisoft, PO Box 61929, Sun-nyvale, CA 94086; tel.: 408-773-8465; fax: 408-773-8466.


(continued on page 83)


Upgrading By Tom Carlton

Removable Mass -StorageSCSI Cartridge Drives

Relieves the perennial problem of running outof hard -disk space

Even after purchasing that 200Mhard drive you've been wanting

for a long time, why is it that the totalamount of your file space always ex-ceeds the capacity of your hard drive?If you find yourself in this dilemmaoften and have given up on compres-sion software and floppy disks, lookinto virtual mass storage. Combiningan efficient SCSI (Small ComputerSystems Interface) host adapter, pro-nounced "scuzzy," with a removabledisk cartridge drive may change yourview of personal computing.

With virtual mass storage you'll nolonger fret and fuss, spending longhours backing up files on floppy disks.Nor will you constantly sort throughand decompress files on floppies orhard drives. Adopting removablemass storage can lower your level offrustration and increase your efficien-cy and organization, and an addedbenefit is that you'll establish sounddata security.

Installing a SyDOS RemovableCartridge Drive kit may be your easi-est option in this area, though it isn'tlikely to be the least -expensive way togo. SyQuest drives-the basic car-tridge drive units-are readily avail-able from distributors and retailers, asare SCSI host bus adapters (HBAs).SyDOS and several other vendors of-fer this basic drive unit bundled withan SCSI host adapter, cables, softwareand documentation.

SCSI DefinedBefore we get into the mechanics of in-stalling a removable cartridge drive kitin your computer, it's a good idea foryou to become acquainted with theworld of SCSI. Basically, SCSI is a

standard bus for connecting intelligentperipheral devices to small computers.It isn't the same as the internal AT busover which the CPU communicateswith memory.

Shown in Fig. 1 is a comparison ofsystems that use an SCSI system -levelinterface and ST506 device -level inter-face. Notice that ST506 functionsfound on the controller are located onthe intelligent SCSI device. An SCSIadapter with its own BIOS providesthe interface with the CPU and RAM.Thus, the intelligence of peripheraloperations is moved from the CPU tothe peripherals.

Of the two electrical (pin -assign-ment) options available, the single -ended driver/receiver option depictedin Fig. 2 is the more common. The dif-ferential driver/receiver is the otheroption. The asynchronous protocol,

similar to the IEEE -488 bus used byHewlett-Packard, has a nine -bit par-allel bus, handshake protocol usingthe I/O signal line (direction signal),request (REQ) and acknowledge(AcK). Each command or data bytetransferred uses these signals. Detailedinformation on this standard is con-tained in the "Small Computer Sys-tem Interface" published by and avail-able from the American NationalStandards Institute.

Several Drive OptionsSyQuest drives come in 44M and 88Mversions. SyDOS, a division of Sy -Quest, offers drives of both capacitiesas internal and external upgrade kits.It also offers a dual -drive external unitfor these two storage capacities. Sev-eral other third -party vendors offersimilar configurations.


CPU

SYSTEM USING ST506 INTERFACE

SYSTEMBIOS

RAM lHCONTROLLER

FORMATTING, ECC, HEAD SELECT,CYUNDER SELECT, DATA SEPERATION,ENCODE/DECODE, ADDRESS MARKDEFECT

DRIVE

READ/WRITESEEK

SYSTEM USING SCSI INTERFACE

SYSTEMBIOS

ADAPTER 141

(OWN BIOS)

RAM

SCSI DRIVEFORMAT1NG, ECC HEAD SELECT,CYUNDER SELECT, DATASEPERATION, ENCODE/DECODE,ADDRESS MARK DETECT,READ/WRITE, SEEK, DEFECTHANDLING

Fig. 1. An SCSI bus moves the intelligence from CPU to SCSI device. This device -independence offers flexibility by notrequiring additional controllers when adding new devices.

Giving up some of this pre-pack-aged convenience to save a few hun-dred dollars, you'll find several alter-native solutions. However, none is asconvenient, flexible and affordable asthe combination of a 16 -bit AlwaysTechnology IN2000 SCSI host adapt-er with a SyQuest Removable Car-tridge Disk Drive.

Street prices vary, but you can setup a 44M drive for well under $600 oran 88M unit for less than $800. Car-tridges sell for as little as $69 for 44M(SQ400) and $119 for 88M (SQ800)units. If you decide on a single 44Mdrive, an eight -bit adapter can saveyou another $100. Thus, you have twobasic installation options-third-party kits and purchasing a drive andadapter separately.

I installed a SyDOS 88e (the drivekit numbers have an "e" suffix for ex-ternal and an "i" suffix for internalunits) and a SyQuest SQ555 (44M in-ternal) in two '386 computers. Onecomputer is a run-of-the-mill clonehoused in a standard AT case; theother is a Northgate Slimline com-puter. The former had a 200M SCSIhard drive, the latter a 120M IDEdrive. Both installation options tookless than an hour to complete, in-cluding reading directions.

SyDOS Installation

The SyDOS 88e kit comes completewith everything needed for successfulinstallation. In addition to the SCSIhost adapter card, cartridge drive, onecartridge and 50 -pin Centronics cable,SyDOS provides utility software fordiagnosis, cartridge formatting andSuper PC-Kwik disk caching.

Installation consists of just fouralmost -foolproof steps, as follows:

(1) Using the SYPREP utility, youobtain a drive table that provides aROM map of addresses for existingdevices. Most address conflicts can bedetermined using this utility, allowingyou to set jumpers on the host adapterto resolve any conflicts.

The host adapter is compatible withmost standard hard -disk controllers,including ST506/412, IDE, ESDIand, of course, SCSI. I had a problemwith a DTC RLL controller card in a286 and was unable to rectify the con-flict. If you run into a problem withany of the few 16 -bit VGA cards thatdo cause conflicts, you can giveSyDOS technical support a call at800-43SYDOS to obtain a list ofrecommended cards.

When running SYPREP, you havethe option of installing the SYDRIV-

ER.SYS device driver and updatingyou CONFIG.SYS file. If you preferto do this yourself, copy the driver toan appropriate directory and add "de-vice =x: \ x \ SYDRIVER.SYS" toyour CONFIG.SYS file.

(2) Next, power down your systemand disconnect all power sources.Then remove the cover from the sys-tem unit and locate an available 16 -bitexpansion slot. Remove the coverplate from the rear access panel forthis slot, and plug the Adaptec 1540SCSI host adapter into the slot. Thisdone, secure the adapter with thebracket -retainer screw and replace thecover on the system unit.

(3) Connect the external drive to theadapter via the Centronics cable. Ifyou're installing a single drive (onlyone SCSI device), set the SCSI IDnumber to 0 (read the "recession op-tion" for more details on SCSI ID).Power up your system and cartridgedrive, reboot, and you're in business.

(4) You'll need to format a cartridgeusing SYPREP or DOS FORMAT,the difference being that SYPREPcopies the device driver to the cartridgeif you decide to format it as a bootabledisk. You can make this your bootdrive, which is very convenient if yourun under multiple environments,


such as DOS, OS/2, Windows, UNIXor any unique configurations of anyone of these.

Installing an internal unit is exactlythe same, with the exception that youneed a 5 Y." half -height bay in which tophysically mount the drive, a 5 -voltconnection and an internal SCSI ca-ble. Install internal units just as youwould a floppy -disk drive. Make sureyou get a 50 -pin SCSI cable when youpurchase the drive or adapter, sincesuch cables can be hard to find.

If you install two or more drives in-ternally or externally, you must "dai-sy -chain" them. This requires a cablewith a 50 -pin connector for each ad-ditional drive.

Recession OptionIf you have more time than money, in-stalling individual components offersreal savings. You can save $200 ormore by going this route.

The IN2000 SCSI adapter provides

excellent performance. Like theAdaptec 1540, it'll handle up to sevenSCSI peripherals, including tapedrives, CD-ROMs and scanners in adaisy -chain scheme. Additionally, thisdevice supports two floppy drives, asdoes the Adaptec 1542B adapter.

When you daisy -chain several de-vices, you must assign logical devicenumbers from 0 to 7. These ID num-bers have no effect on non -SCSI de-vice numbers used by your computer(the ones established in your CMOSSetup procedure). External units pro-vide a convenient pushbutton switchon the back of their cases for selectingID numbers. Internal drives requireyou to place a jumper plug over theproper pins at the rear of the drive.SyDOS and SyQuest documentationprovides clear illustrations for thisprocedure.

You must also install terminator re-sistors in the last logical drive and onthe adapter. These resistors are sup-plied with these devices. If you install

SCSI 50 -Way Bus Single -Ended Pin Assignments

SIGNAL LINE PIN GROUNDRETURN PIN

SIGNAL NAME

-DB(0) 2 1

DATA BUS

-DB(1) 4 3

-DB(2) 6 5

-DB(3) 8 7

-DB(4) 10 9

-DB(5) 12 11

-DB(6) 14 13

-DB(7) 16 15

-DB(P) 18 17 DATA BUS PARITYGROUND 20 19

GROUND 22 21

GROUND 24 23TERMPWR 26 25 TERMINATOR POWERGROUND 28 27GROUND 30 29-ATN 32 31 ATTENTIONSPARE (GROUND) 34 33-BSY 36 35 BUSY-ACK 38 37 ACKNOWLEDGE-RST 40 39 RESET-MSG 42 41 MESSAGE-SEL 44 43 SELECT-C/D 46 45 CONTROL/DATA-REO 48 47 REQUEST-I/O 50 49 INPUT/OUTPUT

Fig. 2. Pin 25 should be left open, while all other odd pins should be connectedto ground. A minus sign indicates active low.

more than one device, remove the re-sistor packs from all logical drives, ex-cept the last one.

Installation of a SyQuest drive andIN2000 adapter is identical to that forthe SyDOS kits. Just make sure youhave all components: SyQuest driveunit (44M SQ555 or 88M SQ5110)with rail kit or external power supplywith case, adapter card and internal orexternal cables. Don't forget the car-tridge, SYPREP software and devicedriver. If you connect an externaldrive to the IN2000 adapter, the cablemust have 25 -pin (DB-25) and 50 -pinCentronics interface connectors.

PerformanceMoving data at 5M/s, these SCSIcards kick sand in the face of standardhard -drive interfaces. Of course, theAT bus can't move this fast, and fewESDI or SCSI hard drives reach halfthis speed; most transfer at around1M/s. Depending on block size, thecartridge drives will perform at onlyabout 600K to 800K/s, and transferspeed can be as low as 300K/s forsmall block sizes.

These cartridge drives maintainrespectable average seek times of 20ms, which compare favorably to manyhard drives. Effective seek times areeven better. Overall, the performanceof these drives seems like lightningcompared to floppy drives, but it'ssomewhat sluggish when compared toESDI and SCSI hard drives.

Reliability Security & MobilityThe 44M and 88M drives have anMTBF (mean time before failure) of30,000 and 60,000 power -on hours, re-spectively. My two years of experiencewith the cartridges have been withouta single problem (the drives carry afive-year warranty).

Since the cartridges aren't hermeti-cally sealed, they can be subject to dustcontamination. Taking a brave step ayear ago, I tossed a cartridge throughthe air-data and all-across a 12 -footroom to have it land on a carpetedfloor. I certainly don't recommendthat you attempt this. I was just try-ing to ascertain if the cartridge couldsurvive such rough handling. It did.

Another point to consider is com-patibility between the two formats, aswell as with the Apple Macintosh. TheSQ5110 (88e/i) reads only 44M car -


TO

PC

EXPANSION

BUS

TO EXTERNALSCSI DRIVE

HBA Connection

SCSIHOST

ADAPTER

SCSI ID Jumpers

Terminating Resister Pack

Host Bus Adapter Connection

I- -I(Internal)

DC PowerConnector

Fig. 3. Installation requires a 16 -bit slot for the SCSI host adapter and a51/4" half- height bay for an internal SyQuest drive.

tridges. The drives used for the PC andMac are identical. In fact, I can plugthe same drives I installed in my PCcompatibles into the SCSI port on aMac. Of course, for the Mac to readfrom and write to the cartridges, theymust be formatted for the Mac envi-ronment. Thus, these drives offer agreat deal of flexibility.

When you consider the ability toeasily remove a cartridge that containsimportant data or a backup of yourhard disk and keep it secure in a vaultor other safe place, the extra cost com-pared to a conventional hard drive iseasy to rationalize.

If you can't be without a laptopcomputer, SyDOS has announced anew parallel -to -SCSI adapter to meetyour needs.

The ease -of -use, straightforwardinstallation and affordable price of aSyQuest removable cartridge drivemakes this an option worth consider-ing when you're faced with notenough hard -drive space for all your

applications and utility software. Be-cause the cartridges are removable andyou can buy extra ones at any time,you can easily back up your hard diskin a convenient manner.

Another benefit of using removablecartridge drives is the ability they giveyou to organize your work area forbetter efficiency. Using separate car-tridges, you can group together relatedapplications on separate cartridges sothat all the applications you need at asession can be "on-line" when youneed them. For example, if you're in-to DTP, you can place on one car-tridge desktop -publishing, font -gen-erating, clip art -library and word-processing packages. On another car-tridge, you can have your paint anddraw programs. On yet another car-tridge, you can have all the softwareyou need for desktop video, and onstill another cartridge you can have thedifferent types of CAD programs youroutinely use. Needless to say, thepossibilities are limitless.

Names & Addresses

SyDOS 44i, $799SyDOS 44e, $1,039SyDOS 88i, $1,439SyDOS 88e $1,539SyDOS6501 Park of Commerce Blvd., Se. 110Boca Raton, FL 33487Tel.: 800-43SYDOS


Sold only sold through distributors; pricevariesSyQuest Technology47071 Bayside Pkwy.Fremont, CA 94538Tel.: 5101-226-4000CIRCLE NO. 175 ON FREE INFORMATION CARD

IN2000, $249Always Technology31336 Via Colinas, Ste. 101Westlake Village, CA 91362Tel.: 818-597-1400



Application By Yacco

Memory ManagementPart 1

Techniques that fit large programs into the userRAM from 0 to 640K by moving as many resourcesas possible into high memory beyond 1M

your personal computer is cleverenough to work all of its tricks in

only one relatively small corner of itsbrain. In earlier days, there was onememory area in which it would put allthe programs you run (your applica-tions), all your pop-up utilities (resi-dent programs) and all operating -sys-tem extensions (installable device driv-ers). A later strategy for increasing thecomputer's performance is to con-serve that speck of memory for run-ning only the code that can't go any-where else: your applications. To dothis, all drivers and resident programsmust be put into areas where theywon't bump into each other, butwhere they're conveniently accessiblewhen needed.

This takes memory management. Ifyou're planning to buy many new ap-plications for your personal com-puter, you'll also need to get a utilityor operating system that can manageevery byte, bit and ephemeral wisp ofmemory you've got. Otherwise, yourspiffy new applications may run notvery well, or not at all. You'll likely usea memory manager because with to-day's powerful programs, you can'tjust squeeze everything into the 640Kmemory box allotted to you.

What is memory management? It'sthe technique whereby vastly over-ambitious programs are fit into thegrossly inadequate random-accessmemory (RAM) resources availableon commodity personal computers.This constant directly results fromstructural constraints imposed by boththe Intel processor family (the 8086and 80X86 chips used in IBM/com-patible microcomputers) and the DiskOperating System (DOS) that was de-signed and built within its confines.

0

Conventional

9FFFF

Upper

FFFFF

1OFFEE

Shadow

HMA

Extended

Hardware Model 1.80286 with Chips& Technologies ChipSet, CompaqTOPS384, Micronics, Trillion, etc.This is the first of eight such memorymodels. Find the model that corres-ponds to your hardware configuration.The corresponding memory maps willhelp you determine how to configurethe memory in your computer.

All DOS memory -managementtechniques and products are basicallykludges that have been developed toovercome the limitations inherent inpersonal computers. In short, it's awonder that the whole thing works atall. But it does-sometimes, it does sorather well.

Knowing how memory managerswork is, fortunately, not a require-ment. However, you'll be better ableto select from among management

utilities, and get much more out ofone, if you're familiar with theirabilities. It helps to know about yourcomputer, too: its memory and limita-tions, the memory services a managercan make available with it and whichprograms work with each.

This month, we focus on the variousmeans for efficiently managing mem-ory. Next month, we'll conclude withdescriptions of Microsoft MS-DOS5.0 and Digital Research DR DOS 6.0and review a variety of products thatimprove upon the basic resources in-cluded in these two operating systems.

ProcessorsWhile Intel microprocessors areultimately responsible for most of ourmemory -management headaches,problems vary with the specific chipused in a given computer. Early onesdefined a troublesome nonlinear ad-dress space. Later chips maintainedthe ability to confound and befuddleus, mostly to ensure compatibilitywith software designed for earlierones. But later chips also have ad-vanced features that new operatingsystems and memory managers canuse to advantage.

The 8086 (and 80186, 8088, 80188,NEC V20 and V30 variations) is thedull sibling to which all the other chipsin the Intel family must conform, andthe one by which they're limited. The8086 was the first 16 -bit chip in the In-tel processor line. Its 16 -bit registersize, instruction set's addressingscheme and 20 address lines limit it toaddressing 1 megabyte (IM) of userRAM memory.

At the time it was designed, no oneimagined that a personal computer


0

9FFFF

Conventional

FFFFF

Upper

1OFFEE

HMA

Extended

Hardware Model 2. Computers with80386 or i486 CPU and RAM installedat upper addresses.

would ever need as much as a millionbytes for temporary storage of pro-grams and data and the operating sys-tem. After all, the eight bits in just asingle byte can store quite a lot of data:a fairly large integer (65,536), eightswitch settings or any one of 256 char-acters. Selecting 1M as the extent ofmemory space must have seemed likean extravagance. (Note: Extendedmemory isn't available for 8086 and8088 CPU -based systems, not evenwith the help of a memory manager.)

The 80286 and BeyondWhen the 80286 was created, its de-signers included the ability to addressup to 15M of memory beyond the firstmegabyte-an area called "extendedmemory." Assuming it has been in-stalled, the addition of extendedmemory would seem to offer a vasttotal of 16M to any program thatneeds it. Unfortunately, there are acouple of catches. The 80286 and laterprocessors can address this memoryonly in a special "protected mode."But to run in protected mode, an AT-

class 286 computer needs softwarewritten to a new standard that isn'tcompatible with any of the old soft-ware programs for the PC.

The 80286 operating mode that

mimics operation of the 8086 is called"real" mode. In real mode, softwarerequires an installable driver to accessextended memory. Without the helpof a driver, ordinary software runningon 286 and later processors can onlynibble from the same megabyte as thefirst -generation 8086.

The 80286 can also address up to 1gigabyte (1G) of virtual memory-approximately a billion bytes. How-ever, virtual memory isn't memory atall. It's yet another convention that re-quires some form of memory manage-ment to be implemented.

The 80386DX (and 80386SX,80386ELS, 386SLC, i486DX, i486SXand variations) was Intel's third try.Intel corrected some problems the80286 had in switching to protectedmode, added some built-in memorymanagement and finally got it right.The 80386 and its i486 fraternal twinaddress memory spaces of up to 4G.They can also access 64 terabytes(64T)-over 64 -trillion bytes of virtualmemory. All memory -managementfeatures supported for the 386 alsoapply to the 486.

The only trouble with all of theyounger children in this family is thatthey maintain compatibility with the8086. This is good because it lets thesame software run on any of thesechips. But it's also bad because itresulted in very little software beingwritten to take full advantage of ad-vances in memory addressing. To doso would shackle the developer's soft-ware to only the latest chips, and theyrepresent the smallest market.

Memory TypesThe memory available to softwarerunning on these Intel processors var-ies with its location in the memoryspace and how it's managed and canbe used. Various types of memory areused by operating system drivers, ap-plications, terminate -and -stay -resi-dent (TSR) pop -ups and memory -management software itself.

Note that there are important dif-ferences between memory and a mem-ory -address space. Although there aremany ways to add memory to compu-ters, a processor's memory -addressspace is fixed. The memory spacesdescribed below are available on allmachines with appropriate proces-sors. However, a given memory space

can't be used unless memory chips arephysically installed there or aremapped there by a memory manager.

Mapping simply means that a logi-cal address (the place where you needmemory) is applied to some corres-ponding piece of physical memory (ac-tual integrated circuits), not necessari-ly at the same physical address. Map-ping is like giving a group of memorychips different names at differenttimes, depending on the job you wantthem to do.

Processors without built-in memo-ry -management circuitry, like the 8086and 80286, are confined to usingmemory at the physical addresseswhere chips are installed. (This han-dicap can be overcome by adding cir-cuitry with an adapter or, for the 286only, by adding external system logicchips.) But in most cases, a memoryaddress refers only to a space, not toa particular chip, one of its cells, norits contents. Real Memory. Other than theawkward "first megabyte," or evenmore ungainly "DOS memory space,"there's no widely -used term for the ag-gregate memory area addressable byDOS. Here, the term "real" memoryis used to refer to this area because the80286, 80386 and i486 are restricted to

0

Conventional

9FFFF

FFFFF

1OFFEE

Upper

HMA

Extended(not available on 8086/8088 equivalents)

Hardware Model 3. Computers with8086, 80286, 80386 or (486 CPU withEMS 3.2, or EMS 4.0 or EEMS boardinstalled.


0

9FFFF

Conventional

FFFFF

Upper

Holes*

Upper

1OFFEE

HMA

Extended

*No physical memory installed

Hardware Model 4. Computers with nochipset, no EMS board and no upperRAM.

it only while running in real mode.80286 and later processors can alsoadd, with some prohibitions, an extra"high -memory area" to their DOS -addressable domains. Conventional DOS Memory. Intelarchitectures and DOS divide realmemory into low and high areas. Thebottom 640K can be called "low"memory, but the term has nothing todo with its binary social status. It's justthe coincidence that memory is num-bered from zero, and this most -impor-tant memory was mapped first.

This memory can also be called"conventional" or "main" memorybecause it's the area originally envi-sioned as all the memory a microcom-puter would ever need for programsand data. That view lasted about aweek, maybe two, but all processorssince have had to honor the miscon-ception for reasons already cited. Upper Memory. Upper memory liesin the area of real memory between640K and the DOS limit of 1M. Thisarea is sometimes referred to as "highmemory," and program code runninghere is said to be "loaded high." Theseterms can lead to confusion with the"high -memory area" (HMA), whichbegins just beyond the upper -memoryaddresses at hexadecimal 100000.) In

the Intel design, the upper -memoryarea is addressable by the processor,but it's intended for ROM -memorychips that contain parts of the operat-ing system and for mapping onto de-vice -controller buffers and other mod-ifications to, or extensions of, the op-erating system. Early machines didn'thave physical memory installed atthese addresses, unless it was a ROM(read-only memory) for firmware orRAM on an adapter card.

The most universal use of uppermemory by an adapter is for videobuffers. That area begins just after the640K low -memory area, at A0000,and can extend as far as BFFFF. Thehighest upper memory, F0000 throughFFFFF, is reserved for addressing thecomputer's basic input/output system(BIOS) that resides in ROM chips. Thearea between these two is reserved formore BIOS memory and the input/output requirements of other adapt-ers. These I/O buffers are a commonsource of conflicts when they overlap.

Overlapping typically occurs whenlocal -area network (LAN) adapters,caching disk controllers and othercards are added to an industry -stand-ard architecture (ISA) personal com-puter. In fact, if too many adapterswith conflicting memory requirementsare added to a system, the discord maynot be resolvable. Microchannel (MC)and extended industry standard archi-tecture (EISA) machines can arbitratethese addresses automatically. (TheEISA bus will also accept ISA adapt-ers that aren't subject to arbitration.)

Wherever an adapter or BIOS isn'tinstalled, this address space remainsunused. And any such real estate thatcan be directly addressed by proces-sors running in real mode is clearly val-uable. As a result, several manage-ment techniques have been developedto make use of it. Most use it to mapresident software and drivers intoRAM. It can also be combined withconventional memory under the prop-er circumstances.

One use for upper memory beganwhen AT -class machines were de-signed with RAM installed in theupper -memory address space. Thesecomputers have system -logic chip sets,frequently from Chips and Technol-ogies, that incorporate a narrow rangeof memory -management abilities.Such systems can switch between theirupper -memory RAM and BIOS ROMs

with a technique called "shadowing."The RAM is, therefore, known asshadow RAM.

To implement shadow RAM, sys-tem BIOS contents and/or video -cardBIOS ROMs are first copied to fastRAM residing at the same address asthe ROMs. The copy is the "shadow,"and the system -logic code switchesmemory lines to it from the ROM.When subsequent calls are made to thefirmware, they're handled by swiftshadow, rather than by the real firm-ware in slow ROM.

A more prevalent use today is tomap upper -memory addresses intoother memory locations at whichRAM is installed. Memory -manage-ment utilities make unused, but ade-quately large, upper -memory addressspaces available to applications. Theycan place 16K frames there for "ex-panded memory," or use them for 4Ksegments known as "upper memoryblocks" (UMBs). Upper Memory Blocks. UMBs arethose parts of upper memory thataren't allocated to system use, such asBIOS ROM and controller buffers. Asthey aren't used by the system, UMBaddresses can be allocated to runningprograms that would otherwise re-quire conventional memory. RAMneedn't be installed at UMB addressesfor them to be used.

One technique is to use these ad-dresses to give programs access tophysical memory at extended -memoryaddresses, but they can sometimes alsoaccess hardware that supports the ex-panded -memory specification (EMS)or physical shadow RAM. Whetherthey can be allocated to XMS, EMS orshadow memory depends on yourmemory manager. It must be able tostore programs in RAM to which theUMB addresses refer.

With available memory, UMBs canbe used to run just about any residentsoftware-installable drivers, systemresources, network re -directors andTSR pop-up programs. Drivers andbuffers are usually loaded high bymodifying statements in DOS's CON-FIG.SYS file, a text file that tells theoperating system how to configureitself in memory. TSRs are oftenloaded high by similar modificationsto DOS's AUTOEXEC.BAT start-upbatch file. Programs then address theUMB or run from it, just like anyother real memory-without bumping


Because needs in the electronicsindustry are constantly changing,MCM Electronics continuallyresearches the market and reacts tothe market's changing needs.

MCM is constantly in touch withnational and internationalmanufacturers to bring bothcommonly used and hard -to -findproducts to its customers.

There are over 17,000 itemsstocked and ready for next daydelivery, including: semiconductors,connectors, audio and VCR partsand accessories, television parts,hardware, test equipment,chemicals, tools and many namebrand items.

MCM ELECTRONICSA PREMIER Company

into video, BIOS or adapter memory.To create this safe world for ap-

plications, though, the memory -man-agement utility itself must vie forupper -memory space, just like anadapter or BIOS chip. Conflicts mustbe resolved before the manager can beinstalled. The trend here is for thememory manager to accomplish de-tection and resolution of these con-flicts automatically.

Not all memory utilities have thisfeature, however, and some conflictsare still undetectable, even by thosemanagers that do. The conflicts thatremain are resolved, whenever possi-ble, by excluding or including regionsof memory with special statements.Many utilities require you to manual-ly edit these statements into the CON -FIG. SYS file. Extended Memory. As mentionedearlier, extended memory lies abovethe 1M address reach of the original8086 processor family, and the 80286and later processors can address atleast 15M of it by switching to a specialprotected operating mode. However,programs must conform to certain cri-teria before they can run in this mode.Most currently don't, unless they use

0

9FFFF

Conventional

FFFFF

Upper

UMB

Upper

1OFFEE

HMA

_

Extended

* -

Remap extended memory to UMBs in uppermemory

Upper memory for Hardware Model 4(only with 80386 or 1486 CPU). Also forHardware Model 3 if EMS board is con-figured as extended memory. Somecomputers can remap replace physi-cal memory in Hardware Model 2 intoextended address space, creating theequivalent of Hardware Model 4.

a "DOS extender." Microsoft's XMSconvention provides extended memo-ry to these applications in the form ofextended -memory blocks (XMBs).

DOS extenders are a type of mem-ory software that manages access toextended memory by switching be-tween protected and real modes. Theyaccess extended memory while in pro-tected mode, switch back to realmode, and then give the requiredpages to the application. However,DOS extenders must be incorporateddirectly into application software.They aren't add-on utilities. If it hasone built into it, your application usesit transparently. If it doesn't have one,you can't add it. Applications that rununder an operating environment, likeWindows or DESQview, can benefitfrom its ability to use built-in DOS -

extender technology to manage mem-ory for its applications.

Programs can also access extendedmemory while in real mode throughuse of drivers. Drivers are simply ad-ditions to the operating system thatprovide a communication protocol be-tween an application and some re-source like extended memory, a net-work or a disk drive.

ALL THE PARTS YOU'LL

Call Today For YourFREE CatalogSubscription!1.800-543-4330FAX 1-513-434-6959 CALL IOU_ FREE

1800.543-4330

Say You Saw It In ComputerCraft ( IR( I.1-. \11.77 I RI. I I \ I III( \I I Ill \ ( kRI)May 1992 / COMPUTERCRAFT / 23

The first extended -memory driverwas one that IBM included with everyoriginal AT: VDISK.SYS, a RAMdisk. Unfortunately, RAM disks aren'tdirectly addressable by applications asis EMS or memory accessed by a DOSextender. Although, they remain asvolatile as the RAM on which they'rebased, RAM disks are accessed usingfile -management conventions.

Other drivers that access extendedmemory include those used to provideXMS and EMS. They're usually pro-vided by operating systems, operatingenvironments or memory -manage-ment utilities. Only the SMART -DRIVE and RAMDRIVE utilities(and variants) and DOS -extended pro-grams can directly use XMS. Manypopular DOS programs use EMS. High Memory Area. The HMA isthe section of extended memory justabove the first megabyte. DOS usual-ly can't address this memory, evenwhen running on an 80386 or laterprocessor. However, an XMS driverlike the HIMEM.SYS bundled withMS DOS 5.0 and Windows 3.0, getsto this "high memory" area by ex-ploiting a feature of 80286 and later

architectures, address line A20, thatnormally goes unused by DOS's 16 -bitarchitecture. Memory utilities withXMS built into them support thisfeature, too. With an XMS driver,programs can directly access nearly anentire 64K of extra memory.

Several bindings hobble the HMA.For example, only one program, oftype COM or SYS, can be run in theHMA; not those with an EXE file ex-tension. The entire file must fit; pro-grams larger than 64K can't be runthere. Moreover, programs that areinterrupt driven-initiated by certainhardware signals-may not run due tothe slight delay that occurs in handlingthe A20 line. Virtual Memory. Virtual memorywas originally developed for main-frames, where it extended addressablecore (main memory) by "paging" itscontents back and forth to mass stor-age (hard disks). This same method isused by Windows' swap files.

In microcomputers, virtual memo-ry takes advantage of non -addressableextended memory, memory on special"expanded -memory" adapters anddisk drives. It's still a technique that

pages data (called a "page") that can'tbe directly addressed by a program toan area (called a "frame" or "pageframe") that can. However, if anadapter or extended memory is usedas the storage area, paging is done bylogically changing addresses in look-up tables, and it's unnecessary tophysically move the data. Expanded Memory (EMS or itsvariant EEMS). The expanded -mem-ory specification (EMS) is a type ofvirtual memory provided by BIOSfirmware or utility software. It's alsosometimes referred to as the LIMstandard for Lotus, Intel and Micro-soft, three of its developers. Like theoriginal virtual memory, EMS pagesdata to addressable memory frames,as required by applications, and pagesdata that's not referenced back to non -addressable storage media as they'rereplaced. Only DOS applications spe-cifically written to use EMS conven-tions can access this memory.

EMS pages can reside on a specialadapter card with its own addressingcircuitry and memory. The card alsohas a BIOS that contains the expand-ed memory manager (EMM) that gives

P -C -B ARTWORK MADE EASY !Create and Revise PCB Art in a Flash

* For IBM's & COMPATIBLES* HERC, CGA, EGA, VGA, SUPER -VGA* AUTO GROUND PLANES* DOT- MATRIX, LASER and PLOTTER ART* GERBER and EXCELLON OUTPUT* CREATE YOUR OWN FILMS with 1XART* LIBRARIES * HELPSCREENS * MENUS* DOWNLOAD DEMOS from 24 hr. BBS!

PCBoards - layout program 99.00PCBoards HP or HI PEN PLOTTER DRIVER 49.00

PCBoards GERBER & EXCELLON Disk 49.00

PCRoute - autorouter 99.00SuperCAD - schematic ...starts at 99.00Demo Pkg. - ( demos of all 3 programs) 10.00

Call or write for more informationPCBoards

2110 14th Ave. South, Birmingham, AL 352051(800)473-PCBS/ (205)933-1122

BBS / FAX (205)933-2954

111111111111111111111

Low Cost CAD Softwarefor the IBM PC and Compatibles

Starting at only $99

PC9 1ne

Layout

*II Design &Simulation

* Easy to use schematic entry program (SuperCAD) for circuit diagrams, only $99. I cludes netlistmg, bill ofmaterials, extensive parts libraries, dot matrix printer output. More parts, HPGL plotter and laser printer outputavailable separately or in enhanced CAD package (SuperCAD.) for only $199.

* Powerful, event -driven digital simulator (SuperSIM) allows you to check logic circuitry quickly before actually

wiring it up. Works directly within the SuperCAD editor from a pulldown menu and displays results in "logicanalyzer' display window. Starting at $99, this is the lowest cost simulator on the market. Support for PALS, alarger library, and a separate interactive logic viewer are available in lull -featured SuperSIM* for only $395.

Library part models include TTL, CMOS and ECL devices.

* Circuit board artwork editor and autorouter programs, starting at $99 each. Produce high duality artwork directlyon dot matrix or laser printers. Separate plotter driver available for $49. You can do both single or double -layerboards with plated through holes. Includes drill hole listing utility. Autoroutes accepts netlists and placementdata directly form the SuperCAD schematic editor.

* All software comes with complete documentation and 30 -day money -back guarantee.

Write or call for further information and free demo disks: \ /MENTAL AUTOMATION,INC.

Mental Automation, Inc.5415 - 136th Place S.E.Bellevue, WA 98006

(206) 641-2141

24CIRCLE NO. 99 ON FREE INFORMATION CARD CIRCLE NO. 78 ON FREE INFORMATION CARD

HMA Workings

If you ignore a couple of mere technicaldetails (such as the four -bit offset thatgives DOS an effective address range of20 bits with a 16 -bit register, and the 16bytes that can't be addressed as a conse-quence), this is how the HMA works.

Memory in the 8086 family is ad-dressed by adding a pair of addressescalled "base" and "displacement." Bycombining a maximum base address(FFFFO, or nearly 1M) with a maximumdisplacement (FFFF, or 64K) it's possi-ble to generate an address (1OFFEF)nearly 64K beyond the 1M pale. How-ever, 8086 through 80286 processors haveonly 20 address lines (AO through AI9).So, an address that exceeds 1M (FFFFF)is wrapped around back into low mem-ory by truncating its high bit. It's as if thebyte that followed 1.141-Tt was 0, not byte100000 (1,048,576 decimal). This kind ofarithmetic may be okay for clocks, butit isn't so good for computer programs.

DOS was designed with this hardwareshortcoming in mind. When the 80386and later processors were designed, theyallowed for additional address lines, butDOS still couldn't use them. XMS driversovercome this deficiency by allowing thesystem to use a 21st address -line, A20.With this addition, even the largest ad-dress that can be generated in DOS's16 -bit registers (1OFFEF) retains its highbit. An operating system like MS-DOS5.0, can use this extra 64K as real mem-ory (that is, without paging or runningin protected mode). By moving someof its own code into the high -memoryarea, DOS can free more conventionalmemory for applications.

applications access to the memory. (Asimilar functionality is also built intosome laptop computers.) Some cardscan optionally configure their mem-ory as extended. Memory managerscan often convert this memory toXMS memory, if required, and use itto create UMBs.

If EMS is emulated by utility soft-ware alone, it must use either extend-ed memory or a hard disk to store itsnon -addressable pages. This hard -disk memory is truly virtual, not realmemory at all. A processor can't ac-cess it directly in any mode, and man-agement utilities can't use it forloading programs high.

The three flavors of EMS are EMS3.2, enhanced EMS (EEMS) and EMS4.0. EMS 4.0 and EEMS are compati-ble with the 3.2 standard and work

with programs that require it. All ver-sions of EMS require a minimum of64K bytes, in four 16K -byte frames,for their buffers.

The earlier EMS 3.2 provides justfour frames for EMS memory and canplace frames only in upper memory.Hardware that features this version ofthe standard is obsolete, but manyboards based on it have been installedin older machines. (And that's wherethey are today.)

EMS 4.0 incorporates changes in-troduced by EEMS and has supersed-ed it. It allows up to 6416K -byte EMSframes and can place them anywherein the first megabyte of DOS -address-able memory. EMS 4.0 is the versionrequired by most memory managersthat work with EMS adapters. How-ever, some utilities, like the Quarter-deck Expanded Memory Manager(QEMM), are also compatible withEMS 3.2 and/or EEMS adapters.(Quarterdeck's QRAM 286 managercan also work with EEMS adapters.)

Memory ManagersMemory managers usually provide abundle of memory services throughXMS and EMS drivers. Certainly, allof those researched for this article pro-vide management of UMBs. They usethem to load TSRs and drivers into thespace between the video buffer endingat BFFFF (or the VGA BIOS endingat C7FFF) and the beginning of sys-tem BIOS at F0000.

Most utilities provide EMS buffersfor programs that require them, manyprovide access to the HMA, and somecan load extra DOS 3.x system buffershigh, as well. Note, however, that notall of those that provide EMS can pro-vide it for Windows' real and standardmodes. The better managers alsomove most of their own code out ofthe first megabyte of memory. (It's animportant feature because the mem-ory addresses available in real modeare all too quickly exhausted-evenwith the use of EMS.) Most provideshadow RAM, in extended memory,for machines that don't already haveshadow RAM installed at upper -mem-ory addresses.

With a single exception, memorymanagers load programs high by mod-ifying the CONFIG.SYS and/orAUTOEXEC.BAT files. Nearly allmake the required changes automati-

cally for 386 and 486 computers but re-quire manual editing either for cus-tomization or if they provide manage-ment on 286 machines. And let's faceit: Many systems will work with anyof the automatic -installation systems,but others are going to be a problem,no matter what memory manager youselect. A lot depends on the adaptersyou have and the software you run.

Without exception, every memorymanager, no matter how automated,has a method for including and ex-cluding regions of memory from itsmanipulations. The nearly catholicmethod, which prevents a managerfrom using regions in use by undetect-able processes or hardware is to use anEXCLUDE parameter on the commandline. For example, IBM token -ringadapters have memory that's difficultto detect because it's activated onlywhen required. To exclude a regionfrom D0000 to D4000 with MS-DOS5's EMM386.SYS, the command:

DEVICE = EMM386.EXE X = D000-0400

would be added to the CONFIG.SYSfile. Note the use of paragraph ad-dresses and the terse form of thecommand.

Managers can increase availableUMB space by adding unused frag-ments of upper memory as small as4K-including those in the dedicatedBIOS area above F0000. UnusedBIOS areas can include code used onlyduring system start-up, such as thepower -on self test (POST) and thesystem setup. Regrettably, these tech-niques are dependent on very intimateknowledge of (and work only with) alimited number of BIOS chips.They're not available for all machines.A complementary INCLUDE statementtypically recovers omitted areas. Toensure recovery of a 32K video rangebeginning at B8000, append MS-DOS5's equivalent version of INCLUDE toour earlier statement:

DEVICE = EMM386.EXE X = D000 -D400I = B800-BFFF

DOS 5's terse commands aren't com-mon. EXCLUDE and INCLUDE are theparameters for nearly all memory -management utilities. However,QEMM allows use of both verboseforms (EXCLUDE and INCLUDE) andterse forms X and I) for the great ma-jority of its commands. An equivalent


0

9FFFF

Conventional

FFFFF

Upper

UMB

Upper

1OFFEE

HMA

Extended

Upper memory allocation for Hard-ware Models 1 and 2 converts physicalRAM to UMB.

statement for QEMM-386 could bewritten in a form similar to the one forMS-DOS as follows:

DEVICE = QEMM386.SYS EXCLUDE= D000 -D400 INCLUDE x B800-BFFF

Memory managers are constantlyevolving to provide more services be-cause many of their basic features arenow also part of the principal small -computer operating systems: MS-DOS and DR DOS. Utilities can con-tinue to compete only by aggressivelyproviding more available memorythan do more -conservative operatingsystems. Thus, nearly all of today'smanagers offer special features thatdifferentiate them from their competi-tion. About the only familiar memo-ry -management feature that still isn'toffered by anyone is the ability toremove TSRs or drivers from memo-ry. A number of TSR managers pro-vide this in conventional memory, andHelix's HEADROOM works withNETROOMin upper memory as well.

The more -aggressive a manager'sapproach, however, the more familiarit must be with specific hardware andsoftware in its environments, and themore prone it will be to compatibilityconflicts. Even among operating sys-tems, the more -aggressive DR DOS ismore likely to feel the constraints of

compatibility than is MS-DOS, whichcan provide less available memory onsome machines.

As an example, DOS isn't allowedto load its tables and buffers into EMSmemory while using V Communica-tions' Memory Commander. Thismeans that VDISK, FASTOPEN and theBUFFERS commands mustn't employtheir /X parameter. (MC can load allthis, plus executable code, high in-stead.) The same is true for QEMMwhen using some versions of DOS 4.x.More examples follow.

In addition to EMS and XMS ser-vices, memory managers can provideapplications with access to additionalphysical memory. QMAPS, for exam-ple, can recognize a large number ofsystem -logic chip sets and, thus, is ableto detect many AT -type machines thathave dynamic RAM chips (DRAM)installed in the upper -memory area.QMAPS recovers the part of thismemory not used for shadowing tostore code or data that can be accessedin the UMB address space. 386MAXand QEMM can do the same withCompaq Top Memory.

It isn't possible to detect every in-stance where the technique can beused, but unless a computer can phys-ically switch this DRAM into theextended -memory -address space,managers without this ability let muchof it go to waste.

A scheme that has become com-monplace in the latest generation ofmemory utilities is "backfilling" con-ventional memory with unused ad-dresses from the video buffer.Monochrome adapters (and EGA andVGA monochrome modes) don't re-quire the first 64K of video addresses,from A0000 to AFFFF, for their buf-fers. Instead, these addresses can beadded to a computer's contiguousconventional space, for a total of704K. For a CGA adapter, or for EGAor VGA color -text modes, the videobuffer starts at address B8000.

Many managers make available the96K from A0000 to B7FFF for con-tiguous conventional memory.Therefore, CGA-graphics or colortext-CGA, EGA or VGA applica-tions-can have a total of 736K. Fur-thermore, there are different backfillstrategies. QEMM-386, for example,normally requires an EGA or VGAadapter and adds memory, dependingon monitor type. It adds memory only

if it exists as RAM at those addresses.DR DOS does this, too, but it can alsobackfill monochrome and CGA adapt-ers by mapping to other memory.(This eliminates the risk of crashes,because they can't be switched to thewrong modes.)

There's one potential drawback tobackfilling from EGA or VGA. DRDOS, and some other managers, re-quire you to run a utility before youswitch an application back to graph-ics mode on an EGA or VGA adapter.In some cases, if you forget and try torun a color -graphics program withoutrerunning the utility, the system is like-ly to crash.

There are also a couple of 32K re-gions in EGA- and VGA -adapter buf-fers you may be able to recover forUMB space. The area from B0000 toB7FFF isn't used for color operationof these adapters. The area fromB8000 to BFFFF isn't used duringmonochrome operation. Either regioncan be recovered when it isn't beingemployed as a buffer. Some utilitiesalternately use the region at B0000 torelocate the 32K VGA BIOS from

0

9FFFF

Conventional

-- _

EMS 3.2/4/0 EEMS

Conventional

- - - -

FFFFF

Upper

-- - -Upper EMS 4.0/EEMS

Upper

1OFFEE HMA

Extended

EMS memory allocation for HardwareModel 3. Memory manager cannot pro-vide EMS service when provided by acard. Whenever a memory manager isavailable, memory on an EMS cardshould be configured as extendedmemory, if possible. Use the managerto provide all the memory types fromextended.


0

Conventional

EMS 3.2/4.0 EEMS

9FFFFConventional

Upper

EMS 4.0 EEMS

FFFFFUpper

1OFFEE 1-IMA

Extended

- - - - - - - - - -- - - - - - -Extended

Storage

Pages

EMS memory for Hardware Models 1 and 2. Also for Hardware Model 3 if EMSboard is configured as extended memory, and for Hardware Model 4 with 80386or i486 CPU.

C0000. Other utilities require you toconfigure these areas yourself.

Another trick is to free up frag-mented areas of upper memory for useas conventional memory. The ap-proach Memory Commander uses isto compress active areas, such asUMBs and the video buffer, as far aspossible towards the top of the upper -memory space. Unused slack is allo-cated downward to main memory.This method provides more programmemory than any other. However,there's a tradeoff.

Any program that writes directly tothe physical address of video memorymust either use a standard method(INT 10, function FE), developed byIBM and used by both V Communica-tions (the company's relocated screeninterface specification, RSIS) andQuarterdeck (for DESQview), or paya performance penalty while MemoryCommander translates the addressesfor every video -buffer access. (A pro-gram that uses DOS -service or BIOScalls for screen operations doesn't re-quire translations and pays no penal-ty.) Nevertheless, a performance hit of10% during video access (the com-pany's performance claim) may bequite tolerable when the alternative isthe inability to fit a program intoavailable memory.

NETROOM has an even moreradical scheme that can add as muchas 576K of EMS memory to a com-plete, and separate, conventional -memory space, and up to 224K ofUMB space. In other words, you canmove up to 576K of TSRs and driversout of conventional memory withouttouching upper memory. Helix con-tends that its NETSWAP4 utility uses"virtual machine" (VM) technologysimilar to that used by Windows, andthat its VM even allows Windows twoDOS sessions to communicate witheach other. Using this technology, it'spossible to put a network redirector in-to one session and a DOS applicationthat uses it in another. Nothing elsegives Windows this ability, and it'salmost scary to think of so many elec-trons running wild in there all at once.

There's a disadvantage to theabove, naturally. You can't attach anddetach network resources from theWindows control panel. Performanceis also degraded-no more than 30%on throughput from a busy server andless than 10% on a workstation, ac-cording to Helix president Mike Spilo.A smaller VM can alternately beplaced in upper memory, and net-works will run faster loaded there.

Memory managers also offer mem-ory -related services. one of which is

optional "instancing" of TSR pro-grams or drivers for use with Windows3.0. Windows 3.0 -aware TSRs anddrivers-the MS Mouse driver, for ex-ample-automatically provide in-stancing for each of the VMs Win-dows uses to run DOS applications.Every DOS application has its owncopy. The memory manager providesinstancing for programs that aren'tWindows -aware. (Never use it with adisk cache, though, because you haveonly one real disk surface.)

Another routine extra is the addi-tion of emulated shadow RAM formachines that don't have DRAM in-stalled at the upper -memory ad-dresses. The memory utility providesthe shadow in extended memory that'smapped to the ROM addresses. Thismethod can offer an advantage overa built-in manager if a computer op-tionally allows its physical shadowRAM to be re -mapped as extendedmemory. In this case, the memorymanager still can use the RAM forshadowing, but it can also recoverunused areas for inclusion in itsextended -memory pool.

286 Versus 386 MemoryThere are actually two classes ofmemory managers: those for 386 -basedsystems and those for systems basedon the 286. As already noted, the twoprocessor families have different ar-chitectures and, so, require differentstrategies to provide memory services.The most important difference is that386 processors have memory -manage-ment circuitry built into them that autility can use for addressing and map-ping. It's almost certain that you'll beable to get EMS and XMS memory foryour 386 machines through the expe-diency of an inexpensive memory -management utility. This isn't neces-sarily so for 286 systems.

Because the 286 processor doesn'thave built-in memory -managementcircuits, memory management mustbe provided by external chips. Themissing features are sometimes pro-vided by the support chips that 286 ATmanufacturers use to simplify build-ing their machines. These system -logicchips combine many of the originalPC's separate circuits, such as thememory controller, direct -memoryaccess (DMA) controller, interruptcontroller, universal asynchronous


Earn Your B.S. Degreein

ELECTRONICSor

COMPUTERS

By Studying at HomeGrantham College of Engineering,

now in our 42nd year, is highly ex-perienced in "distance education"-teaching by correspondence-throughprinted materials, computer materials,fax, and phone.

No commuting to class. Study atyour own pace, while continuing onyour present job. Learn from easy -to -understand but complete and thoroughlesson materials, with additional helpfrom our instructors.

Our Computer B.S. Degree Pro-gram includes courses in BASIC,PASCAL and C languages - as well asAssembly Language, MS DOS, CADD,Robotics, and much more.

Our Electronics B.S. Degree Pro-gram includes courses in Solid -StateCircuit Analysis and Design, ControlSystems, Analog/ Digital Communica-tions, Microwave Engr, and much more.

An important part of being pre-pared to move up is holding the rightcollege degree, and the absolutely neces-sary part is knowing your field.Grantham can help you both ways-to learn more and to earn your degreein the process.

Write or phone for our freecatalog. Toll free, 1-800-955-2527, orsee mailing address below.

Accredited bythe Accrediting Commission of the

National Home Study Council

GRANTHAMCollege of Engineering

Grantham College RoadSlidell, LA 70460

receiver/transmitter (UART) and par-allel input/output (PIO) circuits. Butnot all chip sets offer memory -man-agement support, and those that do,don't offer the required services in thesame way.

ATs built from chip sets that havesupport, may or may not work with a286 memory -management productlike Quarterdeck's QRAM, dependingon whether software was written forthat machine's particular chips. For-tunately, most 286 products also workin systems that have an EMS 4.0

adapter card installed in them.There are also utilities that work

with their own proprietary hardware.Just about all 286 machines work withproducts like the All Charge Card.However, there's a drawback to thisapproach too-high cost. While theseproducts work well, the price of386SX upgrades and replacementmotherboards has fallen to the pointwhere hardware -based memory man-agers are no longer attractive at a $200to $400 price point.

More and more, the market forhardware solutions shrinks to includejust those premium machines whereupgrade costs are still high. And evenat the high end, products like theKingston Technologies SX/Now! canupgrade a 286 -based PS/2 (Models50,60, AT and XT 286) with a 20 -MHz386SX processor. It has a fairly sim-ple plug-in installation that doesn't re-quire removal of the original mother-board, and it gives both memory man-agement and a faster 32 -bit processorfor a cost of $475.

Besides the standards used to pro-vide memory services, programs thataccess memory in protected mode mayconform to one or more standardsused to coordinate their activities withhardware, firmware, other programs,environments and operating systems.The most important of these are theDOS protected -mode interface(DPMI), Virtual Control Program In-terface (VCPI) and Virtual DMA Ser-vices (VDS). The protocols that DPMIand VCPI provide are required forprotected -mode programs like mem-ory managers and Autodesk's Auto -CAD to coexist with each other.DESQview, for example, cooper-

ates with memory managers throughVCPI, a protocol that allows a DOS -extended program to run when loadedafter an expanded -memory manager.

Address Calculation

Memory managers have restrictions onwhere they can place UMBs and EMSpage frames. UMBs must begin on 4Kboundaries. Page frames require a 16Kboundary. ROM relocation has similarprerequisites. Fortunately, the necessaryhexadecimal calculation requires nomath, just the ability to recognize onlyfive hexadecimal digits. The digit posi-tions in a hexadecimal address have thefollowing values:

Digit ValuePosition In Bytes

4 64K3 4K2 1261 16

The highest -order digit in any address(Digit 4) represents a 64K boundary. Thenext lower -order digit (Digit 3) representsa 4K boundary. The other positions willalways be 0 for any 4K or 16K boundary.

For example, if "X" stands for anyhexadecimal digit, the following numberalways falls on a 4K boundary: XX000.Numbers with any value (X) in the high-est digit and a 0, 4, 8 or C (which equalsthe decimal number 12) in the next posi-tion are on a 16K boundary. Thesenumbers all look like X00000, X4000,X8000 or XC000.

Of course, the alternative forms of no-tation explained earlier can also be used.In this case, a 4K boundary has the formXX00 or XX00:0000. 16K boundariesare either X000, X400, X800 and XCOOor X000:0000, X400:0000, X800:0000and XC00:0000.

What follows is the complete table of16K boundaries in upper memory, as rep-resented in the abbreviated paragraphform usually required by memorymanagers:

A000 B000 B000 D000 E000 F000A400 B400 B400 D400 E400 F400A800 B800 B800 D800 E800 F800ACOO BBOO BC00 DC00 ECOO FC00

Windows, in contrast, supportsDPMI in the virtual machines it usesto run enhanced -mode DOS sessions.Without DPMI, DOS extended pro-grams have to switch to real modewhenever they want a DOS service(such as a mouse or driver), use the ser-vice and then switch back. WithDPMI, applications make a call to aDPMI host that satisfies these require-ments with its translation services.(DPMI host services are available


Video Map

The following represents the regions used by standard videomodes on PCs and ATs. Unfortunately, one of the hazards ofmemory management is that software doesn't always use themode you expect. For example, upon detecting a VGA adapter,some programs ignore a monochrome monitor and use the colorregion at B8000. This isn't normally a problem for the VGAadapter, but it's disastrous if a UMB has been mapped at B8000.

Address Standard Uses and Buffer Locations00000 Beginning of conventional memory9FFFF End of conventional memoryA0000 640K boundary

Beginning of upper memoryVGA -Adapter Data

Beginning of video buffer on VGA adaptersBeginning of region used in all VGA graphics modesBeginning of region free in VGA color -text modes

CGA-Adapter DataBeginning of vacant RAM region on CGA adapters

Monochrome -Adapter DataBeginning of vacant RAM region on monochrome

adaptersAFFFFVGA -Adapter Data

End of VGA monochrome -graphics regionEnd of standard VGA color -graphics region

B0000VGA -Adapter Data

Beginning of first special 32K VGA regionused by VGA monochrome -text modesfree in standard VGA color modesused by some super -VGA adapters in high -resolutionmodes

Monochrome -Adapter DataBeginning of video buffer on monochrome adapters

BOFFFMonochrome -Adapter Data

End of video buffer on monochrome adapters

BFFFFVGA -Adapter Data

End of first special 32K VGA regionEnd of region free in VGA color -text modesEnd of regions used in VGA monochrome -text modes

B8000VGA -Adapter Data

Beginning of region used in VGA color -text modesBeginning of second special 32K VGA region free in allVGA monochrome modes

CGA-Adapter DataBeginning of video buffer on CGA adapters

BFFFFCGA-Adapter Data

End of video buffer on CGA adaptersBFFFFVGA -Adapter Data

End of VGA color -text regionEnd of some super -VGA high -resolution graphics

regionsEnd of all video buffers

C0000 End of 32K VGA BIOS (ROM) regionBeginning of region used for UMBsBeginning of region used for miscellaneous adapter

RAMBeginning of region used for miscellaneous adapter

ROM (regions used by networks interface cards[NICs], fax boards, etc.)

E0000 Beginning of area sometimes used by built-in shadowRAM to relocate video BIOS

Beginning of the system BIOS ROM

Notes: (1) Standard VGA and EGA video share the same starting ad-dresses; (2) Size differences between EGA and VGA regions are insignifi-cant to creation of UMBs and EMS frames; (3) Standard monochromeaddresses are also Hercules addresses; (4) The last byte of a 64K regionhas an FFFF address ending; (5) The last byte of a 4K region has an FFFaddress ending.

from OS/2, as well as Windows.)Lotus 1-2-3 Version 3.1, in turn, re-quires memory managers to coordi-nate with it through either VCPI orDPMI.

VDS is a specification that coordi-nates direct -memory access (DMA)device drivers and the memory man-ager so that they work with the sameaddresses. It ensures that DMA chan-nels are correctly handled when oper-ated in protected mode.

Address ConventionsMemory addresses in this article aregiven in decimal kilobyte figures (suchas, 640K) or hexadecimal bytes (suchas, A0000). There are other standardforms of notation you may encounter,often unexplained, in your documen-tation. An address like A0000 can be

written as A000 or A000:0000, allreferring to the same location. Ineither of the latter cases, A000represents the number of 16 -byteparagraphs of memory, not bytes.

Multiplying A000 by the size of aparagraph, hexadecimal 10 (decimal16), gives an address of A0000, the ad-dress after the 640K of conventionalmemory (00000 to 9FFFF). However,A000 can also represent bytes, inwhich case, it refers to the address im-mediately following the first 40K,which runs from 0000 to 9FFF. Payclose attention to the convention usedin the documentation that accompa-nies all hardware and software.

Configuring a memory manager foran AT -class computer often requiresknowing where certain boundariesare. This requires knowing a few sim-ple tricks (see Address Calculation

box). If you also commit some of thestandard boundary addresses to yourown memory, you'll make manualchanges and troubleshoot with moreconfidence.

Tune in next month for our discus-sions on MS-DOS 5.0 and DR DOS6.0 and reviews of memory -manage-ment products that enhance the utili-ty of these two operating systems.

Yacco


Upgrading By Nick Goss

A Tower of an EnclosurePart 4

Construction, checking out the CYANCE BusExpander system and final installation

Last month, we detailed how theCYANCE Bus Expander can add

six more expansion slots to an existingPC/compatible computer. We fo-cused on how the circuitry works.Now we get on with how to wire thevarious elements that make up thesystem and we step you throughcheckout to make sure everything isrunning smoothly. Then it's on to in-stallation of the system in theCYANCE enclosure and, finally, con-necting together all the elements.

ConstructionWhen building the CYANCE Bus Ex-pander, it's important that you takeyour time. Don't expect to completethe project in an evening or two. Keepin mind that in a complex system likethis, a single solder bridge can preventthe entire system from operating. Sobe very careful when soldering com-ponents into place. Use only enoughsolder to assure good electrical andmechanical connections. If you do ac-cidentally create a solder bridge, clearit immediately.

Circuit layout is critical in this BusExpander project. Therefore, I highlyrecommend that you use the actual-

size printed -circuit artwork providedin Fig. 7 if you make your own boards.If you do make your own double -sidedprinted circuit fabrication, see the"Making Double -Sided Boards" boxelsewhere in this article for guidance.You can also make single -sided boardsand use the component -side artworkfor installing jumper wires in place ofthe conductor patterns shown. Alter-natively, you can purchase ready -to -wire boards from the source given inthe Note at the end of the Parts List.

Begin assembling your Bus Expand-er by wiring the Master Control Card,

using the wiring guide shown in Fig.8. I prefer to solder the ICs directly in-to the board. However, you mightwant to use sockets. If so, it's impor-tant that you use the barrel -pin typesocket that lets you solder the pins ontop of the board.

Once the ICs or sockets are in place,mount PI and P2, making sure to po-sition them for component -side sol-dering access if you're using a home -fabricated board. Then mount andsolder into place the capacitors, mak-ing sure you polarize them as shown.

Note that resistors and jumpers arearranged side by side near 40 -pin con-trol cable header socket PI. When youinstall and solder into place these

items, be particularly careful to avoidsolder bridges. Next install the feed-throughs, using either cut-off resistorleads or No. 22 solid hookup wire,soldering them to the copper pads onboth sides of the board.

As you work on alternate sides ofthe board, be on the lookout forbreaks and bridges in the coppertraces. If you locate any bridges, clearthem with a sharp hobby knife. Repairbreaks with solder if they're very fineand with bare hookup wire and solderif they're larger.

Next, jumper the pins 1 and 20 di-rection control lines as indicated.

Mount 40 -pin header socket P1 and36 -pin male strip connector P2 in their


1818118888881888818 .1

II l!t!'20. 19cc,1:4

Di

000

0 0- 0-0 0-0 0-0j000

0 1:1

ggico 0

88.80001000000000000000010101000000010

000000000000000000

0000000000000000000000000000000000000000

00000000000000000000

00

(A)

0 0 0 0 0 0 0 0

00 0

1_00Qo0000000

000

000.00

0 0 0000000

0 0;12.0g

000000000

o 00000000

0 0 0 0 0 0 0 0 ° ° ° ° °-°o-o0 0 0 0 0 0

0 0 0 0 0 0 0 0

000000000

0

0 0 0

0 . 0

1111111111111111110'101t1111111111

c-)>-cc

m

O

O

Qa0

Fig. 7. Actual -size printed -circuit artwork for (A) Master Control Card; (B) Data Master Card; (C) Data Slave Card; and(D) Bus Card.


0

Dit

8RJ938Y3 .2.0 1111116: ;11111%%*

Orli("17'fi

11I- i-L7 I

0 0

°

V .011111 0

8.2 USseer

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0

0 0 0 0 0 0 0 00

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 . 0 0 0 0 0 0 0 0 0 00

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0-00 0 0 0 0 0 00 0 00

0 0 0 0 0 0 0 0 0 pA 0 0 0 0 0 00 Ctionsm()

A 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 1

n ee0000000000000c000ci0000000000000000

O

Occo-cc

Q

rro

QO

(B)

respective locations. Position P2 togive soldering access on top of theboard. Configure the MEMW, MEMR,low and IOR lines for Master mode.

Wire the Slave Control Card next,following the same procedure detailedabove. However, make sure you con-

figure this card as a Slave. Again, useFig. 8 as a wiring guide.

Construction of the Data Masterand Slave Cards is similar to that forthe Master Control Card and is de-tailed in Fig. 9. Begin by placing thedamping resistors in all shunt loca-

tions, as indicated. Mount the capa-citors and install the through -boardvia wires. Solder 40 -pin header socketP1 into place. Then mount the ICs,directly or via sockets.

Mount SIP resistor pack R21. Placethe small dot at one end of it in the


8.2 U3A

8171,1111111(1

11111111

0

See/

1° 1)'o °

116

000

ID

6Tn

a

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0O

0 0 0 0 0 0 0 0

0

0 0 0 0 0 0 0 0 0

i0 0 0 0 0 0 0 0

a

0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0

A 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0

A 0 0 0 0 0 0 0 0

O 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0

000000

0

0

n 0

0 0 0 0 0 0 0 0

0 0 0 0 0 0 :

0 0 0 0 0 0 0 : 0

0 0 0 0 0 0 . 0 0 0 0 0 0 0 0 :

C.,...=1.mmC)

0

00000000n0000ci0000000000000000000000cioaci000

(C)

square pad + 5 -volt hole. Mount DIand D2, and finish up by mounting P2on the bottom side of the card.

You wire the Data Slave Card exact-ly the same as you did the Data Mas-ter Card, except for the dampingresistors and jumpers. Use Fig. 9 as a

guide. Also, notice that the value ofSIP resistor pack R21 changes to 470ohms and extra 470 -ohm R10 discreteresistor installs next to it.

The Bus Card is the backbone of theBus Expander. If you're using the sin-gle -sided board option, first be sure to

install No. 22 wire jumpers in place ofthe traces for the component side ofthe board (see Fig. 10 for wiring de-tails). Then install and solder intoplace the 62 -contact bus card -edgeconnectors flush with the top surfaceof the card.


z0

00

0Se

et8R

J513

8Y3

0000

0000

0000

0000

0000

0000

0000

000

0000

0000

0000

0000

0000

0000

0000

000

007-

4C

I,C

omm

e

0000

0000

0000

0000

0000

0000

0000

000

ow00

0000

0000

0000

0000

0000

0000

0000

000

(:1:

1

r7==.14

Cum0

ping

0000

0000

0000

0000

0000

0000

0000

000

0°00

0000

0000

0000

0000

0000

0000

0000

0cl

°C

omon

emm

ee

r7mm4

N4

1.m...

g

000000000000000000000000000000

0°

0000000000000000000000000000000

0°

iii=:

ciiiic

014

()C

10

0000

0000

0000

0000

0000

0000

0000

t0 w

al.C

:21

000

0000

0000

0000

0000

0000

0000

0000

000

{:m

onom

mie

r=4

40.....0

0000000000000000000000000000r7771

0000000000000000000000000000000

00

mil0

00

N4

0.1.

000

0000

0000

0000

0000

0000

0000

0007

7100

0000

0000

0000

0000

0000

0000

0000

0 00

0es

....4

risrm.14

CONIC 00

0000

0000

0000

0000

0000

0000

0orm

orm

m01

0000

0000

0000

0000

0000

000n

nnot

l000

0°00

0000

000

0

0

0 0

0 0

0 0

0 0

0 0

0 0

0

(r11.1)

2U8 30WAY3

00

00

Install the power connector andsupply -line capacitors as shown. If youplan to mount the Bus Card inside theCYANCE enclosure, use the mount-ing holes, screws and spacers. How-ever, if you plan to use the Bus Cardon a benchtop, press five or six self -stick square rubber feet on the bottomof the card to permit the bus to free -stand on your bench.

Two 40 -conductor ribbon cableswith 40 -pin IC headers at each end arerequired. Make your cables only aslong as needed for your setup, but notlonger than 10 feet. Keep in mind thatthe longer the cable, the greater thechance of bus signal distortion at highclock speeds. Also, make sure the ca-bles are the same length.

Use a vise or connector crimpingtool to secure the IDC (insulation -displacement connector) header onthe cable. If you use a vise, place apiece of metal, plastic, or wood thatfits between the two rows of pins onthe header to protect the pins as youclamp down. Your protector blockshould be about 0.100" taller than theheader pins to protect them as the visesnaps the rear shell of the connectorinto place.

Your ribbon cable will probablyhave a colored stripe along one side toindicate line 1. This conductor willreally go to pin 2 if you check, but itwon't matter, as long as the color stripis at the correct end of the header.

Install the first header so that thered strip is on the left side of it, withthe header pins facing away from you,and pin 1 in the lower -left corner.

With the first header installed onone end of the cable, hold the cableends up together so that the cablehangs down and forms a U shape. In-stall the second connector in the samemanner as the first. When you'redone, set the cable on a table so thatthe header on your left has its pins fac-ing away from you. Now, with the ca-ble stretched out flat on the table, thepins of the header on your right shouldbe facing you.

Make both cables in the same man-ner. When you plug the headers in thesockets on the Control and DataCards, you can put a 90 ° fold in thecable so that it runs out the front of theassembly.

With your Bus Expander complet-ed, it's a good idea to go over every-thing one more time. Check for prop-

er wiring (components installed in theproper locations and properly polar-ized or oriented), missed solder con-nections, etc. Make absolutely certainthat your work is correct. Rememberthat you are getting ready to plug theBus Expander system into a slot onyour computer's motherboard andmistakes can be costly.

CheckoutTo properly check your CYANCEBus Expander, you need an oscillo-scope. Though meters are okay formaking static measurements, youmust be able to view the waveforms onthe bus. For this, a scope is the only

practical instrument to use when view-ing the activity on individual contactson both buses.

Begin checkout by connecting theCYANCE Bus Card to the power sup-ply in the CYANCE enclosure. UseFig. 1 from last month to verify allpinouts for the buses. Then use thescope or a DMM to check the voltageoutputs of the power supply.

When you're satisfied with the con-nections, apply power to theCYANCE Bus Card without any oth-er cards plugged into its bus connec-tors. Now check the various powerpins to make sure the proper voltagesappear at each pin in each connector.If everything isn't in order, power

PARTS LIST

Master Control CardSemiconductorsUl thru U6 -74S240 bufferCapacitorsC1 thru C7 -10-µF, 16 -volt electrolyticResistors ('/ -watt, 5% tolerance)RI thru R13-100 ohmsMiscellaneousPI -40 pin DIP IC socketP2 -36 -pin male single -row connector

Printed -circuit board; IC sockets (seetext); solder; etc.

Slave Control CardSemiconductorsUl thru U6 -74S240 bufferCapacitorsCl thru C7 -10-g, 16 -volt electrolyticResistors (1/4 -watt, 5% tolerance)RI thru R9-100 ohmsMiscellaneousP1-40 pin DIP IC socketP2 -36 -pin male single -row connector


Data Master CardSemiconductorsU I ,U2,U3,U6-74S240 bufferU4,U5-74S38 quad two -input NAND

gate with open collectorsU7 -74S00 quad two -input NAND gateDI ,D2 -1N4148 switching diodeCapacitorsCl thru C6 -10-g, 16 -volt electrolyticResistors (1/4 -watt, 5% tolerance)RI thru R20,R22 thru R29-100 ohmsR2 1 -2,200 -ohm SIP packMiscellaneousP1 -40 -pin DIP IC socketP2 -36 -pin female single -row connector


Data Slave CardSemiconductorsUl ,U2, U3 ,U6 -74S240 bufferU4,U5-74S38 quad two -input NAND

gate with open collectorsU7 -74S00 quad two -input NAND gateCapacitorsCI thru C6 -10-g, 16 -volt electrolyticResistors ('-watt, 5% tolerance)RI thru R8-100 ohmsR10-470 ohmsR9 -470 -ohm SIP resistor packMiscellaneousP1 -40 -pin DIP IC socketP2 -36 -pin female single -row connector


Bus CardCapacitorsCl thru C28 -10 -µF,16 -volt electrolytic

with radial leadsC29 -47-µF, 16 -volt electrolytic with

radial leadsC30 -1-µF, 16 -volt electrolytic with

radial leadsC31 thru C37 -10-g, 16 volt electrolytic

with axial leads

MiscellaneousP I thru P8 -62 -pin card edge connector

with contacts on 0.100" centersP9 -12 -pin male PC power connector

Printed -circuit board; solder; etc.Note: The following items are available from

U.S. Cyberlab, Inc., Rte. 2, Box 284, CyberRd., West Fork, AR 72774 (tel.: 1-501839-8293 or 1-800-232-9865 voice only): Allfive double -sided pc -board kit with holesnot plated -through, $79.95; completeCYANCE Bus Expander electronic kit, in-cluding pc boards, $169.95. Add $4.95P&H. Akansas residents, please add 6%sales tax. MasterCard and Visa welcome.


NM)

auluo

O

Z2

La

>Q 0.10.0- 01 CI- CI- 0-0-1:1-11-7'm-,,, 2.,,,,,,,m 7. 1.-,m 7777.

c ,,crI-iri

0cerecece,-tee,cen,,w0

D_ttt1- 0-0-0-11.0- 0- Ct. 0 -NO-,z

z

,n<z -0.1rn.4.MMMMMLO,OMN.McOch----MCti:CCrCe,-)--5,-,rter-AY,CCI:CMCCCr -3

N0.-NI.,..1.111t.0,C00,0-fl_

.-,11.1SICI(01.--00 Cr, N

< NtO

toI Li,NIcsi",

wi

ceo4

mo)

vIto

- 00

0

NM

Fig. 8. Master wiring guide for Master/Slave Control Cards.

down and correct the problem. Do notproceed until you're certain every-thing checks out okay.

Next, connect a clip lead with a4,700 -ohm current -limiting resistor tothe + 5 -volt terminal of the powerconnector to make a signal injectorthat you'll use to check the other pinsacross the bus.

Using Fig. 1 as a guide, work yourway up and down the contacts of theslot 8 connector. Apply + 5 voltsthrough the 4,700 -ohm resistor whilechecking for + 5 volts along the entirelength of the bus. Your scope or metershould indicate about 4.5 volts. If youfind that this voltage is grounded,shorted to another pin, or absent,power down and correct the problem.

If you encounter a location wherethe measured potential is down about1.5 to 3 volts (don't be fooled by thevarious power -supply pins), the lowreading probably indicates a resistiveshort caused by excessive flux in thesolder at that connection. The solutionis to clean your CYANCE Bus Cardwith a good -quality solvent.

At each contact location, check thecontacts immediately adjacent to it aswell. If a copper -trace bridge or solderbridge is shorting two or more pins to-gether, clear it now.

With the Bus Card in front of youon a nonconductive surface and theCYANCE enclosure's power supplyshut down, connect the two together.Make absolutely certain you make thisconnection properly and that no othercards are plugged into the slots on theBus Card. Plug the Master ControlCard into slot 1. With the power -sup-ply connector at the far end of the BusCard (away from you), the MasterControl Card should have its foil sidetoward you.

Warning: Because the Bus Card isout in the open during this procedure,it's very easy to lose track of whichedge is the front of it. Plugging in aperipheral card backwards will morethan likely destroy it in an instant! Sokeep double-checking yourself on or-ientation! I put a small sticker on thefront of my Bus Card that identifiesit as such. You should do the same.

With the Master Control Card inplace, power up the supply in theCYANCE enclosure while monitoringthe + 5 -volt power bus. If the mea-sured potential comes up to about 4.5volts, everything is okay. If you


should observe a low voltage or novoltage at all, power down and re-check everything.

Once you're sure everything isokay, power up again. Checkout ofthe Master Control Card is relativelyunstructured because it would take awritten procedure about the size ofthis entire magazine to do it right.

Because the 74S240 buffer ICs areinverters, you have only to use agrounded clip lead to check each in-put. Place your scope or DMM on anyparticular output pin of the buffer ICunder test. (Be sure to note which"bank" is enabled by the directioncontrol voltage on pins 1 and 19. Thisselects which pins are inputs and whichare outputs.) You can make an outputgo high by grounding the appropriateinput pin or connector pin. Use thismethod to check each buffer, andcompare what you see with the sche-matic and layout drawings. If you dis-cover anything unusual, power downand correct the problem. This test isvery important because it locates mostproblems very quickly.

When you're certain everything is inorder, power down and remove theMaster Control Card from the BusCard slot. Then, still with power off,plug the Slave Control Card into thebus (remember to observe proper ori-entation), and test it in the same man-ner as you did for the Master ControlCard. Remember, though, that theSlave Control Card's inputs and out-puts are the opposite of those of theMaster Control Card.

Power down and plug the MasterControl Card back into the Bus Card,and plug the Data Master Card ontothe Master Control Card, leaving thespacers and screws off at this point.Testing both Data Cards is the sameas for the Control Cards.

Check each input using the ground-ed clip lead, and check for outputswitching at the appropriate outputpins. (Make sure you ground only theinput pins, not the outputs. Thoughit's unlikely, shorting the outputs ofthese chips could damage the buffers.)

To test the 74S38 ICs, you mustground pins 9 and 10 of U7 to forcehigh output pin 8 of this chip andenable U4 and US. Then use a 4,700 -ohm series resistor connected to the+ 5 -volt power connector to "probe"the inputs at pins 1, 4, 10 and 13 of U4and US. The appropriate open-collec-

PC-BASEDDEVELOPMENT

TOOLSIf you're interested in microprocessor -related projects,our tools can help. Our PIC microcontroller tools allow

you to learn about and use single -chip computers.And our EPROM emulators are time-savers in

almost any project that uses EPROMs.

MICROCONTROLLER PROGRAMMER

C5x-rur ^ /NM

The PIC 16C5x family of microcontrollers are inexpensive,8 -bit, single -chip computers. They combine a CPU, EPROM,

RAM, and I/O for as little as $3.00 each. Our tools allowyou to program these parts with your own software. A singlePIC can replace many ICs, in addition to adding realintelligence and flexibility to your designs.

Includes assembler, programmer, and cables.PIC is a registered trademark of Microchip Technology, Inc $199

27256 EPROM EMULATOR

Rialltel X BC,12K PI UPI

'.(Asirte-mal

A

ROM EMULATOR

PESE E j

- -- - -

1.tN

If your projects use EPROMs, you can probably use anEPROM emulator. An EPROM emulator plugs in place of anactual EPROM, but instead of programming parts to testyour code, you simply download to theemulator.

Emulates 2764, 27128, and 27256 EPROMs. $199,

PARA11421)<(916) 721-8217 FAX: (916) 726-1905Parallax, Inc. 6200 Desimone Lane, #69A Citrus Heights, CA 95621

Prices subject to change without notice.California residents add appropriate sales tax.

Add $4.00 for UPS ground, $7.00 for 2nd day. $15.00 for next day.

MasterCard


Prairie Digital, Inc.PC DATA ACQUISITIONSYSTEM - $79

INCLUDES SOFTWARE ON 5.25" FLOPPYMODEL 30 -FOR 386'S, XT'S, AT'S, PS2MODEL 25 & 30'S.

FEATURES:* 24 LINES OF PROGRAMMABLE INPUT/OUTPUT* 8 BIT ANALOG TO DIGITAL CONVERTER* 8 CHANNEL ANALOG MULTIPLEXOR* 12 BIT CMOS COUNTER* PC BUS CARD ELIMINATES USING THE SLOW

RS232 PORT* EASY INTERFACE TO ALL POPULAR LANGUAGES* HIGH QUALITY PCB AND COMPONENTS* A/D CHANNELS SELECTED BY SOFTWARE* OPTIONAL 7 CHANNEL 50V DRIVER AVAILABLE

FOR ADDITIONAL $5

APPLICATIONS:* CONTROL RELAYS, LIGHTS & MOTORS* MEASURE TEMPERATURE, PRESSURE, LIGHT

LEVELS, & HUMIDITY* INPUT SWITCH POSITIONS, THERMOSTATS, &

LIQUID LEVELS* GREAT FOR ROBOTICS, SER VO CONTROL LOOPS

MODEL 150 TRUE RMSDMM W/RS232 PORT - $149INCLUDES RS232 PC CABLE ANDSOFTWARE ON 5.25" FLOPPY

Eli rill 41 AC Tir

* LARGE 33/4 DIGIT DISPLAY (3.999 VS. 1.999 FOR3 1/2 DIGIT METERS)

* RS232 SERIAL INTERFACE COMMUNICATES WITHCOMPUTERS AND PRINTERS

* MEASURES AC -DC VOLTAGE AND CURRENT,FREQUENCY, RESISTANCE

* 20 AMP CURRENT RANGE, 30 Hz TO 40 KHzFREQUENCY RANGE

* DIODE TEST AND AUDIBLE CONTINUITY* AUTO -RANGING SELECTION CAN BE DEFEATED

USING RANGE BUTTON* TRUE RMS READING ELIMINATES ERRORS DUE

TO NON -SINUSOIDAL SIGNALS* DATA HOLD, MAX/MIN, AND RELATIVE READING

MODES WITH INDICATORS* ANALOG BAR GRAPH DISPLAY - UPDATES AT 5X

THE RATE OF DIGITAL DISPLAY* OVERALL SIZE 6.4 x 3.1 x 12"* INCLUDES 9V BATTERY AND TEST LEADS

SEND CHECK, MO, VISA, MCINCLUDE $5 FOR SHIPPING & HANDLING

Prairie Digital, Inc.846 Seventeenth Street

Prairie du Sac, Wisconsin 53578U.S.A. Tel/Fax: (608) 643-8599

O tcI,+ V,

0 2O .4

0

0w

8,T,IX

m

tID

Ki

0

>IA

<

m1.,.1.

1.,

IX °:l..l ,..,

0 <. tn... _,

Ncv .4a m,

+

ii0

,O..,

.,,,.

.....

Nce0w L,..> ,(n I,x -1an ,- cr,2.-

inD

,/,

MCVCsl

os.

+ 0a-

,X

<CX

lj L"-12 Ln

Lnco a_- MI --,once --I

..lte <

.-..

\ LaN >1U,

S

,0......

Fig. 9. Wiring details for Master/Slave Data Cards.



0 0o

SdY3 Xflv 0 ,,U <

o3

-L- -, - '

0,.,

ZS

OP,

-(1 i--.C

r2:0:"0

-i11111-

Z3

.,-0+

c': ;7,.n'-'0"-'

,-11_11:7-

.0 (I C)

0

Fj (-.1"' 0..../,.3

,,....,7L.)

-.0' 0+ ,.,

.,,

2 02 ''00+

E,

0 0

Fig. 10. Wiring details for Bus Card.

tor output pin should pull down tonear ground potential as you apply theinput voltage.

Power down and repeat the aboveprocedure with the Slave ControlCard onto which you've plugged theData Slave daughterboard. Checkoutof this pair of cards is almost identicalto that detailed above. Use the appro-priate schematic and layout drawingsas guides as you make your tests.When everything checks out okay,you're ready to proceed to installationof the CYANCE Bus Expander in theCYANCE enclosure.

InstallationWith the CYANCE Bus Card eithermounted in its enclosure or out onyour work surface, plug the controlcable into the Master Control Card.Then plug the data cable into the DataMaster Card and attach it to the Mas-ter Control Card. If you feel confidentthat everything is okay, put the spacersand screws in place.

With no power applied to eitheryour computer or the Bus Expander,plug the Master assembly into slot 8 ofyour computer's motherboard. (Slot8 is the one closest to the processor onmost motherboards.) If necessary,move your video card or any othercard that might be occupying slot 8 toanother slot. Then unplug all otherperipheral cards from your mother-board, making a note of from whichslot you removed each card. The onlyitems you should have plugged into thebus slots of your computer's mother-board should now be a video card andthe Master assembly.

Connect the control cable to theSlave Control Card and the data cableto the Data Slave Card. Now plug theData Slave daughterboard to the SlaveControl Card with spacers and ma-chine hardware. Finally, plug theSlave assembly into the Bus Card.

Turn on CYANCE's power supplyand check for proper operating sup-ply voltages. If everything checks outokay, turn on your video monitor andwait a few seconds for it to warm up.With your scope or DMM probeplaced on the + 5 volt pin of your PC'smotherboard power connector, turnon your computer. If the + 5 voltsupply doesn't appear normal, powerdown and recheck everything.

Once the + 5 -volt bus is operating


properly, leave the power to your PCon and watch for signs of the BIOSbooting on your video monitor. Itshould come up in the usual manner.This is a good sign that your mother-board doesn't mind having the Masterassembly "on -board." You will soonsee a message on -screen that statessomething like, "Can't continuewithout disk!" If your system makesit to this point, simply power downyour computer and switch off theCYANCE Bus Expander.

Next, plug a peripheral card intoany free slot on the CYANCE Bus Ex-pander. (Again, watch for proper or-ientation if the Bus Card isn't installedin the CYANCE enclosure!) I preferto use a modem card or serial card forthis test. Power up the Bus Expanderand then your computer. The lattershould boot as before and give thesame message about needing the disk.If your system does this successfully,it means the CYANCE Bus Expanderisn't interfering with operation ofyour computer's motherboard. Onceagain, power -down both units.

Now plug your floppy -disk (orcombined floppy/hard-disk) control-ler into the bus on your PC's mother-board. Connect the power and datacables to your floppy disk but not toyour hard disk. Place a bootable disk-ette in floppy drive A and close thedoor on the drive. Power up first theCYANCE Bus Expander and thenyour computer. The system shouldboot and load the operating systemfrom the diskette.

With DOS loaded, try a directory(DI R) command. If you see a directorylisted on the screen of your video mon-itor, try loading BASICA or someother program and make sure that itperforms properly. Exit whatever pro-gram you just loaded and checked outand then load a terminal program thatcan access your remote modem orserial card. If the CYANCE Bus Ex-pander is functioning properly, youwill obtain normal operation.

The acid test for the CYANCE BusExpander is to power down complete-ly and move first the disk controller,followed by the video card out ontothe CYANCE Bus Card. On power -up, your system may or may not workwith this hardware configuration. Ifit doesn't, your system may be too fastto allow this type of operation. If thisis the case, you needn't worry because

Making Double -Sided Boards

In professional circles, double -sidedprinted -circuit boards have "plated -through" holes (called "vias") that pro-vide conductive bridges between the con-ductor pattern on one side of the boardand that on the other side. The platingthat "bridges" the two sides of the boardis accomplished using a complex numberof steps, using expensive and specializedequipment not normally available tohobbyists and experimenters.

With plated -through holes, ordinarycomponents and hardware are used toassemble a circuit using ordinary solder-ing techniques. If you fabricate your ownboards, you won't be able to plate -through the required holes. Therefore,you have two alternatives from which tochoose when making your own boards.One is to go single -sided and replace theconductors on the side that has the lessercomplex conductor pattern (usually the"component" side) with wire jumpers.The other is to go double -sided but makeprovisions for soldering access on bothsides of the board through which a com-ponent lead or pin or a wire passes.

The CYANCE Bus Expander de-scribed in the main article was designedso that you can fabricate your own cardsat home, using essentially the same tech-niques you'd employ for two separatesingle -sided cards.

Transfer the four mounting -hole posi-tions at the corners of your boards fromthe artwork to the copper surface of the

blanks with a sharp pin, awl or hobbyknife. Then drill the holes in the markedlocations with a No. 68 bit. This stepallows you to register the artwork on thepc blank while exposing each side.

When you set up for exposing theboards, make sure to keep track of whichside of the artwork is inside and whichis outside. Otherwise, you may end upmaking your boards inside out!

Expose the pc blanks and then developand etch them as you would a single -sidedboard. Be careful to avoid scratching theresist on the sides facing away from youas you agitate the boards in the etchant.

When etching is complete, drill all ap-propriate -size holes. The boards for theBus Expander were designed to minimizethe number of connection that must besoldered on the component side. In ad-dition to several IC pins that must besoldered to the pads on both sides of theboard, you must use solid bare hookupwire as "feed-throughs" that take theplace of vias in a number of locations.

This process may be a little more time-consuming than for a single -sided board,but it's worth the effort. Its only majorlimitation, aside from the extra timeneeded to solder connections on the com-ponent side of the board, is that someconnectors must be raised slightly to givesoldering access to the pins between con-nector body and board. This shouldn'tbe a problem if you keep this in mindwhen you position the connectors.

you should really keep your video,disk controller and memory -expan-sion cards as close as possible to theprocessor on your computer's mother-board. Simply locate less -demandingcards in your Bus Expander unit.

In ConclusionBefore signing off, I should mentionthat I've included pads on theCYANCE Bus Card for some small100- to 1,000-pF capacitors to be in-stalled if they're needed to get yoursystem running smoothly. One com-puter with which I tested theCYANCE Bus Expander wouldn'tpermit the disk controller to operateon the CYANCE Bus Card without1,000-pF capacitors installed acrossthe data bus. If you find that your par-ticular systems requires this type ofmodification, install the capacitors onthe CYANCE Bus Card.

Remember that the CYANCE Bus

Expander is basically an experimentalPC bus platform. As such, perhapsyou can improve upon the operationof the basic unit by making changesthat enhance its performance. If so,you might want to share your ideaswith other users on the CYBERNETbulletin board. To access the NET,simply call 501-839-8293 after 6 P.M.CST. The network is available to allComputerCraft readers who are in-terested in exchanging informationand ideas.

Nick Goss


Application By Hardin Brothers

Adding Mouse Support toYour Programs

Making programs respond to mouse commandscan be deceptively simple

When Apple introduced the Mac-intosh computer, many PC

users commented that they'd never becaught with a mouse on their desks.Today, desktop rodents are a familiarpart of most computers, whether theyuse DOS, Microsoft Windows, theMacintosh operating system or some-thing more exotic.

If you're a programmer but havenever written a program that makesuse of a mouse, you may think thatadding mouse control is difficult. Onone level, at least, it's very easy to in-clude mouse support in your programs.The mouse driver, MOUSE.SYS orMOUSE.COM, supplied with everymouse does the work of displaying themouse cursor, moving it around thescreen and interpreting button clicks.

Your software communicates withthe mouse driver with simple interruptcalls. Your software can ask for thestatus of the mouse, its current posi-tion and whether a button click has oc-curred. If the mouse driver senses abutton click, it tells your program thescreen coordinates of the cursor whenyou press the button and which but-ton is pressed. Your software can alsouse the mouse driver to set the text andgraphics mouse cursor, turn on andoff the mouse cursor, position the cur-sor anyplace on -screen and ask themouse driver to perform a number ofother housekeeping tasks.

It's all pretty simple, but deceptivelyso. The only rule you have to followis to turn off the mouse cursor beforeyou update the screen and then turnback on the cursor to avoid having"ghost" mouse cursors showing up all

Menu:Display MenuGet User's ChoiceCall Chosen RoutineGo to Menu:

Fig. 1. A simple menu system.

over the screen. Otherwise, communi-cating with a mouse is simpler thanworking with any other piece of com-puter hardware except, perhaps, thekeyboard.

It doesn't take most programmerslong to realize that learning to commu-nicate with the mouse driver isn'tenough. Unless your program insiststhat input come from the mouse in-stead of the keyboard, you'll want tocreate a modern mouse -and -keyboardinterface. And you'll find that doingso brings you face to face with all sortsof complications. For example, sup-pose your program begins, as manydo, with a full -screen menu. No mat -

Put cursor bar on default itemGet User's Choice:

Wait for a keyIf it is a cursor key

Move the cursor barIf it is a "hot key"

Move cursor bar to keyed itemIf it is an Enter key

Select highlight itemIf no item is selected

Go to Get User's Choice

Fig. 2. Get the User's Choice (key-board only).

ter what programming language youuse, the menu routine will looksomething like that shown in Fig. 1.

In a keyboard -only application, thesecond step, getting the user's choice,may mean that you simply get a key-stroke or input line. Even if you adda moving cursor bar to let the userhighlight each choice and then pressENTER, the code is quite simple, as il-lustrated in Fig. 2.

Now add a mouse. You have severalchoices here. If you wish, you can turnoff the mouse cursor and interpretmouse movements as if they're cursorkeys and the mouse click as if it's theENTER key. Lots of programs do this,and they're almost all unsatisfactory.The problem is that users expect themouse to act differently from the key-board. They expect the mouse cursorto move smoothly over the entirescreen and the cursor bar to movewhen the mouse cursor touches newmenu items.

If you want to please users, the "GetUser's Choice" portion of your menuroutine will suddenly seem pretty com-plicated. It may end up looking some-thing like that shown in Fig. 3.

Notice that all we've done so far isimplement a simple, full -screen menu.Now add a data -entry screen with sev-eral fields. In a keyboard -only pro-gram, it's a simple matter to movethrough the fields one at a time, insist-ing that the user fill in each beforemoving on to the next one. If the pro-gram needs to be "friendly," you'llprobably want to add some way to letthe user move backwards and editsome text again. You may even want


Put cursor bar on default itemIf mouse is installed

Turn on Mouse CursorGet User's Choice:

Poll the KeyboardIf a Key is available then

If it is a cursor keyTurn Off Mouse CursorMove the cursor barTurn On Mouse Cursor

If it is a "hot key"Turn Off Mouse CursorMove cursor bar to keyed

itemTurn On Mouse Cursor

If it is an Enter keySelect highlighted item

If no item is selected and mouseis installed

Poll the MouseIf the Mouse has moved

If the Cursor is on a choiceTurn Off Mouse CursorHighlight Item under

Mouse CursorTurn On Mouse Cursor

Else ignore mousemovement

If Left Mouse Button ClickIf the Cursor is on a choice

Select the itemElse ignore the click

If no item is selectedGo to Get User's Choice

Fig. 3. Steps for Get User Choice(mouse plus keyboard).

to provide context -sensitive help withthe F1 function key.

When you add a mouse, the com-plexity of your code increases. Theuser will probably expect to select editfields with the mouse, move the edit-ing cursor in a field with a mouse andbe able to select a block of text insidea field by dragging the mouse. You'llhave to keep track of which fieldshaven't yet been filled, you'll needmore -complex editing procedures andyou may want to add a clipboard ofsome sort. You'll need to know whereevery edit field is to match the mousecoordinates with screen locations.And you'll probably want to add an"Okay" button to accept the entireform, a "Help" button for context -sensitive help and maybe other but-tons to run the clipboard.

Of course, your program will haveto keep track of all these buttons andedit fields to know how to react toevery mouse click as well as every key-stroke. And every routine that acceptskeystrokes will also have to know howto react to mouse activities. If you thendecide to add a series of pull -downmenus that can be activated with eitherthe mouse or the keyboard, you'llhave a mass of confusing input in-structions and tests.

If you decide to change the arrange-ment of input fields, entries in themenus, locations or sizes of the but-tons or anything else, you'll face anightmare. You'll have to change allinput routines and location teststhroughout the entire program.

A Different LookDon't throw up your hands in frustra-tion and vow to work with keyboard -only programs forever. There's amuch easier way to handle all thiscomplexity. You may eventually findthat it's easier to write a program witha modern user interface than it is towrite an old-fashioned program.

Early computers ran batch -orientedprograms. An operator gave the ma-chine a program to run and a batch ofdata, often on punch cards or tape,and let it grind away until it had a re-sult. The "user," if there was one,simply told the computer operatorwhat program or data set to run andoften had to wait hours or days to ob-tain the results.

Time-sharing terminals and person-al computers ushered in an age of pro-cedure -driven or "modal" programsthat change from one mode to anotheras user and program move from oneprocedure to another. It's up to the ap-plication designer and programmer todecide what capabilities of the pro-gram are available in each possiblemode. For example, many word pro-cessors leave edit mode and its capabil-ities when print mode is selected.

It's very difficult to add a modernuser interface, complete with keyboardand mouse support and pull -downmenus, to a modal program. Users ex-pect to be able to access any modethrough menus, but the underlyingprogram is written to work in onemode at a time.

In the last few years, programmershave been slowly adopting a complete-ly different way of organizing pro-grams. Their goal is to write "mode -less" programs that always have allprogram capabilities available to theuser. While few, if any, major applica-tions are completely modeless, manyprograms approach this ideal. Insteadof being organized by procedures,they're organized around "events."

An event in this sense is anythingthat can create a signal. It may be akeystroke, mouse movement or but-ton click or a character arriving at a se-rial port, for example. It might also begenerated internally by the program.At the heart of a program organizedby events is an Event Manager thatcollects events and places them in aqueue or first-in/first-out (abbreviat-ed FIFO) buffer.

The Event Manager is responsiblefor sending event signals to the partsof the program that need them. Forexample, in the data -entry screen I de-scribed above, assume the user has se-lected a block of text. If he now clicksthe mouse on "Edit" on the menu bar,the Event Manager sends the mouseclick to the menu system.

The menu system could then dropdown the Edit menu. If the user nextclicks on "Cut" to move a block oftext to the clipboard, the menu systemmight recognize this selection as a syn-onym for the Shift -Delete keystroke.Instead of performing the cut itself, itwould send the Shift -Delete event tothe Event Manager, which would han-dle this event just as if it had beentyped instead of selected from a menu.

Now the Event Manager wouldsend Shift -Delete to the input -editingroutine, which would remove the textfrom the edit field and send it to theclipboard. At a later time, the user canpress the appropriate keys (Shift -Ins,perhaps) or select "Paste" from theEdit menu. The input -editing routinecould then request the text from theclipboard.

The advantage of using an EventManager is that user input and inter -procedure signals are handled in a con-sistent and simple manner. The userhas wider access to the program's cap-abilities, and the program is much eas-ier to update and change. It's easy toadd another menu item and a new sig-nal-much easier than it is to add a


new feature to a program that has allits procedures communicating directlywith each other.

There are some complications to theabove, however. One is how to organ-ize the Event Manager. If the EventManager spends all its time polling thekeyboard and mouse, there will be lit-tle processing power left for the pro-gram itself. Therefore, the EventManager often gathers user inputthrough a series of interrupts.

Handling the keyboard through in-terrupts is easy. Each time the userpresses or releases a key, the keyboardhardware creates an INT 09 interrupt.Normally, the BIOS handles this inter-rupt by translating the hardware keynumber into the appropriate ASCIIsignal and placing the key into theBIOS type -ahead buffer. An Event -based program can either monitor ortake over INT 09. If it simply monitorsthe interrupt, it knows when to call theBIOS to collect each keystroke as it ap-pears. If it takes over INT 09, it can in-terpret each keystroke itself.

Mouse events can also be collectedthrough interrupts. One of the mouse -driver services tells the driver that aprogram wants to be interruptedwhenever a mouse event occurs. TheEvent Manager merely has to registerthe appropriate function with theMouse Driver.

The Event Manager will probablywant to be called every time the mousemoves to support dragging itemsaround the screen, but most systemsdon't record every mouse movementas a separate event. If the user movesthe mouse back and forth across thescreen several times, a huge number ofevents are recorded, which can over-flow the event queue. Instead, mousemovements are usually accumulatedinto a single event until the signal issent to a receiving procedure. How-ever, mouse button clicks and releases,along with the mouse position whenthey occur, are usually stored as indi-vidual events.

The Event Manager can also cap-ture and store system timer ticks, char-acters received through a serial portand other hardware events in a similarfashion. In some systems, the EventManager really becomes a generalizedinterrupt handler, taking care of sever-al kinds of hardware events.

Another complication is how the

Event Manager sends event signals tothe correct procedures. Though thereare several possible methods to ac-complish this, the simplest seems to befor the Event Manager to keep a listof procedures that are eligible to re-ceive event signals. It maintains thislist in order of eligibility.

When it's time to send a signal, theEvent Manager sends it to the most -eligible procedure first. It does this bycalling this procedure and sending toit the details of the event as a callingparameter. The procedure checks tosee if the signal is, indeed, meant forit. If so, it does whatever needs to bedone with the signal, responding to theparticular keystroke, mouse click orother signal type as it sees fit. It thenmarks the signal as used and returnsto the Event Manager.

If the procedure can't handle thesignal, it simply returns to the eventmanager, which then calls the nextprocedure on its eligibility list. If theEvent Manager has called all proce-dures on its list and the signal stillhasn't been marked as used, the EventManager normally calls a default pro-cedure that simply discards the signalas meaningless for the system.

The procedure at the top of the eligi-bility list is often said to "have the fo-cus" because it usually takes careof standard keyboard input. Mouseclicks are usually handled by the firstprocedure that owns the part of thescreen in which the click occurred.However, a procedure like an openmenu bar can react to a mouse clickaway from its part of the screen bysimply closing the menu and markingthe signal as used.

Event -Based SystemsEvent -based or event -driven systemsrequire programmers to change theirway of thinking about a program. In-stead of a set of procedures that aretightly interrelated, an event -drivenprogram is more like a loose confeder-ation of independent routines. Inmany ways, such programs are easierto write than are conventional applica-tions because the members of the con-federation can often be written, testedand debugged separately.

The underlying Event Manager iscritical to the success of the entire sys-

tern. Many programmers prefer towork with an existing, proven systeminstead of creating their own. Oneevent -driven system, Microsoft Win-dows, is well known. For program-mers, Windows can be frustrating tolearn because it provides such a largenumber of program services and cansend so many different messages andevent signals to each program's pro-cedures.

Another Event -based system that'sgaining a great deal of popularity isBorland International's Turbo Vi-sion, which is available with the new-est versions of the company's Pascaland C + + compilers. Turbo Visionrequires programmers to understandhow to use the object -oriented fea-tures of C + + or Pascal because it re-lies heavily on classes, inheritance andvirtual functions. If you're familiarwith either C + + or Turbo Pascal,Turbo Vision will help you create verypowerful character -based programswhile it takes care of the user interface.Once you understand how the systemworks, you'll find using it is quite sim-ple. Other event -driven systems arealso available.

If you prefer, you can write yourown event -driven programs fromscratch. Languages that can call func-tions by a pointer, like C, are ideal forthis, because the list of eligible signalreceivers is easy to maintain. Also,such languages usually make theevent -gathering portions of the EventManager easy to write. But there's noinherent reason why you couldn'twrite an event -driven program inQuickBASIC, for example, as long asyou're willing to add a couple of as-sembly -language routines. GW-BASIC, however, is probably out ofthe running because of its severelimitations.

Event -based programming isn't asubstitute for the structured program-ming techniques that most of us havelearned. Instead, it's an extension ofthose techniques that makes modernand complex programs easier to build.For short programs that you'll runonce or twice and then discard, it'sprobably more trouble than it's worth.But for professional -looking pro-grams you can enlarge and improveupon without causing a rat's nest ofconfusion, it's the best technique cur-rently available.


Application By Jan Axelson

Detecting & MeasuringPhysical Parameters

How to Use Sensors to Detect and Measure JustAbout Anything

Who makes sensors to measurecarbon monoxide, ultraviolet

radiation or fluid velocity? Is there asensor that can detect cracks or bumpson a surface? How can a sensor's± 12 -volt output interface to a + 5 -volt microcontroller? Is there a way tointerface an analog voltage to a micro -controller port without using eight ormore data lines?

You can do lots of interesting thingswith sensors if you know where to findwhat you need and how to use the sen-sors once you have them. This articlewill help you in finding and using sen-sors in your microcomputer circuits,including finding the right sensor foryour application, interfacing sensorsto microcontrollers and a microcon-troller and BASIC compiler for data -acquisition (and other) applications.

As usual, my focus will be on de-signs that use microcontrollers andother dedicated single -purpose com-puters, rather than general-purposepersonal computers, although youcertainly can interface sensors to per-sonal computers as well.

Sensor BasicsA sensor is a device that responds toa physical variable, such as tempera-ture, light, chemical composition, mo-tion or electrical properties. Otherterms for sensor include detector andtransducer. Table 1 gives a more ex-tensive list of sensor types, whichclearly shows that you can use sensorsto detect and measure all kinds of var-iables, properties and conditions in theworld around you.

In addition to differences in whatthey respond to, sensors also vary inhow they respond. A weather vane,for example, responds to changes in

wind direction by rotating, while astrip of litmus paper responds to acidi-ty by changing color. We'll concen-trate here on sensors that respond elec-trically, usually with a change in volt-age, current or resistance becausethese qualities are most easily detectedand measured by electronic circuits.

Finding SensorsSome sensors are readily available.These include thermistors, which re-spond to temperature, and photodi-odes and solar cells, which respond tolight. (See "A Sensor Roundup" inthe February 1992 issue of Computer -Craft for more on temperature andlight sensors.)

Surplus catalogs sometimes havegood deals on more -exotic sensors. Arecent catalog from All Electronics in-cluded a dollar -bill sensor, severalsound -activated switches and a passiveinfrared detector equipped with se-lectable lenses.

Sometimes you can make your ownsensors from everyday materials. Theconductive foam commonly used tohold CMOS components can doubleas a simple pressure sensor, since itstop -to -bottom resistance decreases asthe foam is pressed. A popular home-made moisture detector is a printed -circuit board with two interleaved butnot touching copper traces. When theboard is wet, water shorts together theisolated traces and changes the resis-tance between them from near -infiniteto zero ohm.

Some projects call for a specializeddevice that you just won't find in theusual sources. While researching thisarticle, I discovered a complete refer-ence for sensor sources in the SensorsBuyer's Guide, published annually by

Sensors magazine. The Guide listsmore than 1,200 companies involvedwith sensors and indexes them accord-ing to property sensed, technologyused, manufacturer and related prod-ucts and services.

From the list of properties sensed,you can select the category that inter-ests you and consult a list of compa-nies that offer products in that area.For example, under Microwave Radi-ation six companies are listed, whileunder Carbon Monoxide, there are 64companies and under Temperature,hundreds of companies are listed.

You can also locate companies ac-cording to the technologies their prod-ucts use: acoustic, bimetallic, Bour-don tube, and so on through zircon-ium oxide.

For more information about a typeof sensor, you can contact the compa-nies listed under the category in whichit's listed. Complete addresses andphone numbers are included. In addi-tion to basic product information andspecifications, many companies pub-lish applications notes to help you usetheir sensors.

Sensors magazine, subtitled TheJournal of Machine Perception, is an-other useful resource. Each issue hasresearch and development news, ap-plications articles by sensor users,new -product notes and my favorite,"Wish List," which publishes readerrequests for sensors to suit unusual ordifficult tasks.

Sensors is mailed free to qualifiedsubscribers, who receive the buyer'sguide at no charge. The guide is avail-able to non -subscribers for $29.95 plus$2.50 for shipping in the U.S. (see theSources list for where to write or callfor more information).

Many sensor companies specialize


Table 1. Properties of Some Sensors, Transducers and Detectors.

Acceleration inductance Mass radioactivitylinear microwave radiation Moisture x-rayrotational power Motion Smoke

Acoustic emission radio frequency Opacity SolarAltitude resistance Particle SoundChemical/gas resistivity Photoelectric intensity

carbon dioxide voltage analog pressurecarbon monoxide Energy interruptive Speedchlorine BTU/heat reflective Straindissolved oxygen Fire Position compressionhydrocarbons Flame absolute tensionhydrogen Flow incremental Surface condition/defectshydrogen sulfide fluid relative Tactileion selective electrodes gas linear TemperatureNOx mass angular ThicknessORP-REDOX steam Pressure liltoxygen Force absolute TorquepH Hardness barometric Turbiditysulfur dioxide Humidity blood Velocity

Color Ice differential angularConsistency Level fluid fluidDensity fluid gas linearDistance slurry gauge VibrationElectrical solid vacuum Visibility

capacitance Light Proximity Viscositycharge infrared Radiation Vision/imageconductivity ultraviolet alpha Weightcurrent visible beta Windfield strength Magnetic gamma directionfrequency direction neutron speedimpedance field strength proton

(Courtesy of Sensors 1992 Buyer's Guide.)

in one product area. One companythat offers sensors in many areas isOmega Engineering. It carries sensorsfor temperature, pH, conductivity,flow, level, pressure and strain. Ome-ga also publishes a set of handbooksthat are actually catalogs with techni-cal references included.

Choosing SensorsTo select the right sensor for a job, youmust first define what you want thesensor to do. From there, you cansearch for a sensor that meets your re-quirements. Following are some of thequestions you'll want to answer aboutyour desired sensor. The answers inparentheses describe a temperaturesensor needed for a temperature con-troller used in film processing:

What property do I want to mea-sure? (temperature)

What kind of output do I need-an-alog, digital, voltage, current, etc.?(eight -bit digital output would beideal, but analog voltage or currentoutput is okay)

What range of inputs do I need tomeasure? (60 ° to 110 ° F)

What power supplies are availableto power the sensor? ( + 12 volts, + 5volts)

What resolution and accuracy do Ineed? (accurate to within 0.5 ° F)

How fast must it respond to inputchanges? (quick response not criticalfor this application)

Only when you've satisfactorily an-swered such questions, you're pre-pared to make your selection.

Working With Analog SignalsThe outputs of most sensors are ana-log voltages, currents or other quan-tities that vary continuously betweenlimits. An output may range from 0 to1 volt, 0 to 100 milliamperes or withinsome other range, depending on thesensor. This presents a problem formicrocomputer interfacing, sincecomputers are digital devices that ac-knowledge only two voltage levels,high and low. To interface a sensor toa microcomputer, its analog output

must be translated to a digital formthat the computer can understand.

Sometimes this is easily done. Someintegrated sensors contain their ownanalog -to -digital (A/D) converters,saving you the trouble of providingthem. Some microcontrollers alsocontain their own A/D converters.Probably the best known of these isMotorola's 68HC11, which can di-rectly measure voltages at eight 0- to5 -volt analog inputs. Using deviceslike these will simplify your circuitdesigns.

If none of these solutions is feasible,a separate A/D converter can inter-face a sensor's output to a microcom-puter's inputs. All kinds of converterchips are available with varying reso-lution, accuracy, speed, method ofconversion, number of analog inputs,and so on. One example is NationalSemiconductor's ADC0848, which isan easy -to -use, low-cost, general-pur-pose, eight -channel A/D converter.

In many ways, the ADC0848 is sim-ilar to National's long -popular ADC -0809 A/D converter, but with some


19

.45V9

18 14

PI.7 A1528

27 27PI.6 A14

266P15 A13

255PI.4 Alt

4P1.3 Al

24

3 8031P12 MICROCONTROLLER A10

23

2 22-21

PI.0 A8-

15P3.5 AD7

3

3314P3.4 AD6

340P3.3 ONT I) ADS

3512P3.2 (NTO) AD4

36IIP3.1 AD3

37P3.0 AD2

38ADI

39ADO

GNDA ALE PSEN WR RD120131 130 129 16 17

5V

1383 -T0 -8 -LINE

DECODER

7 E000

5V9 C000

10 A000

I 8000 '138 outputs select 24 11

12 6000 RAM. EPROM. anddevices

V+ Vref

13

other4000 CHI

14 2000 ADC0848A/D CONVERTER CH2

15 0000 CH3

CH4analog inputs

connects to any< 6unused output of

'138 decoder CH57

13CH6

DB7CH7

814

DB6 915

CH8DB5

16DB/MA4

17DB/MA3

18DB/MA2

19DB/MAI

0DB/MAO

AGND

Can connect to INTO. INTI.or other spare port pin INTR

RD WR DGND

22 _If

Fig. 1. The ADC0848 analog -to -digital converter measures up to eight analog inputs and is easily interfaced to an 8031 or

other microcontroller. (External memory, address latches and other components not used by the ADC0848 are not shown.)

advantages. The ADC0848 doesn't re-quire an external clock, its controlsignals interface directly to many mi-crocontrollers and it's faster, with atypical conversion time of 30 micro-seconds. The ADC0848 is availablefrom Digi-Key and other sources.

Figure 2 shows a circuit in which anADC0848 interfaced to an 8031 mi-crocontroller. The connections aresimilar to those used for memorychips. The converter's RD and WR in-puts are driven by the matching out-puts on the 8031, cs is driven by an ad-dress decoder's output, and DBO

through DB7 connect to ADO throughAD7 on the 8031.

Up to eight analog inputs can con-nect to pins 2 through 9 on the ADC -0848. The potential at Vref determinesthe converter's full-scale voltage,which is the input that results in anoutput of 11111111, or 255 in decimal.For maximum range, connect Vref to

the + 5 -volt supply or to a more -pre-cise 5 -volt reference like an LM336-5.0reference diode. The analog inputs canthen range from 0 to + 5 volts.

If your sensor's output is much lessthan 5 volts, you can connect Vref to avoltage slightly greater than the max-imum voltage you expect to measure.This will give you more precise read-ings than you would get with a 5 -voltreference.

To illustrate, consider a sensorwhose output ranges from 0 to 0.5volt. The eight -bit digital output of theconverter represents a number from 0to 255. If Vref is 5 volts, each countequals 5/255, or 19.6 mV. A 0.2 -voltanalog input results in a count of 10,while a 0.5 -volt input results in a countof 26. If your input goes no higherthan 0.5 volt, your count will never gohigher than 26, and the measuredvalues will be accurate to within only20 mV, or 1/255 of full-scale.

However, if you adjust Vref downto 0.5 volt, each count now equals0.5/255, or 2 mV. A 0.2 -volt inputgives a count of 102, a 0.5 -volt inputgives a count of 255 and the measuredvalues are accurate to within 2 mV (ig-noring other sources of error for now).

Layout of ground wires or traces isimportant in circuits that mix analogand digital circuits. The rapid switch-ing of digital circuits can cause spikesin the ground lines, and these cancause errors in analog measurements.You can minimize the problem by pro-viding separate ground paths for an-alog and digital signals. The twogrounds should connect at only onepoint, and this as near the power sup-ply as possible.

In Fig. 3, this means that AGND andany ground connections related to theanalog inputs or Vref follow one path,while DGND and other grounds forlogic, computer, or memory chips fol-


CHI SENSOR I

ADC08480 -12

3

SENSOR 2CH3

0-14

CH57

CH68

CH7

CH8

AGND

(A)

ADC0848CH 1

CH2

CH3

CH4

CH5

CH6

CH7

CH8

SENSOR I

4 SENSOR 2

(B)

ADC0848CH I

CH2

CH3

CH4

CH5 -67

CH6

CH7 .8

8

CH8

SENSOR I

4 H SENSOR 2

5

(C)

Fig. 2. Three measurement modes avail-able with the ADC0848 converter: (A)single -ended, (B) differential and (C)pseudo -differential.

low a different path. The two pathsmeet only at the power supply. Noticethat the schematic diagram uses differ-ent ground symbols for the two signalpaths.

Measuring ModesTo allow for different circuit require-ments, the ADC0848 offers a choiceof three software -selectable modes ofoperation: single -ended, differentialand pseudo -differential. Fig. 2 illus-trates this.

In single -ended mode, each analoginput is referenced to AGND. This isthe simplest mode and will work finefor many applications.

The other modes are useful formore -critical measurements, whereyou must reject background noise ofoffset voltages and measure only thesensor's response to a desired proper-ty. In differential mode, each channelis paired with an adjacent one, withthe voltage on one channel referencedto the voltage on the other.

For example, you could connect anoutput from a sensor to Channel 2 anda ground or other reference from thatsensor to Channel 1. With differentialmode selected, Channel 1 will read thedifference between Channel 1's andChannel 2's voltage. This mode can-cels out errors due to noise, such as60 -cycle interference, that's commonto both channels in the pair.

The final mode of operation is pseu-do -differential. In this mode, Chan-nels 1 through 7 are all referenced toChannel 8. This allows you to makeseven differential measurements, allwith the same reference. This mode isuseful if you're measuring multiplechannels in the same location.

To begin a conversion on the ADC -0848, the microcontroller writes to theconverter to indicate the desired chan-nel and mode. Bits 0, 1 and 2 specifythe channel (000 = 1, 001 = 2, 010 =3, etc.), and bits 3 and 4 specify modeof operation (00 = differential, 01 =single -ended, 11 = pseudo differen-tial). For example, in the Fig. I circuit,to begin a single -ended conversion atChannel 5, you'd write 0000 1101(0Dh in hex) to the converter's addressin external memory. If pin 23 of theconverter connects to pin 7 of the '138decoder, the converter's address isE000h.

After writing to the converter', theconversion is triggered automatically.When conversion is complete, a readoperation to the converter's addresscauses the the converted value to ap-pear at DBO through DB7, where themicrocontroller reads it.

The INTR pin indicates when a con-version is complete and can be used totrigger a read. INTR is low when a Con-version has occurred that hasn't yetbeen read. It goes high after a read andremains high until the next conversionis completed.

You can connect INTR to an inter-

rupt pin on the microcontroller andwrite a routine to cause the microcon-troller to read the converter when aninterrupt occurs. Or you can connectINTR to a port pin that you read to en-sure that it's low before reading avalue, or you can ignore INTR and justbe sure to wait the maximum conver-sion time of 60 microseconds beforereading a value.

National's Linear Data AcquisitionDatabook (also available from Digi-Key) has complete specifications, ap-plications information, and examplecircuits for the ADC0848. You'll wantthis or a copy of the IC's data sheet ifyou plan to use the chip. Another goodinformation source is National's Lin-ear Applications Databook.

Choosing a ConverterIn addition to the ADC0848, there arehundreds of A/D chips offered bydozens of manufacturers; so youshould be able to find precisely whatyou need. Following are some of thequestions to ask when choosing anA/D converter. Example answers inparentheses describe the ADC0848,using information from its data sheet.

What's the analog input range? (0to V + )

How many channels are there?(eight)

What's the converter's resolution?(eight bits)

How fast is the conversion? (30 mi-croseconds typical)

How accurate is the conversion?( ± 1 LSB, 1/2 -LSB version available,where LSB is least -significant bit)

What are the power -supply require-ments and power consumption?( + 4.5 to +6 volts at 15 mW)

What input modes are available?(single -ended, differential, pseudo -differential)

How is the converter controlled andinterfaced? (control signals are RD,WRand cs)

Are there any special features on -chip, such as sample -and -hold, volt-age reference, etc.? (an internal clocktimes the conversions)

What package types are available?(24 -pin skinny DIP and 28 -pin chipcarrier)

An additional component you mayneed for rapidly changing analog in-puts is a sample -and -hold circuit. Toensure correct conversions, the analog


Vin

0-10V

100K

100K0.1uF T I%

mylar I

47

+I5V

0 6.8K

8 I%

R/C

LM331VOLTAGE -TO -FREQUENCY

CONVERTER

COMP IN

lout

THRESH

GND Iref

Fout

412K

I%

5K:

2

O.OIuFpolypropyleneor otherstable type

5V

10K

3> Fout

h, Ad just For Fout - I kHz/volt

Fig. 3. The LM331 takes a different approach to A/D conversion by converting ananalog voltage into a frequency that a microcontroller can measure at a singleinput pin.

input mustn't change in value whileconversion is taking place.

A sample -and -hold circuit ensuresthat the analog signal is stable by sam-pling the signal at the desired measure-ment time and storing it, usually as acharge on a capacitor. This storedsignal is used as the input to the A/Dconverter.

When do you need sample -and -hold? The ADC0848 requires 60µs orless to convert; so you should have noproblem with inputs that don't vary inthis amount of time. When a rapidly -changing input does require one, sam-ple -and -hold ICs like the LF398 areavailable, or you can use a converterlike the ADC0820, which has an on -chip sample -and -hold.

A Different ApproachNot all microcontroller circuits haveexternal memory space available foruse by an A/D converter. In some de-signs, the microcontroller stores itsprogram on -chip, with only a limitedseries of port pins for access to othercomponents. In this situation, you

could connect an A/D converter'sdata and control lines to port pins onthe microcontroller if enough areavailable. Using an A/D converterthat outputs binary numbers in serialformat is another option.

Another method takes a differentapproach and requires only one portpin per channel. Instead of convertingthe analog voltage into a binary num-ber, you convert the voltage into asquare (or rectangular) wave whosefrequency varies with the voltage. Fig-ure 3 shows such a circuit, using Na-tional Semiconductor's LM331 preci-sion voltage -to -frequency converter.

You can connect the output of theLM331 (Font) to a microcontrollerport pin and program the microcon-troller to measure the period or fre-quency of the signal using on -chiptimer/counters. An added advantageof this method is that the frequencyoutput can be transmitted over dis-tance with greater noise immunitythan an analog voltage.

To measure frequency, one of themicrocontroller's timers is pro-grammed to run for a specific period,

such as 1 second. During this period,the microcontroller counts pulses atFont. After 1 second, the count equalsthe signal's frequency. Since the fre-quency is proportional to yin, youhave, in effect, measured the voltage.

An alternative is to measure Font'speriod. With this method, a counteris triggered on and then off when pre-defined signals (such as a falling edge)occur at Font. The resulting count isproportional to Font's period, or 1/frequency. If a 1 -MHz counter isturned on for one cycle of Font, itscount will equal Font's period in mi-croseconds.

If you plan to use this type of con-verter, make sure your microcontrol-ler and control program are fastenough to measure the converter'soutput frequency without missing anycounts. The lower the output frequen-cy, the easier it will be to count. Someversions of Intel's Embedded Applica-tions Handbook (1989, 1990) containarticle reprint No. AR -517, "Usingthe 8051 Microcontroller with Reso-nant Transducers," that describes indetail how to measure period and fre-quency with the 8051 (and other mi-crocontrollers) and what kinds ofthings to watch out for. (See Intel'snew free Handbook Directory for alist of applications notes contained incurrent handbooks.)

National's Linear Data AcquisitionDatabook has more on the LM331, in-cluding example light -to -frequencyand temperature -to -frequency con-verter circuits.

Level TranslatingNot every sensor has an output that'susable as -is. If a sensor's outputranges from + 12 volts to - 12 voltsand your A/D converter operates at+ 5 volts, you must shrink the signal'srange and shift its level to be compati-ble with the converter.

Figure 4 shows a circuit that can am-plify or reduce an input and can alsoraise or lower signal levels by addingor subtracting a voltage. Separate, in-dependent adjustments control gainand offset. The circuit is a series ofthree op amps: buffer, level shifterand amplifier. The example circuit isdesigned with three of the devices inan LF347 quad JFET-input op amp,selected for its high input impedanceand high speed.


The first op amp is a noninvertingamplifier with V1 equal to Vin. Theop amp presents a high -impedance in-put to Vin, to minimize loading.

The second op amp is an invertingsumming amplifier that shifts V2'svoltage up or down as R.5 is adjusted.Adjusting R5 raises and lowers V2,but V2's shape and peak -to -peak am-plitude remain constant.

The third op amp is an inverting am-plifier whose gain is adjusted by R4.This amplifier increases or decreasesthe peak -to -peak amplitude of its in-put. If Yin varies from + 12 to -12volts, you can adjust R4 for a ± 2.5 -volt swing at Vont and then adjust R5to raise Vont to achieve the desired0 -to -5 -volt swing.

Resistor R4 can increase gain as wellas decrease it. To shift a signal downinstead of up, connect R5 to V + in-stead of V - . If no level shifting is re-quired, remove R5 and connect pin 6only to RI.

Data -AcquisitionChip and SoftwareIn preparing this article, I wrote sam-ple programs using Systronix's BCI51

BASIC compiler ($299) for the 8051family. In many ways, BCI51 is simi-lar to, and compatible with, the BA-SIC -52 interpreter contained in the8052AH-BASIC chip. But becauseBCI51 is a compiler, it creates pro-grams that can run on their own, with-out requiring BASIC -52 in memory.

Because the syntax of the two BA-SICs is similar, you can test your codewith BASIC -52's interactive inter-preter, then compile it into executableform. You can also use BASIC -52 asa monitor program for loading anddebugging your compiled programs.

According to Systronix, BCI51 in-structions typically execute 20% to50% faster than their equivalents inBASIC -52. Along with the compiler,you get a stand-alone 8051 assemblerand utility and sample programs.

Because BCI51 doesn't limit you tothe 8052AH-BASIC chip, you can de-velop programs for other members ofthe 8051 family. In fact, Systronix of-fers an optional set of BCI51 languageextensions ($149) for Dallas Semicon-ductor's DS5000 8051 -compatible mi-crocontroller.

Since Dallas Semiconductor spe-cializes in nonvolatile, battery -backed

RI

VI 10K

Vin

R210K

1/4 LF347 1/4 LF347

RS100K

OFFSETADJUST

-15V

Example application:

Vin

+12V

-12V

V2

R310K

10

GAINADJUST

1/4 LF347

Vout

+5VVout 1-""OV

Fig. 4. This circuit adjusts the gain and offset of an analog signal to make it com-patible with an A/D converter's input.


BIG PR 1 FITS INVIDEO EPAIR!

WORK FROM HOME: EARN $85 HR!-NO EXPERIENCE NECESSARY -

Only requirement That you possess averagemechanical ability and a desire to learn

With the tens of millions of VCR.: andCamcorders in use, there currently is a seriousshortage of trained techs to perfirm cleaningand repair jobs on these populardevices... Learn how you can staryour own highly profitable,Nome -Rased video servicingbusiness...And since up to 95%of all VCR andCamcordermalfunctions aredue to a simplemechanical orelectro-mechanicalfailure, you need not spendmonths or even years ofcomplicated study beforestarting paid, professionalservice work!Let Viejo's Training Program show you how!

CALl. 1-800-537-058924 HIRS-7days a weekor mail coupon today!

VIEJO PUBLICATIONS, INC.4470-107 Sunset Blvd., Suite 600

Los Angeles, CA 90027Yes! Rush me your FREE OPPORTUNITY KIT today!

(Check appropriate box)0 VCR Repair0 Camcorder Repair0 Advanced VCR Repair0 Fax Machine Repairla Complete Training in ElectronicsName

Address

City/State

LZip

Dept. UCCi

Say You Saw It In ComputerCraftCIRCLE NO. 97 ON FREE INFORMATION CARD

May 1992 / COMPUTERCRAFT / 51

ADS -2AUTOMOTIVE

DIAGNOSTIC CODEANALYZER

Three easy steps tocommunication with your

Ford: Plug the ADS -2 into your PC's XT slot. Connect the leads to your Ford. The ADS -2 software will display the

EEC -IV codes being received andtranslate them into english.

Your ADS -2 comes with the ADS -2 PCboard, connectors, easy to use softwareand a detailed users guide.Cost is $98.(GM, Chrysler upgrades available soon.)

OfWon (409) 776-6370Check Money order C.O.D.

131 Ridgeway Colege Station TX 77845


Your name hereYour address

Over_LAZCUSTOM LETTERHEADS

FOR WORDPERFECT 5.0/5.1

Print your own letterhead from WP 5.0/5.1 automatically on your HP LaserJetII or compatible printer. Choose froma wide variety of fonts and styles. Wecan also add your corporate logo atno extra charge. Includes over 75Over LAZ office forms, rubber stampsand page borders. Call, write or FAXfor samples and details.

Only $25 (US), S29 (CDN), + $2 p&h.Check, money order or VISA.

Herne Data Systems Ltd., Box 250Tiverton, ON, CANADA, NOG 2T0

Voice or FAX (519) 366-2732


DOS IN ROM!Tired of waiting for thePrompt? Speed up with anMVS ROM Drive. BootInstantly! Also used forDiskiess Workstations andEmbedded control. Easyto Install half-size card.846 $953606 $2001.44m $303PROM Programmer $95

$95

MerrimackValleySystemsBox 850 Merrirhatk,NH

Phone: (508) 792 9507 M V S

WORLDS SMALLEST PC Irobots-alarms-datalog

3 Easy Steps:1. Develop, debug on PC2. Download, test In SBC3. Bum PROM, stand alone-LCD port -3 ser 2 par-Keyboard In -PC bus-Battery or 5v -BIOS option-Real Tm Cik -LED displayUse Turbo C, BASIC, MASM

8088 SBC$95

Sources

All Electronics Corp.P.O. Box 567Van Nuys, CA 91408-0567Tel.: 1-800-826-5432, fax: 818-781-2653

Binary TechnologyMain St.P.O. Box 67Meriden, NH 03770603-469-3232Fax: 603-469-3530

Dallas Semiconductor4350 South Beltwood Pkwy.Dallas, TX 75244-3292Tel.: 214-450-0400, Orders: 1-800-336-6933

Digi-Key Corp.701 Brooks Ave. S.P.O. Box 677Thief River Falls, MN 56701-0677Tel.: 1-800-344-4539

Intel Corp.3065 Bowers Ave.Santa Clara, CA 95051408-765-8080Tel.: 1-800-548-4725 for literature

Omega EngineeringOne Omega Dr.Box 4047Stamford, CT 06907Tel.: 1-800-826-6342, fax: 203-359-7700

Sensors MagazineHelmers Publishing, Inc.174 Concord St.P.O. Box 874Peterborough, NH 03458-0874Tel.: 603-924-9631

Systronix, Inc.754 E. Roosevelt Ave.P.O. Box 526398Salt Lake City, UT 84152-6398Tel.: 801-487-7412, fax: 801-487-3130

RAM, it's not surprising that theirDS5000 contains 8K or 32K of nonvol-atile RAM that can be used for pro-gram or data storage. Other chip fea-tures include a power -fail warning andautomatic power -down, encryptionlogic to protect unauthorized readingof RAM and an optional real-timeclock/calendar. Dallas' DS5000 SoftMicrocontroller Users Guide has moredetails about the chip.

The BCI51 extensions allow easy ac-cess to the added features, includingvariables for the clock/calendar andcommands for custom power -up andreset options.

A development kit from Dallas (No.DS5000TK , $160) includes a DS5000Twith 32K of RAM, hardware fordownloading software from a serialport to the DS5000, IBM -software forIBM compatibles, documentation anda users guide.

The DS5000, along with the BCI51compiler, is especially suited for por-table data -acquisition systems, wheresensor readings are taken periodical-ly and stored in memory, perhapsalong with the time and date. Manyother uses are also possible, of course.Contact Systronix and Dallas Semi-conductor for more on these products.Binary Technology is another sourcefor 8051 BASIC compilers.

And a final note for anyone who is

interested in digital signal processing:Motorola has a new 68HC16 Tool Kitthat includes an evaluation board,software, guide to digital signal pro-cessing and a kit for building a fre-quency analyzer. Price is $168.16.Contact your Motorola distributor orcall 1-800-521-6274 to locate a distri-butor in your area.

Next time, we'll discuss how timingdiagrams can help you design micro-computer circuits that work and fixones that don't.

Send your comments, suggestions andquestions on topics relating to design-ing, building and programming mi-crocontrollers and other small dedi-cated computers to Jan Axelson,ComputerCraft, 76 N. Broadway,Hicksville, NY 11801. For a personalreply, please include a self-addressed,stamped envelope.

Jan Axelson



Applications By Tom Carlton

Windows & OS/2 ConferenceA glimpse at what's churning for the corporate world

This third anual winter session metfor three days in San Jose, Cali-

fornia, on January 28, 29 and 30.Showing an increased acceptance byFortune -1,000 companies, the themewas "Map Your Corporate MigrationPath Into The 1990s." Several thou-sand people attended, getting thelatest in corporate strategies presentedby industry leaders from IBM, Micro-soft, Borland and others.

The main conference targeted thecorporate environment and was divid-ed into three sections: Conferences,Fast Tracks and Exhibits. All three of-fered something for everyone andmuch more information-and tech-nobabble-than anyone could possi-bly absorb.

Topics ranged from Windows andOS/2 training issues to pen -based sys-tems, font technologies (includingWindows 3.1 on -the -fly font scalingTrueType technology) to groupware,LAN/WAN strategies to mission -crit-ical database front ends, principles ofsoftware design, including OOP (Ob-ject Oriented Programming), to mul-timedia desktop video and in-housedevelopment of CD-ROMs. With thebig guns adding Windows and OS/2to their arsenals, the desktop will sure-ly become a much richer graphical en-vironment over the next few years.

Until this happens, however, thatol' DOS prompt will keep peekingthrough. This could be seen time andagain when industry experts scram-bled to boot a copy of XTree or theirfavorite DOS file manager or reboot-ed Windows after a fearful UAE.Even Philippe Kahn, President/CEOof Borland, prophylactically rebootedWindows while giving sneak previewsof Quattro Pro and Paradox forWindows.

The corporate mobs heard aboutBLOBs. Mr. Kahn introduced BLOBs,which are binary large objects such asimages, video, graphics, audio infor-mation (voice), satellite signals,

Hercules SUPERSTATION 3D offers optional 64 -bit RISC

CAD/CAM objects and intelligentdocuments. Sounds like multimedia tome. Managing these BLOBs requiresnew database management tools andincreased capabilities of client/servertechnologies to acquire, compress,store and transfer these huge chunksof data. These new tools will be fun-damental to this evolving integrationof telephone, television, video and im-aged documents.

To this end, Borland's CEO pre-sented a beta version of Paradox forWindows, with a new level of objectmanagement. Incorporating BLOBsdirectly into a table in Paradox was areal crowd-pleaser. Then playing backfull -motion video BLOBs in a windowbrought another round of applause.You could see Borland's modular-"Lego-like"-developer's tools likeObject Vision and Turbo C+ + blend-ing right into the functionality of theirapplication products.

Windows developers are playingcatch-up to products like Blyth Soft-ware's Omnis 7 that works with Ap-ple's QuickTime multimedia operat-ing -system extensions, allowing usersto add "movie" files to databases.

QuickTime provides a standard meth-od for compressing/decompressing,cutting, copying, pasting and display-ing multimedia data. Microsoft's newMultimedia PC (MPC) extensions at-tempt to address those capabilities andwill probably evolve to be compatiblewith QuickTime.

Still lacking are the ability to effec-tively move behemoth mounds of mul-timedia data in Windows and industrystandards for data compression/de-compression methods for the PC.Microsoft's forthcoming enhance-ments to its MPC extensions will sup-port digital video to compete more ef-fectively with Apple's QuickTime forthe Macintosh. Microsoft says that itsAudio Video Interleaved (AVI) soft-ware will provide an interim solutionuntil Moving Pictures Experts Group(MPEG) compression, which allowsfor full -motion video, is available.

Faced with these new demands formanaging multimedia data, users haveyet to decide what operating systemwill meet the fundamental require-ments of this integrated data environ-ment in a complex corporate world.Their options were being displayed


like salvos on the battlefields of theconference rooms and on the exhibi-tion floor.

NT or OS/2?To address these evolving needs,Microsoft and IBM duked it out onthe exhibition floor for the bestoperating system. Microsoft present-ed a beta Win 3.1 and alpha NT, whileIBM showed OS/21.31 and a beta ver-sion of OS/2 2.0.

Microsoft's emphasis on NT (NewTechnology), combined with interimsolutions using Win 3.1, attempted toout -flank IBM's efforts to convinceusers that OS/2 2.0 is the future for32 -bit computing in the corporate en-vironment. While dozens of IBM em-ployees wore blue and white buttonsreading "I Want OS/2," an appre-hension by others suggested it shouldread "Oh Yes/Too." Still others won-dered if NT would really be MT.

Giving credence to NT, industry ex-perts, like Technology InvestmentStrategy Corp. (TISC), project thatOS/2 2.0 will be dominated in themarket by Windows NTbecause OS/2won't be able to compete against Win-dows' huge installed base, not becauseNT will be a better operating system.Consequently, the battle is on for tech-nohegemony.

IBM says OS/2 is better because itruns multiple DOS sessions and Win-dows applications better than Win-dows, as well as OS/2 applications.Microsoft says, "So what, with the ex-ception of running OS/2 applications,Win 3.1 does the same." And on theexhibition floor, "so what" prevailed.Vendors demonstrated hundreds ofWindows applications/developmenttools, compared to a few dozen OS/2products, most of which were avail-able for Windows. If this is any indica-tion, finding a compelling reason toswitch to OS/2 2.0 may be a difficulttask for many people.

Networking is the other importantfactor determining the ultimate win-ner in the corporate setting. SinceOS/2 is commonly used for network-ing (even Microsoft's LAN Managerruns under OS/2), /Vi'must tackle thistask. So in addition to being fully port-able, Microsoft says NT will have pre-emptive thread -based multitaskingand will include many basic network-

ing functions, such as messaging, di-rectory services, database access, sym-metric multi -processing, fault toler-ance and network security. Since Win-dows is popular as a front-end in cli-ent/server systems, and would be ableto run on servers, this will ease devel-opment efforts, further adding mus-cle to Microsoft's installed -basestrangle -hold.

NT appears on a steady develop-ment path. Early reports indicate thatdevelopers are having a smooth tran-sition with efforts to port existingWindows applications to NT.

One way or the other, a 32 -bit op-erating system is just around the cor-ner. Not only does 32 -bit code runfaster than 16 -bit code, but it alsoallows direct access to larger amountsof memory. And the neotenic trans-formation of intelligence-replacingDOS's brain -dead limitation of 64Ksegments with gargantuan segments aslarge as 4 gigabytes-lays the founda-tion for memory management thatbrings us a much more mature and so-phisticated desktop computingenvironment.

To take full advantage of this, mostof us will need new EISA/MCA busesand I/O cards, as well as a minimumof 8M of RAM. And if history is ourguide, minimums are stifling. We'llprobably need 32M of RAM for effi-cient computing. By all appearances,the 286 is heading south. If NT is inyour future, then the 286 isn't. In fact,already, the new Windows Multime-dia PC (MPC) standard was revised,requiring as minimum a 386/SX. Soyour games and entertainment now re-quire a 32 -bit processor.

On the SidelinesFor those keenly interested in makinghistory today, pre -conference tutori-als offered all -day sessions on optimiz-ing Windows, networking, OLE andDDE, and VisualBasic. While the FastTracks program provided three daysof tips and tricks for installing andconfiguring Windows, programmingin WordBA SIC, programming fornon -programmers and developing tra-ditional business and multimedia pre-sentations.

Sampling as many sessions as possi-ble, I stayed for the full course ofWordBA SIC, a macro language in

Word for Windows. I'm impressed.Similar to VisualBasic, users of Word -BASIC can write programs without acompiler. All Win Word's pull -downmenu commands are available forwriting a script. You take control ofWin Word at the system, global andtemplate levels. Creating interactiveword-processing documents expandsWin Word to a developer's tool. Infact, Microsoft WordBASIC develop-ment team (800-227-4679) will assistyou with a Developer's Resource Kit,lots of information about resourcesand put you in contact with severalleading developers. Check out theMSAPP forum on CompuServe,where Library 12 (Lib12) offers Key-WordHacker.

Oh Yes, TooMore than a hundred technoevange-lists (vendors) hawked their wares tothe thousands of attendees. Therewere no big surprises, but many inter-esting products were well -received. I'llmention a few new or interesting prod-ucts that caught my eye.

Unless you like watching paint dry,Windows users need industrial -strength processing power to obtainsatisfactory video performance,which means raw CPU power orgraphics accelerator boards.

Accelerator boards abound, mostusing either Sierra Semiconductor's S3chip or Texas Instruments' TMS340X0chips. Hercules, rising from the asheslike a Phoenix, offers a new line of im-pressive boards. Its high -end 1,280 x1,024 SUPERSTATION 3D board,using a fully programmable 32 -bitTMS34020 chip equipped with 15 dis-play formats and 16 -million colors,offers blazing colors and an optional64 -bit i860 RISC processor.

Effectively exploiting these newgraphical technologies means corpor-ate and government users need theability to edit documents in electronicform and to develop interactive appli-cations for the service and educationindustries.

Radius Inc. offers one solution fordocument management with its FullPage Pivot color monitor, which dis-plays a full 8 %" x 11 " document. Thepivot feature results from a specialgraphics card that permits 90 ° rota-tion for landscape mode. Therefore,


DC/CADintroducing ... I

THE TERMINATORSuper High Density Router(Complete with Schematic & PCB Editor)

Features the following powerfulalgorithm & capability: Rip -up and Retry cal/ Pre -routing of SMT 04;.! r

components Pric User defined strategies $29te$Pange:

Real -Time clean up passes /49s Real -Time via minimization Window 3.0 capability as DOS Task 1 -mil Autoplacer and Autopanning Two-way Gerber and DXF Automatic Ground Plane vv/ Cross -

Hatching Complete w/ Schematic & Dolly

Libraries Optional simulation capability &

enhanced mode for 386 users

*PCB LAYOUT SERVICE ATLOW COST*

LEASE PROGRAM 8. SITE LICENSE AVAILABLE

a-C1 Lr.71rvxDfip

W1DESIGN[COMPUTATION

1771 State Highway 34, Farmingdale, NJ 07727(908) 681-7700 (908) 681.8733 (FAX)

"DC/CAD ... The focal point of future CAD market"


OPTIMM C U

BEVEL

ZE YOURROSH RPMEOT !

IRTEGRATE THE POWER OF Editors Cross assemblers

Disassemblers Cross Compilers Data Conversion Utilities

Simulators Communications

RRHILIBILLO +TMA MOUE, UOIVERSHL

DEVELOPMEHT / communicaTionsEHVIHOHMEOT SUPPOHTMG:

fill families of cross -assemblers. fill families of cross -compilers. Communications with target CPU. Easg to use pull -down menus. User definable utilities menu. MS mouse or kegboard control. IBM PC or compatible.Ilow you can EDIT, ASSEMBLE,

UPLOAD, DEBUG, and MORE, allfrom within ORE, FAST, EASY -TO -USE MERU DRIVER ERVIRORMERT.

$99.00 + $2.00 P/HTO ORDER CALL OR WRITE:

LIFE FORCE TECHROLOGY5477 RUTLEDGE RD.

viRGinin BEACH, VA. 23161(001)179-3093

i Special View rage Graphics table Window Help

Chaper 12-'se and Maintenanceof the Espresso Yourself Unit

11. Us. whohs. hnod

hom o

Ps.. roteri...u.,a. Fe was (Mt.

Pot

11 rtho,. po.2 Fa... SoUe ran

rap or Laa we an nw,artrah eta wt.cold awe a.on, Wirtmier aw WI la val.

b;rwii ..air au *I.-A..11,4ra talmato a Pip idm ear*ra Ar re qtr.:"

"NC n rta raw n.nn°mold haWaw ea..°,prow.Vwnarvaitorteo.roawa .01.1 .0h,h,u.,. e tee* nwp cry u. te

td.12. ar aroOde, rt, town,* par to wa 36 Wh.

10% m Z (19 85 *

-1 rI e..:n HOME

!.\!c7F0fEMMIIMIIIMIMMc.grame? doc

It:gra e 3 docicAtrarnerl docIcAFreme.ix.L.

eta.) doc

c karn4 6x

A FrameMaker screen with selected page in main window, available files and sam-ples of pages in secondary windows.

it addresses the need for word process-ing in portrait mode and using spread-sheets in landscape mode.

Touch screens are popping -up in ki-osk applications from airline termi-nals to franchised carpet stores. Witha touch of a finger, Elographics emu-lates a mouse with a complete line oftouch -screen monitors and upgradekits that are compatible with Windowsand OS/2 environments.

The new kid on the desktop publish-ing block is FrameMaker. This top-notch workstation program was port-ed to Windows. Unlike most desktop -publishing and word-processing pro-grams, FrameMaker offers condi-tional text and automatic table genera-tion. Conditional text allows users tocreate several versions of the samedocument with one file, specifyingwhich sections of text and graphicswill change. It also features integratedsupport for Desktop Color Separation(DCS) graphics. If you create large,complex technical documents, espe-cially on a network, you may find anew friend in FrameMaker.

Perhaps the most noticeable groupof exhibitors offered Windows andOS/2 development tools. While with-in this group many OOP tool kits werenotable, procedural languages ap-peared dominant.

More powerful than Borland's Ob-ject Vision, though not designed fornovice users, Expert -Ease SystemsInc's Guild lets you build interactivegraphical interfaces for new and exist-ing C applications. Blue Sky SoftwareCorp.'s WindowsMaker Professionalcan be used as a back -end C code gen-erator and as a graphical front-end forcreating user interfaces. Pilot Execu-tive Software Inc's Lightship allowsusers to build their own data -drivenexecutive information systems (EIS).PowerSoft Corp's PowerBuilder per-mits users to create database front -ends for client/server applications.Offering Structured Query Languageprogramming tools, PowerBuilderlets users create fully event -drivendatabase front -ends that are indepen-dent of the interfaces of the existingdatabase packages with which they areand that run as native Windowsapplications.

With the smoke cleared away, themirrors and hyperbolists back in theclosets, you could clearly see battlelines were drawn while large numbersof people placed their bets and otherscalculated their odds. And one thingis for sure: history is in the making.The graphical user interface (GUI) hasmoved swiftly and forcefully into thePC environment.



Application By Tom Fox

Experimenting WithMotorola's MC68HC11 True

Single -Chip Computer

Part 5Using the BUFFALO Monitor and MAG-11 to producean inexpensive single -chip MC68HC11 system

n previous installments of thisIseries, we've discussed the MC-

68HC11 true single -chip microcom-puter, details for building a basic SBCcomputer and an optional battery -power system with Logic Monitor.Last month, we also briefly exploredhow to use the BUFFALO monitorthat makes possible an almost unlim-ited variety of uses for the MAG-11SBC. This time around, we go intomore detail on using the BUFFALOmonitor.

Getting Better AcquaintedThe ASM (line assembler/disassem-bler) will be the primary commandyou use when working with the BUF-FALO monitor. ASM makes it a snapto try out simple programs and can beused for the most complex programyou can devise. Be aware, though, thata sophisticated cross -assembler cansave you time.

One ASM feature allows you to puta program into internal EEPROM asquickly and cleanly as you can inRAM. Except for the fact that the pro-gram in EEPROM remains long afterpower has been removed, it's virtual-ly impossible for you to detect thatEEPROM and not RAM is beingused. And because internal EEPROMis located from $B600 to $B7FF, youknow when you write to these ad-dresses you're writing to EEPROM.

Keep in mind another feature whenusing BUFFALO with MAG-11.When position 1 of S2 is set to ON,

BUFFALO jumps directly toEEPROM so that the program inEEPROM starts automatically.

The source code for the line assem-bler is extensive. The following startsthe line assembler, disassembles op -code at < addr > and then allows youto enter a line for assembly: ASM< ADDRESS > < CR >

Keep in mind the following rules forassembly:

(1) All arguments are in hexadeci-mal. Do not key in the "$" prefix; it'sincluded here only as a reminder thatarguments are expressed in hexadeci-mal format.

(2) The "#" (pound symbol) prefixindicates immediate addressing.

(3) The "," (comma) indicates in-dexed addressing and requires the nextcharacter to be X or Y.

(4) Separate arguments by one ormore spaces or tabs.

(5) Any input after the requirednumber of arguments is ignored.

(6) Upper- and lower-case are treat-ed identically.

The following commands are avail-able to signify the end of an input line:

< cr > -Finds the next opcode forassembly. If there is no assembly in-put, the next opcode disassembled is


retrieved from the disassembler.< line feed > or < + > -Similar to

ENTER, except if there is no assemblyinput, the < ADDr > is incrementedand the next < addr > is disassem-bled.

< > or < -> -decrements<addr > and the previous address isdisassembled.

</ > or < = > -Disassembles thecurrent address again.

< > (period) or < Ctrl -A > -Exits the assembler/disassembler.

The best way to learn how to dosomething is to do it. However, startsimple. The simple program in Listing1 causes LEDI through LED8 on theSBC to flash on and off. Start at ad-dress $B600 to place the code inEEPROM. The source code is in a for-mat that BUFFALO's line assemblerunderstands. Bold entries are what ap-pears on -screen from the BUFFALOmonitor, all entries that aren't bold arewhat you type on the keyboard.< CR > means carriage return (or en-ter, depending on the keyboard youuse). Although you key in a carriagereturn, it doesn't appear on -screen.

Start BUFFALO's Line Assemblerby typing ASM, followed by a spaceand then starting address in hexadec-imal and concluding with a carriagereturn. If the EEPROM is erased thescreen display should be exactly asshown in Fig. 12.

You'll notice several interesting andpossibly confusing features in the Fig.12 listing. After entering ASM 8600and a return, ASM displays on -screenB600 STX $FFFF. This means ASMlooked for an opcode at address B600;since the EEPROM is erased it finds,FF there. However, FF is the opcodefor Storing Index Register X using ex-tended addressing (mnemonic"STX"). Since the erased EEPROMcontains all ls (Fs in hex), ASM inter-prets this as an instruction to Store In-dex Register at location $FFFF.

The opcode listed below the STXxxxx is the new opcode stored thereafter it's entered in mnemonic formfrom the terminal. The "." at the endof the last line terminates ASM.

As you can see, while it's a BUF-FALO dogma that you shouldn't en-ter the "$" prefix to indicate a hexnumber, ASM displays the dollar signfor extended addresses.

After entering a line of code andpressing the return or ENTER key, if

>ASM B600 <CR>B600 STX $FFFF

4FB601 STX $FFFF

B7 70 00B604 STX $FFFF


B7 70 02B60A STX $FFFF

B7 70 03B6OD STX $FFFF





CE 30 00B61C STX $FFFF

09B61D STX $FFFF

26 FDB61F STX $FFFF

43B620 STX $FFFF

20 DFB622 STX $FFFF

CLRA

STAA

STAA

STAA

STAA

STAA

STAA

STAA

STAA

<CR>

7000

7001

7002

7003

7004

7005

7006

7007

<CR>

<CR>

<CR>

<CR>

<CR>

<CR>

<CR>

<CR>

LDX #3000<CR>

DEX<CR>

BNE B61C<CR>

COMA<CR3>

BRA B601<CR>

Fig. 12. BUFFALO displays this listing after start-up if nothing is programmedinto EEPROM.

you see on the next line "rom -xx"(xxis data at this location), the line assem-bler assumes you're trying to entercode into ROM since the memory lo-cation doesn't retain the data you triedto enter. Most likely, the lineassembler is correct. This message ap-pears if the memory to which you tryentering to is defective RAM orEEPROM. Another simple possibili-ty is that the address at which you triedto write has no memory installed.

To execute the program directlyfrom the BUFFALO screen, use theGO command, followed by the ad-dress (first make sure you exit ASM bytyping a period):

> GO B600 <CR >

If you entered the program correctly,LED1 through LED8 should flash on

and off rapidly. Stop the flashing bypressing the RESET switch onMAG-1 1. Turn off power to the SBCand then set position 1 of S2 to OFF tocause pin 17 of U/ to go high whenpower returns.

Now power up MAG-11. Whathappens and why? You answer thesequestions yourself. Keep in mind thatinternal EEPROM is located at ad-dresses $B600 through $B7FF and thatBUFFALO jumps to address $B600 ifpin 17 of U/ is high.

To get back to the BUFFALOprompt, set position 2 of S2 to ON andthen press the RESET switch. You canexperiment with the blink frequencyby changing the instruction at address$B619. Loading the index register witha larger number decreases the frequen-cy, and vice -versa. You may wish toleave the blinker program in


Plan To Move?Let Us Know.

z

V)

X

a.N

EEPROM while experimenting withMAG-11 with the BUFFALO monitorinstalled on the SBC.

Whenever you want to check opera-tion of MAG-11, set position 1 of S2to OFF so that LED) through LED8flash after pressing the RESET switch.To erase the blinker program fromEEPROM, use the BULK command.(Before erasing the EEPROM, youmay want to try out the TRACEcommand.)

Other CommandsAnother simple but useful commandis MEMORY or MM or even the undoc-umented M. Follow this commandwith the address of interest to see thedata contained at the specified ad-dress. Change this data if you like orpress ENTER.

If you'd like to see a large block ofmemory at one time, use memorydump command MD or DUMP, whichcauses your terminal to display thecontents of memory in blocks of 16.The format is: MD <ADDr1 >< ADDr2 > < CR > , where addrl andaddr2 are the starting and ending ad-dresses. If you list only one address,nine blocks of memory are displayed;if you want only one block, makeaddrl = addr2.

The LOAD T command can be a realtime-saver because it allows you todownload S -records (files in MOT -Sformat) via your terminal.

If you have a problem with yourprogram, you can use the TRACE com-mand. Place after this command thenumber (up to $FF in hex) of instruc-tions you want executed and displayedafter each carriage return. If you don'tenter a number, TRACE executes oneinstruction at a time. TRACE starts atthe address pointed to by the ProgramCounter (P register).

Try out the TRACE command on theblinker program discussed above.Make sure the Program Counter ispointing to $B600 using the register -modify RM command to change pro-gram counter P, if necessary. The T

command is the same as the TRACEcommand, except that it saves havingto type four extra letters.

To use the TRACE and BREAK com-mands with MAG-11, jumper fromXIRQ pin 40 of U/ to PA3 pin 5 of U).The simplest way to accomplish this isto tack -solder a length of Wire Wrap

wire between the pins on the solderside of the board. (The latest revision,MAG-1 lb, from Magicland andMAG-11s on -disk pc artwork featurea jumper block that can be used in-stead of a jumper wire.)

A carriage return, without a previ-ous command on the line, repeats thelast command.

As shown in the printout of theBUFFALO monitor last month, thereare several other commands you mightwant to try, but I recommend you useBULK sparingly and avoid BULKALLuntil you know exactly what you'redoing with the MC68HC11 and itsCONFIG register.

Do -It -Yourself SystemThe design of the HC11 and use of theBUFFALO monitor make it unbeliev-ably simple to achieve an MCU-basedturnkey system in which MAG-11starts running a custom program whenpowered up. In addition, this programcan be quickly changed at any time byconnecting the board to a terminal.

The primary limitation to the aboveis the size of the EEPROM, which is512 bytes in the "A" version of thechip. If the source code is written inassembly language and care is taken toproduce tight code, a rather sophisti-cated program can be squeezed intothose 500 bytes, especially withHC11' s greatly expanded instructionset. If you really need more storagespace, the 68HCI1E2 version provides2K bytes of EEPROM.

So far, to automatically run theblinker program in EEPROM, youmust use the BUFFALO monitor orsimilar software, to "point" to theEEPROM. That is, you must some-how get the program started at address$B600. Anticipating that some usersmight want to jump directly to inter-nal EEPROM after a RESET, ratherthan to the RESET vector located at$FFFE and $FFFF, the designers ofthe HC11 provided for this feature inthe internal bootloader firmware con-tained in every HC11 version A,whether or not it has internal ROM.This avoids complicating the chip withanother special mode.

To implement a jump directly to in-ternal EEPROM, place the chip inSpecial Bootstrap Mode (by jumper-ing pins 2 and 3 of JP1 on MAG-11).Then tie together the RxD and TxD pins


Table 1. SMOD and MDAConditions

ModeDescription

Latched at ResetSMOD MDA

Single ChipExpanded MultiplexedSpecial BootstrapSpecial Test

00

0

0

and jumper to a pull-up resistor(jumper pins 1 and 2 of JP12 onMAG-11).

When MAG-11 is configured asabove, the chip will jump directly to$B600 after a reset is issued. The rea-son for this is that in Bootstrap Modethe Bootloader ROM is enabled,which initializes the sd and Port D.The bootloader looks for the $FFcharacter that determines the baudrate. If it finds a break character in-stead, the bootloader jumps directlyto EEPROM. Tying together TxD andRxD provides this break character.

Power down and remove the BUF-FALO monitor EPROM from MAG-11. Then power up again and reset thesystem. You'll note that nothing hap-

pens. After resetting the system, theLEDs won't blink. Examination ofaddress and data lines with the LogicMonitor (if you incorporated it in yourproject) will reveal that the HC11 ap-pears dead.

At this juncture, you might be won-dering what has happened. If you triedthis without first reading about it, youmight be panicked, fearing the HC11has become silicon junk. Nothing thatdrastic has occurred. Remember thatthe chip is in Special Bootstrap Mode,with its external data and address busdisconnected from the internal work-ings. While the HC11 is most likely ex-ecuting all instructions stored in itsEEPROM perfectly, it's operating in-visibly since LEDI through LED8 re-quire external data and address linesto operate.

If you're wondering what good is aperfectly working MCU if it doesn'tinteract with the outside world, keepin mind that the HC11 is loaded withI/O ports that are still active. To dem-onstrate, try a variation of the TEST -6811 program given in Part 1 of thisseries. Here we'll cause LED10 toblink. It's connected to bit 3 of PortA, just as LED1 was in Part 1.

COMPUTER SHOW& SALE SCHEDULE

WHOLESALE PRICES - OPEN TO THE PUBLIC

SAVE $1.00 OFF ADMISSION WITH THIS AD!

MAY 210-3Sat.

MAY 1610-3Sat.

JUNE 610-3Sat.

JUNE 1310-3Sat.

JUNE 2710-3Sat.

NORTHEAST TRADE CENTERWoburn, MA - North of Boston1-95 Exit 35 - South of 1-93-40o Tables

WM. PATERSON COLLEGE - Rec. cr.Wayne, NJ near 1-80 & Route 46Indoors - 400 Vendor Tables

WILLOW GROVE, PA - Near Phila.PA Tpke Exit # 27 - Geo.Wash. Lodge200 Vendor Tables - On Route 611

EDISON, NJ - Raritan Center ExpoNJ Turnpike Exit #10 then Right1,000 Tables - Our Largest Show!

NEW CARROLLTON, MD - Sheraton1-95 Exit # 20-B on Annapolis RoadNo. of DC & So. of Baltimore -25o Tables

KGP PRODUCTIONS, INC.(800) 631-0062

Compact & Versatile

8051 /8052Microcontroller BoardFor Production Applications

Low power CMOS technology Only i 5- 4 5- with Inounting hole, Support, RS1 i1 or RS485 Batten-bac ked RAM sue ket Watc hdog tinter and power -tail Interrupt

c irc nun Parallel I/O. 41n 8 -bit I/O ports Configurable for all known tote -wide de, lies 4 Jumper -Selectable Memory Maps

603-469-3232 FAX: 603-469-3530Call for detailed brochure and quantity pricing

aBinary Technology, Inc.

PAY TV AND SATELLITE DESCRAMBLING

ALL NEW 1992 EDITION ALL NEW

1992 edition update on cable, wireless and satellite. Turn-ons, circuits, bullets.bags. B -Mac blackciphers. Includes now VC plus flues. Our bes: yet. Only$15.95. Other (all different) edaions: volume one (basics), 1989 edition. 1991edition. $15.95 each. MDS Handbook $9.95. Satellite systems under $600$12 95. Any 3/29.95 or 5/$49.95. Scrambling News Year One (154 pages)$39.95. Video $29.95. Scrambling News Monthly $24 95/yr Sample $3. Newcatalog $1. Special this month onntrothIng listed for 599.95.

Scrambling News. 3552F Hertel AveBuffalo. NY, 14216 Voice/FAX (7161-874-2088

CODSAREWK ADD S6

Theonly8051/52BASICcompilerthat is

100%BASIC 52Compatibleand

has fullfloatingpoint,integer,byte & bitvariables.

Memory mapped variables

In -line assembly languageoption

Compile time switch to select8051/8031 or 8052/8032 CPUs

Compatible with any RAMor ROM memory mapping

Runs up to 50 times faster thanthe MCS BASIC -52 interpreter.

Includes Binary Technology'sSXA51 cross -assembler& hex file manip. util.

Extensive documentation Tutorial included

Runs on IBM-PC/XT orcompatibile

Compatible with all 8051 variants

BXC51 $ 295.

603-469-3232FAX: 603-469-3530

Binary Technology, Inc.Main Street P.O. Box 67 Meriden, NH 03770

=EaCIRCLE NO. 74 ON FREE INFORMATION CARD


To program the EEPROM again,use BUFFALO's ASM. Remember tofirst plug the BUFFALO EPROM in-to MAG-11 and jumper pins 2 and 3of JP12. Also, place the HC11 in Ex-panded Multiplex Mode by removingthe jumper from JPII and jumperingpins 1 and 2 of JPI.

Remember, the starting address is$B600. Enter the following, usingBUFFALO's ASM:

CLRASTAA 1000LDX #13000DEXBNE B607COMABRA 8601

Run this program by removing theBUFFALO EPROM from MAG-11and setting the jumpers for SpecialBootstrap operation. Move the short-ing jumper at JP12 from pins 2 and 3to pins 1 and 2. Now press the RESET

switch on MAG-11 and note if LEDIOblinks on and off. Do not try to runthis program from BUFFALO's GOcommand unless you remove thejumper between pins 5 and 40 of U/.

Notice that the system is extremelysimple. Basically, only Ul, U2, QIand voltage regulator U4 are operat-ing. You can build a complete micro-processor project with only a 68HC11

and a microprocessor supervisory IClike the MAX690 or Motorola's MC -34064. Projects like these can be sim-ple in physical design, sophisticated infunction and, best of all, inexpensiveto build.

Until now, you've been operating inthe Special Bootstrap Mode, whichlimits what you can do. However,even though you must start in SpecialBootstrap Mode to enable the jumpdirectly to EEPROM, you don't haveto stay there. You can use software tojump into Expanded Multiplex Mode.

The procedure for getting back toExpanded Multiplexed Mode isstraightforward. All you do is modifythe HPRIO register at $103C usingsoftware.

Bit $103C RESET7

6

5

43

2

0

SMODMODA

x 0x 1

x 0x 1

Here, x stands for the bits that aren'tof interest right now. Table 1 showsthat the condition of bits SMOD andMDA afterRESET depends on the op-erating mode at RESET. With jumpersset for Special Bootstrap Mode, SMOD

+qv

10K

0.125" heat -shrinkable tubing

Red LED on MAG-11 orMAG-11BAT

Phototransistor

NOTES: =Q1 = OP500SLA or equivalent phototransistor.Q2 = 2N2907 or equivalent PNP transistor.K1 = DIP reed relay (Digi-key CAT. No. 26101 -ND).K2 = 16V ac relay with >90t2 coil resistance.

Color -code wires for easyidentification of collectorand emitter

I o

11 K2

16V ac fromtransformer

Fig. 13. Details for making an optical coupler (A) and the schematic diagram (B)of a simple circuit that allows a red type T-1 LED control a power relay (K2) viathe contacts of a low -power DIP reed relay (K1).

and MDA are 1 and 0, respectively.This is the opposite condition fromExpanded Multiplex Mode. The onerequirement is that MDA can bechanged by software only when SMODis set. Thus, MDAmust be changed be-fore SMOD is cleared.

As you can see, to switch to Ex-panded Multiplexed Mode, you wantSMOD cleared and MDA set. In prac-tice, you first write a 1 to MDA to tem-porarily send the MCU into SpecialTest Mode. The next set of instruc-tions should clear SMOD to cause theHC11 MCU to go into the ExpandedMultiplex Mode.

The following short program makesLED1 through LED4 blink on and offat half the rate of the previous blinkerprogram. To program the EEPROM,configure the jumpers for ExpandedMultiplex Mode and plug the BUF-FALO EPROM into socket U7. Re-member to start the program at ad-dress $B600. With BUFFALO'sASM, type ASM 600 <cr> at the" > " prompt and follow with:

LDAA#75STAA 103CLDAA #35STAA 103CLDS #C0CLRASTAA 7000STAA 7001STAA 7002STAA 7003LDX #6000DEXBNE B61CCOMABRA 8600

The first and second lines set theMDA bit; the third and fourth linesclear the SMOD bit; and the fifth linesets the stack pointer. The fifth lineisn't needed, but it's good practice toinclude it.

To try out the program, powerdown and set the jumpers for SpecialBootstrap Mode. (If you wish, youcan remove the BUFFALO EPROM.)Again jumper pins 1 and 2 of JP12.Power up and press the RESET switch.Now LEDI through LED4 shouldflash on and off at a slower rate thanin the program that flashes all eightLEDs. Do not try to run this programfrom BUFFALO's GO command.

You can experiment with your ownunique program to operate automat -


STOPPING POWER METERS

TOP*: MI=M

CONSUMERTRONICS2011 Crescent Dr., P.O. Drawer 537

Alamogordo, NM 88310Add $4 S/H (USA, Canada). All items in stock. COD (UPS cashonly), VISA, MasterCard OK. NEW CATALOG is $2 withorder, $4 without. In business since 1971. As seen on TV. JohnWilliams - former Senior Engineer (Lockheed), Professor ofComputer Science (NMSU). Sold for educational Purposes only.

All software supports all IBM-PC compatible sys-tems (8086 - 80486).Voice Line and Manual Fax: 8AM-9PM Mon. -Sat. MST. Auto Fax: All other times.

(505) 434-0234Fax: (505) 434-0234 (orders only)

Off -The -Shelf HARDWAREVan Eck System, Voice Disguiser, Shriek Module,Hearing Assistor, 6th. Sense Communicator, TENS,Bumper Beeper, Radar Emitter, Subliminal Mixer, EMCountermeasure, Hieronymus Machine, Neurophone -much morel See our Catalog for details.

HARD DRIVE MANUALCovers all hard drive and controller implementations (emphasis onPCs). How to select, interface, initialize, set up, use. maintain.troubleshoot and repair them. How to protect them from mistakes,sabotage, prying eyes and sticky fingers. How to recover dam-aged and lost files. How to prevent crashes to begin with. In-cludes software reviews. Loaded with information, advice, tips.

29.

DISK SERVICE MANUAL am am, rou es oo repair, a. jus a ign oppy rives wi o

special equipment or software - 3.5'15.25'18. PC/XT/AT/3 86/4 86. Apple. Tandy. Commodore, Kay pro, Epson,Atari, TI, HP, DEC, etc systems. All floppies need regular up-keep. $29.

DISK DRIVE TUTORIALTheory and practical facts on floppy drives, disks, FDCs, format-ting, software protection. Systems described above. Invaluableadvice and tips on how to best select, interface and use drivesand disks. $19.

PRINTER & PLOTTER MANUALTypes, descriptions, specs and 100, interfaces (parallel, serial).Detailed plans for X-switchers, buffers, and serial -to -parallel andparallel -to -serial Interfaces, breakout boxes. Many buy, use,service, ties. $14.

COMPUTER PHREAKINGTROJAN HORSES, VIRUSES, WORMS, etc. and counter-measures. Includes disk with 360K of hacker text files and utili-ties, and legendary F LUS HOT+ protection system (Ed.Choice, PC Magazine). Dozens of computer crime and abusemethods and countermeasures. How systems are penetrated.BBS advice, password defeats, glossary - much more! Manuals+ Disks $39.

BEYOND VAN ECK PHREAKINGEavesdropping on VDT and TV video signals using an ordinary TV!Documented in security industry literature. Range up to 1KM.Plans include both the CONSUMERTRONICS and the originalTOP SECRET VAN ECK designs! $29.

ABSOLUTE COMPUTER SECURITYDozens of simple, versatile, secure computer security methodsand tips. Plus our invulnerable Cipher Program (in .COM andIts .BAS source). Plus $1,000 CIPHER CONTEST ruleswith ciphertext. Manual + Disk $24.

CRYPTANALYSIS TECHNIQUESFive powerful menu -driven crypto programs (In .COM and their.BAS sources) to analyze, decrypt "secure" ciphertexts. Worked -out examples. Recommended in the prestigious COMPUTERS& SECURITY. Manual Disk $29.

SOFTWARE PROTECTION SYSTEMUnique system that highly discourages costly software piracywhile not interfering with legit archival copies. No known way todefeat. No special equipment required. Simple and automatic toinstall on your distributed software. Can be used with any copy -

Disk' $59revention s stem.

THE "GOLDFINGER"Tired of digging up rusty nails and bottle caps? The"Goldfinger": Detects GOLD, SILVER, PLATINUM,ALUMINUM and COPPER - Rejects all FERROMAG-NETICS. Plans. $14.

THE "SILKWOOD"The "Silkwood" detects X- and Gamma Rays, and Alpha andBeta particles. Simple, pocketsize, 9 -volt battery -operated reddetector requires no Geiger -Mueller tubes or high voltages. 95+%linearity between 10 and 1K rads/min. Indicates to less than 0.1reds/min. Check out your job, home, land and possessions. And areal lifesaver for nuclear survival situations. Plans. $1 4.

VOICE MAIL BOX HACKINGHow Voice Mail Box (VMB) systems are t.sed and the specificways they are hacked. Includes ASPEN, MESSAGE CEN-TER, BIX, EZ, SYDNEY, PHONE MAIL, AUDIX, etc. Ab-solute r: uired for all users and so s! $29

CELLULAR PHONE MANUALHow cellular phones are designed, operated and re -programmed.How cellular systems are vulnerable to hack attacks, andcountermeasures. Comprehensive descriptions on modifyingNAMs & ESNs (including specific info. on 30 popular models),scanning, scanner restorations (includes UHF TV method), freq. &channel allocations, roamin,, trackin., ECPA - more! $39.

PHONE COLOR BOXESAs designed by Phone Phreaks! 15 phone color boxes described.Dozens of circuits, simulator programs. Plus call forwarding, con-ferencing, phreak history, 50 useful and legal phone circuit plans -more! $29.

ROBOFONE AUTODIALERPowerful, versatile, menu -driven "Wargames autodialer lets youdial any number (up to 10K) or mix of local and long distance num-bers in any order, over any length of time, whether busy or an-swered (your choice) and log the times, commands and results tomonitor, printer and -or disk. Quick -dial directory of up to 600 num-bers. BUSY rectal options. Direct modem command and control.All Result Codes, including VOICE and RINGING. Optional shell toterminal program upon CONNECT. Exit to menu or DOS (forbatching). Manual + Disk $29.

RADIONICS MANUALExciting electrical, electronic and electromagnetic therapeutic, di-agnostic and preventive devices (mostly experimental). History,descriptions, plans (dozens), availabilities of Radionics De-vices from early to modern. While drugs cost $ Hundreds, etec-tricit costs ennies! $29.

HEAL THYSELFSome electronic and electromagnetic medical devices are now li-censed by the FDA for therapies. Plans for three major devicetypes that YOU can build and use yourself! Save $ Thousands!Plus details on man other devices. $1 9.

EM BRAINBLASTERTutorial and plans for powerful ELECTROMAGNETIC WEAP-ONS and LAB DEVICES. Optimum circuits, freqs., waveforms.duty cycles and intensities. Comprehensive and MIND BOG-GLING! $29.

UNDER ATTACK!' ' (EMI) andELECTRONIC WEAPONS cause inexplicable manifes-tations! These attacks can cause cancer, birth defects, pro-found psychological and neurological disorders, cardiovascularand immune system failures, etc. Destructive to people, pets,livestock, plants, equipment. INCLUDES ACTUAL CASES(which we investigated and documented) OF EM ATTACKSON PEOPLE. Includes how you can verify and pinpoint thesource of EMI and electronic attack, and specific countermea-sures ou can take. $29.

HIGH VOLTAGE DEVICESHV devices plans: Stun Gun, Taser, Prod, Cane, Um-brella, Flasher, Blaster, Zapper, RF/Radar/Audio Jam-mer, Jacob's Ladder, Plasma and Van de Graaff Gene.,Fence Charger, Geiger Counter, Ozone Gen, FishStunner, Plant Stimularor, Kirtien, etc. Shockin I $29.

SECRET & SURVIVAL RADIOOptimum survival and security radio equipment, methods, freq. al-locations and voice/data scrambling/encoding. Includes small re-ceivers/transmitters, telemetry, antenna optimizations, remotemonitoring & control, security, surveillance, and ultrasonic,fiberoptic & infrared commo. 70, circuit plans, tables. $29.

TV DECODERS & CONVERTERSTutorial, plans for several popular TV decoders and convertersPlus satellite TV component selection use t s. 1 4.

VOICE DISGUISERPlans for neat devices to change voice pitches. Effective againstsnoops using voice analysers, for women, chldren and elderly liv-ing along, for anti -intrusion systems, for gags. Voice soundsnatural. $19.

STEALTH TECHNOLOGYPolice radar is fascinating! It also has error rates of 10%-20%!Every known error mode method and matelal used to minimizeradar reflections - tactic & strategy to fight unjust radar tickets(that cost you $ Hundreds In Insurance and risk cancellation) -methods to detect and 'am st. nets - full described! $29.

CREDIT REPORTING ENTITIESGiant commercial and government databases contain millions offinancial, employment, medical, family history, lifestyle, religious,political records instantly accessible to many How to protect yourprivacy and security. Comprehensive. $29.

SECRET & ALTERNATE IDSPrivacy is virtually gone) With the huge databases nowmaintained and controlled by credit bureaus and governments,your privacy, sanity and survival are at great risk - unless you canescape under a secret and alternate ID. Legal methods detailed.Not a rehash of the Paper Trip books. $14.

BY AN ORDER OF THE MAGNITUDEThe most comprehensive survival book ever written!Topics include electronics, compUters, energy, weapons, con-cealment, revenge, alarms, etc to survive today and In the DayAfter. We all face increasingly financially and physically brutaltimes! Field -expedient use of technology in various threat andconflict environments. $49.

As reported on CBS 60 MINUTES': How certain electri-cal loads (simply plugs into an outlet) can slow down- even stop - watthour meters - while using full loads!Loads may be connected to any outlets in system. Also describesmeter creep, overload droop, etc. $19.

THE I.G. MANUALerne magnetic ways app -. to sow own

and stop watthour meters while drawing full loads. $1 9.

KW -HR METERSHow watthour meters work, calibration, error modes (many), ANSIStandards, etc. Demand and Polyphase Meters. Experimen-tal results to slow and sto. meters b others. $19.

LIBERATE GAS & WATERHow gas and water meters can be reversed using commonly avail-able household equipment. $19.

GAS FO' ALL!Every known vulnerability of gas and diesel fuel pumps and dis-pensers - both mechanical and electronic. $19.

VORTEX GENERATORHeat and cool with simple, amazing 3 -port device. Uses no movingparts, electricity, fossil fuel, liquid or freon. Guaranteed scientifi-cally sound! Plans. $14.

BEST -BUYBig -ticket items (ex: vehicles, computers & peripherals, video &photo equipment, home appliances, copiers, etc) come in a dizzy-ing array of makes, models and features. BEST -BUY is a power-ful, easy -to -learn, easy -to -use, menu -driven analysis programthat computes the very best buys for your hard-earned dollars.Save much UV Disk + Write -U $29.

STOCKPROUnique, powerful, shrewd and unconventional common stock in-vestment strategy. Professionally created for NMSU and core ofcostly consulting package. Manual r Disk $29.

AUTOMATIC TELLER MACHINEScrimes. a iuses, vu nerai ll les an. e eats ex-

posed! 100+ methods detailed, Include: Physical, Reg. E, ci-pher, PIN compromise, card counterfeiting, magnetic stripe, falsefront, TEMPEST, tapping, spoofing, inside job, super -cool, vibra-tion, pulser, high voltage, Van Eck - others. Case histories, law,countermeasures, detailed security checklist, labeled internalphotos, figures. ATMs contain u to $250,000 in cash! $350,000ATM crime spree still unsolved! 9

CREDIT CARD SCAMSCardholders, merchants and banks suffer $ Billions in losses an-nually because of credit card fraud. Describes every knownmeans of credit card fraud & scams. Protect yourself! $29.

CONS & SCAMSns an cams leece mericars o : illion per year. he

most comprehensive survival manual on cons and scams of allkinds - from the classic to the hi -tech. Details on hundreds andtheir many variations. Protect yourself I $29.

ULTIMATE SUCCESS MANUALUnderpaid? Harassed? Manipulated? Stuck in a dead-end job? Ex-pect to be laid off, fired or transferred? The ultimate no -holds -barred Machiavellian techniques to find, obtain, optimize and keeptop jobs and benefits. THE RULES OF THE GAME FOR AGAME WITHOUT RULES! From first resume to CEO. $29.

SURVIVAL GUNS & AMMOThe Ultimate Firearms Survival Manual! Describes opti-mum guns & ammo, conversions, silencers, explosive devices,improvised weapons, End Times scenarios, retreats, etc. $19.SILENCE IS GOLDEN: How acoustic silencers are made fromsimple, cheap, commonly -available materials. $9. Both $25.

ROCKET'S RED GLAREHow to design and build solid -propellant amateur and survivalrockets. Emphasis on the formulation, manufacture and installa-tion of propellants, motors, igniters, etc. Includes list of com-monly available materials, and the design of launch pads and testbeds and their electronics. $29.

FIREWORKSDescribes how firecrackers (M -80s, blockbusters, cherry bombs),rockets, volcanos & fountains, sparklers & safety fuses are made& colored. Slm le, Max ensNe & common In redients. $9.

NEW CIRCUIT DESIGN CONCEPTDescribes new circuit design "MAGIC POLYHEDRON" con-cept. Soldering typically reduced to less than 20% of PC and perfboard designs - much less risks of toxic chemicals, burns, badsolders, cooked parts, etc. Compact, efficient, low -noise, reliable.Versatile size, shape, layout. Easy to troubleshoot and changedesign. Cost effective. Easy to integrate with chassis, controls,connectors, displays, power supplies, etc. Assemble circuits justabout anywhere! $19.

TECHNICAL RESEARCH SERVICESUnique 57+K electronic & computer design article database ac-cessed by title & subject: Digital, pP, pC, analog, hybrid, no-mograph, software. Many hacker, inhouse & non -published. Pro-vide us keys, we return list. $25 search fee (1-25 keys; you maycombine unrelated topics). Saves you R&D MI

SPECIAL PROJECTSWe design, build, repair, modify, maintain and -or consult on anydevice, system, process, project (electrical, electronic, comput-erized, mechanical, optical, automotive). Invention prototyping.Confidentiality guaranteed. Describe and Include $25 fee (doesnot obligate you). We then provide you cost & time estimates.


50000

SOOFF

$0100

SO1FF

$1000

0103F

$IM

S1FFF

$2000

Internal RAM`

External RAM provided byoptional U9

Internal register*


Not

$6FFF

$7000

$7FFF

$8000

Used by MAG-1 1 LEDs,switches, etc.

Unprogrammed bytes in U7

$B5FF

$8600

Internal EEPROM

$B7FF

$8800"

$BFFF

$C000

Diagnostic program in U7(see text)


$F7FF

$F800

Diagnostic program in U7

$FFFF -

NOTE:

Internal RAM`


Internal register*


Your program (in U10)goes here



Internal EEPROM

Diagnostic program in U7(see text)

- -


Diagnostic program in U7

*Internal RAM and internal registers can be remapped (see text)

$OFFF

$E000

Internal RAM*


Internal register*

External RAM providedby U10



Internal EEPROM


Buffalo monitor in U7

Fig. 14. Memory map for MAG-11 single -board computer.

ically when the jumpers are set forSpecial Bootstrap Mode. (MAG-11-BAT's Logic Monitor is ideally suitedas an output display for experiments.)For instance, you can connect shortlengths of No. 24 hookup from thePort A outputs of Ul (such as, PA4,

PA5 and/or PA6) to J1 on the LogicMonitor. (As can be seen from MAG-11's connector pinout illustrationshown last month, PA4, PA5 and PA6

are connected to pins 8, 6 and 4,respectively, of J3.)

With a suitable program, you cancontrol the respective Logic MonitorLED. For instance, if you connect PA4

to pin 1 of J1, LED12 on the MAG-1 1BAT board will light if bit 4 of PortA at $1000 is set, and LED20 will lightif this bit is cleared.

You can modify MAG-11BAT so itwill serve as an optically -isolated out-

put board that can control relays. Usea short length of heat -shrinkable tub-ing of suitable diameter to opticallyconnect a phototransistor to one LEDon MAG-11BAT. If necessary, useblack electrical tape to seal out exter-nal light. Connect the phototransistorin a simple circuit that controls a smallDIP relay. A sample circuit is shownin Fig. 13.

While the relay mentioned can con -


Hardware & Software Availability

Parts and software for the MAG-11single -board computer system areavailable from Magicland, 4380 S. Gor-don Ave., Fremont, MI 49412. These in-clude: double -sided MAG-11 pc boardwith plated -through holes and screenedcomponent overlay, Part No. MAG-I 1BD), $25; all ICs, except optional ones,including the MC68HC11A1P and a27C256 EPROM with MAG-11DIAG orBUFFALO firmware (specify choice)and JB31J1 thermistor, 7,320 -ohm 1%resistor and a loaded PC compatibleMAG-11 software disk (specify 5 " or31/2 ") but not including U9 or U10, PartNo. MAG-11CDK, $49.50. Order bareMAG-11 pc board and set of ICs anddisks, and pay just $69.

Available separately are: MC-68HCI1A1P, $25; 27C256 EPROM withMAG-I 1DIAG firmware, Part No.MAG-11DIAG/E-256, or BUFFALOmonitor, Part No. BUFFALO/E-256,$12 each; PC -compatible disk (part No.6811ME-5 for 5y4" or Part No. 6811 -ME -3 for 31/ "), $7.50. All prices are post-paid in the U.S.; add $5 for shipment toCanada, $10 for shipment via air to othercountries. Michigan residents, please add4% for sales tax.

Motorola Freeware BBS-Tel.: 1-512-891-3733, 2400/1200/300 baud, eightdata bits, no parity, one stop bit.

trol up to only 0.5 ampere directly, itcan be used to activate a power relaythat, in turn, can control devices withlarger current drain. It would be sim-pler, and probably more reliable, toconnect an optoisolator directly to theoutput pins of Port A-but it isn't asinformative or as much fun to do itthis way.

Complete Memory MapFigure 14 shows the complete memorymap for MAG-11. This map is impor-tant if you plan to expand MAG-11.Notice that there are a substantialnumber of bytes that aren't pro-grammed in EPROM U7. You caneasily add a complex program to eitherthe diagnostic or BUFFALO -monitorEPROM. The 68HC11A1P permitsconsiderable flexibility in reposition-ing internal RAM and I/O registers,to the beginning of any 4K -byte page.The INIT register, located initially at

$103D, sets the addresses for RAMand the I/O register.

Bit7-RAM36-RAM25-RAM14-RAMO3-REG32-REG21-REG10-REGO

RESET0

0000

00

RAM3 through RAMO specify the up-per hex digit of the RAM address. Asyou can see, after a reset, these bits are0; so RAM is initially positioned from$0000 to $00FF. Similarly, REG3through REGO specify the upper hexdigit of the I/O registers. After a reset,bit 0 is 1 and all other bits are 0; so the

I/O registers are initially positionedfrom $1000 through $103F.

If RAM and registers are inadver-tently mapped to the same space (forexample, if the INIT register is cleared)the registers have priority. With the"A" version HC11, internalEEPROM is fixed between addresses$B600 and $B7FF.

Now that you've built the MAG-11SBC and its companion MAG-11BATadd-on battery board with LogicMonitor and experimented with them,you'll undoubtedly want to begin ex-perimenting on your own. A goodplace to start is with this series of ar-ticles. Follow up with the manuals anddownloaded software from Motoro-la's Freeware BBS to get more in-depth experience using these items.

AC/DC VOLTAGEAC/DC CURRENTDIODE TEST Stock No.LOGIC TEST 990092LED TEST GOOD/BAD5 FREO RANGES5 CAPACITANCE RANGESLOW BATTERY WamlngCONTINUITY TEST/BUZZERTRANSISTOR CHECKER20 MHZ FREO COUNTER VISA

mmo KELVIN ElectronicsMOMOM 10 Hub Drive, Melville, NY 11747

(518) 7S8-1750 1(800) 645-9212FAX (516)756.1763

PRO 400

633 DAY

MONEY BACKGUARANTEE!

,Of0

IMIN TEST EQUIPMENT1

III Power

Generators Frequency Counters

i Pi Supplies Video Head Testers Etc.

Since 1972 CALL OR WRITE FOR OUR FREE CATALOG

BRUNELLE INSTRUMENTS INC.P.O.Box 1223 Newport Vermont 05855

Tel 1-800-567-3506 Fax: 1-819-569-1408

LA1 General -Purpose PC Logic Analyzer - $149.00Designed especially for efficient sophisticated digital analysis of non -microprocessor circuits.

IBM PC/XT/AT/388compatible

3. The first PC LogicAnalyzer designed tobe cost-efficient for low -frequency applications.

*Works with 5 -Volt digitallogic (5V CMOS or TTL).

*8 color -coded datalines & external clockinput.6 range internal clock(1Hz-100KHz) forperiodic sampling.

MOUSEcompatible

48" color -coded ribboncable with spring -loadedmicro clips

"" Uses your PC'smicroprocessor andmemory with an assemblylanguage data acquisitionroutine for maximumspeed on your system.A 12 MHz PC clone easilyhandles over 100,000samples per second.

Add logic analysis to your bench for the price of a DMMideal for the professional as well as students & hobbyists Proven excellent teaching aid

* Integrates with the power & Intelligence of your PC to produce a low-cost yet Impressive test in-strument.

* 'Snapshots" Logic States for observation.Quickly & reliably performs tests that a dual -trace oscilloscope, DMM, and Logic Probe can't (ex-ample: multiplexed digital displays, stepper -motor controllors, . . . etc.).

," Pop -Down Menus. > 8 Channel color -coded logic probe mode.1"' File / Print Utilities. > Free tech support and software upgrades.

Model LA1Byte 1829 1,

(11011C1_1(

1 DO

O 01

02

100I 04-

O 06

O 07-

Photroreca LAI Feb 27,1990Dandy Data Test

111111 1111111111 11111111111111111111111111111111111111111111I

8 16Byte

32Sam pl ed

40B

t ruelaya,v,t.

48 56 64

Full -Featuredsoftware &data displaygraphics (Dis-plays in fullcolor ormonochrome).On-line helpsystem.Takes onlyminutes tomaster theeasy -to -usesoftware.

"" Made In theUSA. 109 Camille Avenue

Amite, Louisiana 70422

Logic AnalyzerComes Completely

Assembled & Testedwith Disk & Manual1 Year Warranty

Orders:(504) 222-4146

24 hr. answer service:(504) 748-7090

C.O.D. VISA MCPhotronics, Inc.



Applications By Grady Pawlak

VGA To The MaxPart 1

A Look at Inexpensive Near -True Color Graphicsand Windows Accelerators

you' re probably aware by now ofa quiet revolution-or evolu-

tion-spreading throughout the PCindustry. It isn't Windows, but thelong-awaited improvements in hard-ware and software that Windows 3.0and other windowing graphical userinterfaces (GUIs) have inspired. Inte-gration gave Windows its sudden pop-ularity. Long the exclusive desktopdomain of the Apple Mac GUI, sys-tem integration under Windows sim-ply means that all applications writtenfor it essentially look and work alike.And integration goes all the way downto the hardware level.

Once Windows is configured for aparticular PC, all applications for itfollow suit. This is especially conven-ient with regard to the graphics con-troller being used. Set up Windows for640 x 480 x 256 -color resolution,and all applications within it adjustthemselves accordingly. When youupgrade your graphics card, simplyrun the Windows Setup, install the ap-propriate driver, and the next timeWindows is launched, everything ap-pears in the new graphics mode. Thismeans that Windows, by design, willtake full advantage of a given graphicsadapter, provided the appropriatesoftware driver has been installed tosupport it.

To make things even more interest-ing, most graphics -intensive Windowsapplications like PageMaker, Win-dows Paint, Ventura Publisher, Pub-lisher's Paintbrush, ImagePrep, Excel,etc., provide full support (display andediting) of 24 -bit true color image files(originally, Truevision's 24- and 32 -bitTarga formats).

"True color" refers to the fact thatthe human eye can't distinguish sub-tle differences among more than 256shades of any given color. Each pixelwithin a 24 -bit image is constructedfrom three eight -bit RGB (red, green

Truevision's TARGA + Graphics Engine.

and blue primary colors, each rangingin value from 0 to 256). This translatesinto a range of 16.7 -million possiblecolor combinations. The "possible"qualifier is used here because it wouldrequire a 24 -bit resolution of 4,096 x4,096 pixels to realize all these colorssimultaneously. Images created anddisplayed in this pixel depth appearnatural and lifelike.

The graphical PC cart is clearlyready, now what about an affordablehorse to pull it?

This month, we discuss the latesttrends in VGA technology. Nextmonth, in the conclusion of this arti-cle, we'll present a brief but fairlycomprehensive Glossary of Techni-cal Terms commonly used in videodisplay technology in general.

Evolving GraphicsRemember MDA, CGA and EGA?The same thing appears to be happen-ing to VGA, with the exception that in-stead of disappearing altogether, it's

evolving again. Originally, IBM triedto give the PC true high -resolution an-alog RGB graphics with the profes-sional graphics adapter (PGA). How-ever, its acceptance was limited large-ly because it was never really a stan-dard, it was expensive at around$2,000 and it was hardware -inefficientbecause it required two full-length ex-pansion cards to implement.

A far better solution came with thevideo graphics array (VGA) for IBM'sline of PS/2 computer systems. Pro-mising a true analog graphics solutionat reasonable cost, VGA quicklybecame an easily cloned standard thathas been greatly enhanced over thepast few years. Originally offering 256on -screen colors, or "attributes," on-ly in a very chunky 320 x 200 -pixelresolution, chip makers quicklypushed this resolution up to 800 x 600pixels SVGA (super -VGA) and be-yond by increasing the video page buf-fer to 512K and then to 1M.

Although these extended -VGAmodes were essentially proprietary


with respect to a given graphics con-troller (these non -standards are quick-ly giving way to the new guidelines laiddown by the Video Electronics Stan-dards Association, or VESA), soft-ware drivers are shipped with thesegraphics cards to provide support fornumerous popular applications pack-ages. However, recent releases of pro-grams like Windows and applicationswritten for its environment are begin-ning to make 256 -color VGA (pseudo -color) appear dated.

Unlike EGA, though, SVGA stillhas a lot of life left. Rather than dis-card SVGA in search of a new plat-form, innovative semiconductorhouses are breathing new life intowhat has turned out to be a very versa-tile approach to PC graphics.

More EnhancementsOne of the more -elegant and most -promising means of boosting the col-or performance of VGA graphics isHiColor, a registered trademark of itsdeveloper, Sierra Semiconductor. Hi -Color essentially permits existingVGA controllers to break the 256 -col-or barrier via the exclusive HiColorline of color palettes (the more famil-iar term coined by Brooktree Corp. isRAMDAC).

Simply put, the VGA palette is a de-vice with three on -chip D/A (digital -to -analog) converters and 256 bytes ofRAM used for a color attribute look-up table that provide the RS -343A -compatible RGB outputs required todrive an analog color monitor.

Industry standard VGA paletteslike Brooktree's BT471/476/478 se-ries, with which HiColor is pin -for -pincompatible, can at best produce onlyeight -bit pseudo -color. AlthoughVGA has 262,144 possible color com-binations, it's restricted to displayingonly 256 of these at any given time. Toobviate this limitation, HiColor pal-ettes cleverly bypass the look -up tableto provide pixel depths of 15 and 16bits, for 32K and 64K on -screen col-ors, approaching true -color output.

Often requiring little modificationto an existing SVGA board design,other than a video BIOS upgrade andadditional software drivers to supportthe available HiColor modes, the up-ward transition to HiColor for thegraphics card OEM is a very easy one.This translates into an inexpensive up-grade path for consumers who want to

obtain a perceived depth of color thatapproaches those of such prohibitive-ly -expensive display adapters as theTruevision 1024-32.

As of this writing, HiColor boardsare selling in the US for less than $200.Compare this with IBM's original 64color EGA (false -color), which soldfor $1,000 -plus a just few years ago!

If you still aren't convinced of themerits of such enhancements, youprobably haven't seen Windows orAutoCAD applications like Render -man and AutoShade running in Hi -Color mode.

Here's an experiment that stressesthis point: If you currently use Win-dows in a 256 -color SVGA mode, tryopening two or more windows simul-taneously with eight -bit (or greater)color images displayed within them.You'll be surprised to see all palette in-formation for the inactive windows(those still visible but with tasks sus-pended) are temporarily discarded.Only the currently active window willappear to have its correct color infor-mation. This occurs because of that256 -attribute limitation of VGA.

Only one color map (virtually theentire contents of the 256 -byte RAM-DAC look -up table) can be assignedat any given time. If two or more dif-ferent color images, each with its ownunique color map, are to be displayedsimultaneously, only one is given pri-ority over the look -up table.

Interestingly, Windows seizes a fewof the available color attributes for itsown use when launched. These confis-cated attributes are then used for col-oring icons, window borders, etc., andare no longer made available to appli-cations. Therefore, if Windows is run-ning in, say, pseudo color mode, anumber of those possible on -screencolors are lost. This isn't the case withHiColor because its viewable on-screen attributes aren't bound byVGA's 256 -color limitation.

Under the RainbowViewing a Targa image (or any 16-, 24 -or 32 -bit graphics file format) in Hi -Color mode is a real treat. Edges andcolor gradations within an image ap-pear smooth and realistic (a sort of"anti-aliasing") when compared tothe jaggies apparent in pseudo -colormodes, with a depth that 256 -colorVGA can't begin to approach.

Also gone is the obvious "banding"

that's apparent with pseudo -colorwhen viewing true -color images underHiColor. Banding is an inability tosmoothly gradate between light todark adjacent shades of a given color.Images with large areas of like shades,such as blue skies and water, readilydisplay this anomaly as strips or"bands" of stepped colors, instead ofa more realistic, smooth transitionfrom light to dark shades.

Although some color/detail-com-plex eight -bit graphics images can lookquite good, they quickly pale next to16- and 24 -bit formats with which youcan work under a HiColor-enhancedvideo system.

Proof of the increasing popularityof HiColor is evidenced by its supportin the shareware arena with Version4.6 of Bob Montgomery's perennialVPIC. Originally a GIF image -only(Compuserve's Graphics InterchangeFormat) viewing program, VPIC isnow configurable for HiColor cardsthat utilize the Tseng Labs ET4000controller and supports a broad rangeof image formats. VPIC Version 4.6lets you view and manipulate 16- and24 -bit Targa files on your PC in 32KHiColor mode, while maintainingsupport for lesser graphics platforms.

If there's a down side to HiColor,it's the fact that it can marginally slowdown graphics throughput. This is be-cause there's a lot more color informa-tion to be processed when comparedto 256 -color graphics. Just how greatthe slowdown will be depends on thegraphics controller you use with theHiColor palette. It's applicable whenin HiColor mode. In all other modes,display speed is unaffected. If thegraphics card in question makes use ofVRAM (dual -port DRAMs), the slow-ing effect of HiColor is virtually nilwhen compared to 256 -color modes atthe same resolution.

HiColor a Standard?If imitation is the sincerest form offlattery, copying the other guy's chipmeans you have a sure winner. Suchis the case with HiColor. As of thiswriting, at least one semiconductorhouse (Music Semiconductor, a Dutchcompany with a sales and marketingoffice in Colorado) has announced acolor palette (MU9C1715) claiming8-, 16- and 18 -bit color support. Itseems targeted at Sierra's HiColormarket. It remains to be seen if this


new chip will succeed.The MU9C1715 is available only in

a 44 -pin plastic leadless chip carrier(PLCC) package (industry standardpalettes are packaged almost exclu-sively in 28 -pin DIPs) and requires ad-ditional "glue" logic to implement onexisting SVGA designs. Such short-comings aren't suffered by HiColor.

VGA On SteroidsWindows and other GUIs make themost of a given hardware installationby pushing a system to its performancelimits. Minimal system memory, slowhard disks and inefficient graphicscontrollers can all add bottlenecks toWindows, making it agonizingly slowto respond to your input.

I've seen 33 -MHz 386DX-basedPCs running Windows with a poorlydesigned SVGA system and it wasnearly comedic (or tragic, dependingon how you look at it). Opening orclosing a window in 1,024 x 768 x256 -color mode was akin to using ven-etian blinds. You could actually see in-dividual strips of each window beingdrawn! Although the software driverwas probably just as much at fault as

the controller chip itself, this was anobject lesson in how power-hungryWindows truly is.

On the other side of the coin, thereare truly speedy VGA controllers likethe Tseng Labs ET4000/AX. Argu-ably the fastest non-coprocessed VGAcontroller available, the ET4000/AXperforms exceptionally well with Hi -Color under Windows. Even withoutthe added advantage of VRAM, anET4000/AX is capable of driving non -interlaced 1,024 x 768 x 256 displaysby accessing normal DRAM memo-ries in zero wait -states and providingfull support of faster throughputVRAM memories if incorporated in-to the board design.

Getting ErgonomicAlthough a Windows driver alonewon't automatically enable a nonin-terlaced 1,024 x 768 display, most ofthese boards are bundled with control-ler -specific utilities that sense when800 x 600 or 1,024 x 768 display res-olution has been invoked. They thentake appropriate action to enable non -interlacing by increasing the rate atwhich the screen refreshes.

Pushing VGA performance evenfurther are the new generation of Win-dows accelerators. Unlike true copro-cessed graphics engines like those thatincorporate a dedicated RISC proces-sor or the Texas Instruments' TI34010and TI34020 vectored -graphics pro-cessors (TIGA) familiar to high -endCAD workstations (that require a sep-arate, standard VGA controller tomaintain boot -up VGA compatibil-ity), the new Windows accelerators aretargeted specifically at GUIs.

Lacking the vector processors men-tioned above, these latest controllersare essentially built around supersetVGA cores with on -chip engines toperform rectangular bit -block trans-fers (BitBlts) and line draws, which arethe two most CPU -intensive graphicscalls in Windows and similar GUIs.

Surprisingly, these accelerators canoften outperform the TIGA cardswhen it comes to running Windows.This can likely be attributed to the factthat both approaches differ greatly indesign philosophy and target markets.While the TIGA or RISC -based plat-forms are optimized for the vectoredgraphics world of CAD, Windows ac-celerators are optimized for the raster-

141-iT1 You WE PIN: SHED YOUR. ESSA\/) Pu-r YouR, NAME oN

ri..011,*/ 1;31S K AND PASS 114E FoRWAR,t).


based, bit -map world of GUIs.By relieving the host CPU of such

mundane tasks as redrawing a window(BitBits) and its border (linear linedraws), perceived graphics speed andoverall system throughput is marked-ly increased. One of the hotrods in thisrapidly expanding field comes from acompany called S3 (pronounced S -cubed), which supports HiColor.

I recently had the opportunity towitness an impressive "Windows"demo of an S3 Carrera-based graphicscard (sans HiColor) given by a mar-keting team that really showed whatthese chips can do. Performing in1,024 x 768 x 256 noninterlacedmode, this single -chip controller (thedemo board, looking like any typicalSVGA card, with no 8514/A proces-sor) was literally snapping windowsopen and slamming them shut. Eventext writes within Windows were near-ly instantaneous. A platform like thisequipped with HiColor would makeusing Windows a very pleasurable ex-perience indeed.

The first of these S3 -based graphicsaccelerators to become commerciallyavailable is the Fahrenheit 1280 graph-ics card from Orchid Technology("1280" presumably refers to the1,280 x 1,024 x 16 Windows 3.0driver under development). Priced atless than $500 (with a HiColor upgradeto be made available), the 1280 is defi-nitely worth considering.

Another hot contender to watch foris the recently announced ET4000/X32 graphics engine from Tseng Labs.These chips are a superset of the exist-ing ET4000/AX controller with Bit-Blts in hardware (up to 30 times fasterthan block transfers performed insoftware, according to Tseng Labs),hardware line drawing, area fills andmore. The new controllers will alsosupport 2M of video RAM, providing1,024 x 768 XGA (64,000 colors) and800 x 600 24 -bit true -color (16.7 -mil-lion colors) resolutions.

Other VGA controller manufactur-ers, like Weitek Corp. with its recent-ly released W5086 engine, are current-ly planning their own graphics accel-erators, or are already in production.

Unfortunately, monitor technologyhasn't kept up with the current price -versus -performance pace of graphicscards. To take the fullest advantage ofthese cards requires relatively expen-sive multi -frequency analog monitors

that can display 1,024 x 768 (or great-er) noninterlaced resolutions with dotpitch (space between pixels) of 0.28mm and smaller. If you plan to runWindows at this resolution, don't eventhink about diagonal screen sizessmaller than 16 ". On a 14 " screen, forexample, those cute little icons becomeunrecognizable at 1,024 x 768. Andforget Windows word processing.Even with the aid of something likeAdobe Type Manager or Bitstream'sFacelift, word processing under Win-dows on a 14 " monitor at 1,024 x 768resolution is like reading a newspaperat arm's length.

A resolution of 800 x 600 is bareminimum for seeing the full width ofa standard page of text under Win-dows. Seeing even half the length ofthat same page puts you back at 1,024x 768, something that's definitely 16"territory to be usable over extendedviewing sessions.

Prices for quality 16" monitors arestill hovering at around $1,000. Is itworth it? When you consider the signi-ficant reduction in eyestrain and fa-tigue and increase in productivity viatrue WYSIWYG displays that largermonitors offer (all items that shouldbe of major concern to corporations),I'd have to say "yes." Unless you areon a really modest budget, don't evenconsider less than HiColor-equippedVGA for your next graphics card. Forjust a little more money, you can ob-tain a HiColor-ready Windows accel-

erator capable of meeting or beatingthe performance of those very expen-sive TIGA and RISC -based systemsfor bit -mapped GUIs.

Tune in next month, when we'llconclude with our Computer Graph-ics Glossary of Terms.

Companies Mentioned

Sierra Semiconductor2075 N. Capitol Ave.San Jose, CA 95132

Tseng Laboratories Inc.10 Pheasant RunNewtown CommonsNewtown, PA 18940

VPIC Version 4.6, $20Bob Montgomery543 Via Fontana No. 203Altamonte Springs, FL 32714

Brooktree Corp.9950 Barnes Canyon Rd.San Diego, CA 92121

Truevision7340 Shadeland Sta.Indianapolis, IN 46256

S3 Inc.2933 Bunker Hill LaneSanta Clara, CA 95054

Orchid Technology45365 Northport Loop W.Fremont, CA 94538

Economical8051 -BASED

SINGLE -BOARD COMPUTERS$38.00 Assembled!

(includes RS -232 interface)*Large Breadboard Area*

FREE Programming Software(a $10.00 value!)

please send check or money orderUS funds only, plus $2.75 sth:

Suncoast TechnologiesP.O. Box 5835 -CC

Spring Hill, FL 34606

CABLE TV DESCRAMBLERSTHE MOST ADVANCED

TECHNOLOGY IN CABLE EQUIPMENT:

BASE BAND JERROLD PIONEER TOD3M HAMLIN ZENITH SCIENTIFIC ATLANTA OAK

FOR OUT OF THIS WORLD PRICES CALLWORLDWIDE CABLE

1 800-772-3233FREE CATALOG AVAILABLE

7491 G5 N. FEDERAL HWY., SUITE 142BOCA RATON, FL 33487

MC / C00/ NASA No Florida Sales


Say You Saw It In ComputerCraftCIRCLE NO. 90 ON FREE INFORMATION CARD


Review By 7orn Fox

PC -Generated Printed -Circuit Boards:Experiences With "PCBoards" Software

Dozens of programs on the market let youdesign printed -circuit boards directly on aPC/compatible computer. PCBoards ($99postpaid) by Ralph A. Lindstrom may notbe the most sophisticated or advanced, butit has about everything needed to produceprofessional -quality artwork that can beused directly to fabricate at home pcboards of professional quality.

Before looking at what PCBoards cando, let's review its limitation in its latestrelease. Because it doesn't permit pad spac-ing of less than 0.1", it can't be used to de-sign a board that contains surface -mountICs that have 0.05" pin spacing. Addition-ally, board size is limited to 6.05" x 13"maximum. Since the program doesn't dooverlays, you must generate component -mounting guides by hand or with a sepa-rate general-purpose CADD program.

PCBoards doesn't come with a printedmanual; it's a file on -disk. What it doeshave is an intuitive, game -like genius. It'sgood-natured and enjoyable to work with.It's one of those well -thought-out, simpleprograms that boosts your ego by turningyou into an expert in half a day!

Despite its limitations, what PCBoardsdoes provide for the design of most pcboards is more than enough. This programis capable of producing excellent art on aHewlett Packard LaserJet II or compati-ble laser printer and can be used to designvirtually any single- and double -sided pcboards you might require.

To run PCBoards, you need an IBM PCor compatible system with at least 384K ofRAM and CGA or VGA graphics. DOSversion 3.0 or later is recommended for usewith the Shell option. While it isn't listedas a requirement, it seems foolish to runPCBoards without a color display. Amouse is nice, too, but it isn't required.

The latest version of PCBoards permitsuse of either CGA or VGA. I designed theMAG-11 single -board computer that ap-peared as a build -it -yourself project in theFebruary issue of ComputerCraft usingVersion 1.65 of PCBoards, which sup-ported only CGA. With VGA supportedin the later Version 1.7, it should be eveneasier to do because more of the board willfit on the screen.

Its obvious I like PCBoards. I'm notcompletely smitten by it, though. While us-ing this program, I discovered a few thingsI didn't like. One had to do with the

4.95

eLoadsAveZoosClearsHe 1 1Quit

rii01110

PCBoard<

a

a

011114/5

011111111111P

4111{Mt

.20. 4.95The PCBoards printedl-circuit design package has a fairly rich lineup of commands fromwhich to choose, as shown here in menu at center of screen.

u1..."Mn ' 1111/"Wrill I hi lin ......aili:.."

............r... .....r....... a .......it . gii ..,,,n, B

i is C SI=IIMir ...d!ElE73111111M

. IHP4Spamm.-="'L"ZENM=:01-1101.1.110111 1111411111101.411. 0 IMMO Mil =MINI IVII. 1.=.111111:: ..72..... ......,

i !IN= .46.41M11"4=-0.;......... -jr, mrtii: : : : :4 I: = aiimmi- i:or-iisrli immaiimi OM WINI110111 ril

164 MI MN IIIIIMINIMIIM MIMI ININIMMLIII,p4:1111111111 _Mr7f2 .....-MIMI _...a......1 Armig:lie,,argal..

U ID

ar-710 Of 3.n. 4.11 4

1111101

R. 4.

A wide range of single- and double -sided pc layout patterns can be ge.ierated with PCBoards,from very simple designs to the fairly complex example shown here.


"Text" command. A problem occurswhen trying to erase old text. By fiddlinga bit, it's possible to erase old text, but it'sclear something is amiss here. All in all, the"Text" command seemed to need a bit ofpolishing up.

PCBoards doesn't generate a ".bak"file, which can cause real problems if, in-stead of selecting "Load" from the menu,you select "save" by mistake. If youshould make this error, you'll get an au-tomatic but useless gross simplification ofyour design! Also, though the "Fill" com-mand may be bug -free, it's a bit confus-ing to use. However, judicious applicationof the easy -to -use "Thick" command cando anything "Fill" can, though it may takea bit longer to do it.

If you'd like to try out PCBoards, ademo version is available for $10, refund-able with purchase. The demo can doeverything the full-blown version can do,except save files to disk. However, severalsample file patterns stored on the demodisk can be printed out so that you cancheck for quality and compatibility withyour printer or plotter. Included in this of-fer are demo versions of an auto -router(PCRoute) and a schematic -drawing CADprogram (SuperCAD).

The positive photographic technique isthe simplest method of making printed -circuit boards using PCBoards. You canmake pc boards directly from the artworkproduced on a Laser printer. To use theartwork generated in this manner, youmust place the bottom (solder -side) art-work printed side down (in contact with theboard and top (component -side) artworkprinted side up.

I used PCBoards and an Okidata 400laser printer to design and print out the pcguides shown in the MC68HC11 SBC arti-cle referenced earlier. Laser printers willprint on suitable clear transparencies.However, some nearly transparent vellumsseem to do a better job and are easier totouch up with a pen. The main differenceis that vellum requires the UV exposurelight be left on for 10% to 30% longer timeperiod than with a transparency. Exacttime depends on the light transmissioncharacteristics of the vellum used.

To ensure solidly opaque artwork, youmust set your laser printer to maximumdarkness. Also, manually feed the vellumand set the printer so that the finished copyfeeds out the back and not the top. I'veused several different types of vellum.Most worked okay, but Micro 100% RagVellum Tracing Paper from the Dick BlickArt Catalog (Cat. No. 931218) gave bestresults. With this and GC Electronics' pos-itive-photoresist-sensitized pc blanks, I de-termined that about 15 minutes of expo-sure time to a 275 -watt sunlamp with re-

flector at a distance of 12" produced goodboards. Of course, you should always runa small sample test before attempting tomake a large, expensive board.

I detected one problem in the initialtests. The corners of thin traces didn't al-ways come out well. They sometimes lefta tiny break in what should have been asolid "foil" pattern. I repaired thesebreaks with a touch-up pen. It would cer-tainly be an annoyance if I had to repeatthis touch-up procedure every time I gen-erated pc -guide artwork. Regardless of thecause, the problem disappeared after I ranout a few later pc guides and hasn't arisensince. Perhaps my new printer had to set-tle down, as this was the first thing I triedprinting with it.

The real test came after etching. Theboard turned out nearly perfect. I detectedneither short circuits or breaks either vis-ually or with an ohmmeter.

In Brief

PCBoards, $99PCBoards2110 14 Ave. S.Birmingham, AL 35205Tel.: 1-800-473-PCBS or 205-933-1122

Dick BlickP.O. Box 1267Galesburg, IL 61401Tel.: 1-800-447-8192

NOWYOU can afford

HOME AUTOMATION!InTrol-PC provides futuristic: BURGLARY PROTECTION ENERGY MANAGEMENT FIRE PROTECTION EMERGENCY/MEDICAL APPLIANCE CONTROL

and much more for your home!Amazing NEW device you canbuild in

one evening! Construct for less than $150.00.Easy toolleas installation! Does more thansystems costing thousands! Uses IBM-PC orcompatible. Comes with POWERFUL yet

easy -to -use software that is unlike any other. Save moneyon energy; feel secure from theft, in -home assaults and fire.Enjoy the convenience of having a SMART HOME thatknows how to manage your lights, appliances, sprinklers,beating/air cazlitioning and more. AMAZINGLY simpleand ftm to build and install -wireless convenience too! Usescommon parts.PLANS and POWERFUL SOFTWAREONLY $19.95 Troops Ware

Send Check or M.O. to: POE 3079 Dept. IPCor call M.322-6875 Sparks, NV 89432-3079


HEAR THE TONES..SEE THE NUMBERS!DTMF DECODER/DISPLAY AND ASCII CONVERTER

o

1

" ..-' III 0- _

I

0 I

I:-I

I:-I

I

-II

I

- 3

I-I

I

:II- 0

Mode TDD 8 de odes and di plays all 16 DTMF digi s andprovides an ASCI seem output. Digits are displayed on eightLED's. 32 character buffer can be scro led. It will acceptalmost any audio source such as a tape ecorder, telephoneanswering machine, scanner, etc. Perfect for remotecomputer data entry using a telephone keypad. Serial outputcan be connected to your computer. IBM compatible softwareincluded for displaying, storing/printing time, date and numberfor automatic logging. Assembled/tested circuit board, ready touse! 30 day money back guarantee!

VISA/MC ACCEPTED

TDD-8 DTMF DECODER/DISPLAY/ASCII $99.00CAB -1 AUDIO & COMPUTER CABLES $20.00PS -12 110VAC TO 12VDC POWER PACK $10.00PMR-1 PLASTIC MOUNTING KIT $15.00

Add $5.00 S/11 USA/Canada, $10.00 foreignMoTron Electronics, 310 Garfield St, #4

Eugene, OR 97402ORDERS: 800-338-9058 (USA/Canada)INFO: 503-687-2118 FAX: 503-687-2492


Affordable 8031 DevelopmentSingle Board Computers, Assemblers, Compilers, Simulators, and EPROMEmulators. Ask about design and manufacturing services for your product!

The Control -R series of singleboard computers make prototypingand one -of -a -kind projects easy andaffordable. Both feature 8K EPROM,RS232 port, Port 1 & 3 access plus:

Control -R Model 1 $49.955v dc operation, 3"x4", assembled.

Contrl-R Model 2 $79.95Model 1 features + 8K RAM and ex-pansion bus. 3.5"x4.5"

8031 "C" Compiler $200.00

Full featured K&R style C develop-ment system includes compiler, as-sembler, linker, documentation andcomplete library source code. Highlevel language plus in -line assem-bly code gives you the best of bothworlds. 5 memory models allowcode generation for any 8031 de-sign-even those with no externalRAM! MSDOS 360K disk.

Cottage Resources CorporationSuite 151, 10271 South 1300 East

Sandy, Utah 84094 USAVISA/MC, COD. Call to order: (801) 269-2975

Say You Saw It In ComputerCraft



Fitting More Power into Windows

A new column, GUI Guts, makes its debutthis month. In each issue, it will offer tips,tricks and applications that increase theproductivity of graphical user interfaces(GUIs). Microsoft Windows will receive alion's share of the attention here-so longas its momentum leads the other GUIs. Butother alternatives will be covered as well.Readers are invited to correspond withquestions about, or favorite tips and tricksfor, their favorite GUIs.

It doesn't take much effort for a DOSpower user to become a Windows poweruser. The mark of a power user is an abili-ty to extend into the full capacity of thecomputing environment. It means know-ing the tools and how to use them. WithDOS, it's intimately knowing the grit andsmell of hordes of commands. With themore intuitive GUI interface, such depthis somewhat de-emphasized, and the pow-er user's acumen can be transferred to agreater breadth of applications. It's notsurprising, therefore, that power userstend to collect tools like suburbanites col-lect at a Sears fire sale.

Such power users are likely to find Mi-crosoft Windows a cramped environment.As more and more applications areopened, the desktop becomes so clutteredthat, soon, most windows are likely to beiconic. Congestion is only likely to getworse. Version 3.1 is expected to lift cer-tain restrictions imposed by the current im-plementation of Windows and support afar greater number of applications.

Fortunately, keeping all those applica-tions open and readily productive isn'thopeless. If you've got the right Windowsutilities, it's possible to open an enormousnumber of applications-simultaneously-without having them chock-a-block, oneupon the other.

All of these utilities work their miraclein much the same way: by providing Win-dows with a virtual desktop. This is essen-tially a workspace that's some multiple ofyour monitor. With a virtual desktop, youcan conveniently fit your contact manager,calendar, spreadsheet, word processor,database and everything else into Win-dows. It's also possible to quickly jumpamong several applications sharing thesame data. A spreadsheet, charting pro-gram, presentation program, word proc-essor, and desktop -publishing programcould all be open-sharing a chart and

This is Windows

This is Windows wiih

Guardian Utilities (GU)

Zeus Microsystem's "Guardian Utilities" opening screen under Windows.

underlying data-with instant access to theformatting, editing and publication toolsin each application.

Windows doesn't know when a virtualdesktop is installed, and neither do the ap-plications. The utilities create and managethe workspaces with desktop maps that letyou move applications from area to area.The maps also let you move your displaybetween areas-something like the wayscroll bars let you move over large docu-ments within an application window.

Guardian UtilitiesA simple example of these tools is the "vir-tual large desktop" in the Guardian Utili-ties (GU). It's two -by -two configurationis fixed, but GU, alone among workspace -clone artists, allows you to move from areato area by simply moving your cursor. Youcan also move around with hot keys or itsdesktop map. Its map does lack the abili-ty to follow active applications or float tothe top of active Windows, but you canswitch to any area without regard to the ex-istence of applications there.

GU includes other utilities, such asscreen notes, a screen saver and animatedwallpaper. And although GU lacks a fewluxuries, such as automatic installation,it's a solid product that, at $19.95, costs

less than many shareware programs. Any-one can afford to experiment with it.

Amish UtilitiesBig Desk is shareware. However, it's beenincorporated into a commercial productcalled Amish Utilities that will ship inApril. You can try the shareware, but AUis where development will continue, andas part of the collection, Amish Desk (asit's now called) has been modified and in-tegrated with other utilities. It has a com-mon look -and -feel and shares a commonDLL library with an applications launcherthat can serve as the Windows shell, quitesophisticated screen notes and on -screenstatus monitors for memory and clockfunctions.

Amish Desk (AD) lets you select up to64 areas that are easily navigated via itsdesktop map. The map, or its icon, can bemade to follow the active application andstay on top (float) of other windows.

Versions of AD are already in develop-ment for OS/2 and NT. So AD will havean early advantage for multi -platformGUI environments. (In fact, if you're go-ing to Windows World in Chicago, presi-dent Ted Matsumura promises that you'llbe able to see it running on NT in theMicrosoft booth.)


rnmdrul

1,1,4AN "<AI I 15/wortfil,1 iJeentl I. I 411 4 '1

15,,r, Al I 1, I

4 1 1

*MI.JJJJ.

e

The main menu of hDC's Power Launcher utility, shown at left, includes aVirtual Desktop Map. The screen at the right is an example ofthe utility's PowerApps screen.

Power LauncherThis utility package from hDC includes anadvanced launcher and four utilities:screen saver, keyboard macros, mousemacros and floating toolbox builder (moremacros). Its virtual desktop is part of thelauncher, as is the screen saver, and it isvery slick. You can even have applicationsautomatically open to exact sizes at specific

locations on each desktop area. Navigationis through the desktop map-the only oneof these maps in a sizable window. It canproduce up to 64 desktop areas, and hasboth follow and float features. I wouldn'tbe surprised if it shared some core technol-ogy, or development staff, with AD.

The Power Launcher and toolbox build-er, though, are all on their own. It's the

depth of these applications that really setsthis utility apart. Nothing else has theirautomated macro -generation buttons anddialogs. They also have a recorder, and forhacking, there's complete documentationof the macro -language's syntax and se-mantics. Yet while "Power" is far froma misnomer, it doesn't take a Ph.D. in Cto figure it out, either. Despite its one or

8031 PROGRAMMABLE CONTROLLERBOARDS

Common features: 8031 AH CPU, 11.0592 MHz clockspeed, User interface is via a terminal emulator programrunning on a host computer and linked through the RS232Serial Port on the controller board.

32 K FLASH MEMORY{Eliminates the need for Programmerand UV Eraser}

16 K EPROM and 8 K RAM 32 Buffered I/O lines

Assembled and Tested board $ 155DG32F Board (4.80"x6.00')

16 K EPROM and 8 K RAM 32 Buffered I/O lines

Assembled and Tested board $129 >DG31 Board (4.5"x5.5")

On board 8 or 16 K EPROM,8 or 32 K RAM capacity

Ports 1 and 3 processor lines on 20 pinheaders, I/O expansion lines on 20 p.headerAssembled and Tested board $ 80

EMC32 Board (3.00"x4.00")

KITS, Power supplies, Support and Application Software available.

L.S. ELECTRONIC SYSTEMS DESIGN2280 Camilla Rd. Mississauga, Ontario, CanadaL5A 2J8 Phone/Fax: (416) 277-4893

Terms: Shipping US/Canada $ 6 Check or Money Order, Please

RECESSION BEATER!Would you spend $19.95 to save $35.00on software and computer accessories?

And own it with a warrantee on quality?Retail Price Your Cost

Silent Service II 59.95 36.27 F-15 Scenario DiskOperation Desert Storm 29.95 18.13

AND MORE! YOU SAVE... 3550

THERE'S LOTS MORESoftware

IBM PC / Compatibles Nintendo / Super Nintendo Mac / Mac II Amiga Atari ST Commodore C-64 Apple II / Apple II GS Sega / Sega Genesis

SAVINGS ON:Hardware Joy Stick Mouse Lap Tops Monitors Keyboards Modems And More!

AND MORE!

For a lifetime membership and color catalogSend 19.95 & 3.00 (S&H) to:

SOFTWARE+610 Liberty Street

Salisbury, Maryland 21801 (410) 860-8252

1ST 1,000 WHO MENTION THIS AD GET A FREE GIFT!


73

SuperSitePrograms it All!

for only $895

PLD,GAL,Micro,PROM,EE/PROMGet the best software based 40pin-device programer today

and receive a FREE CUPL Starter Kit

14 Day Money Return Policy.

For more information

Vail Silicon (305) 978-6083


CABLE TVDESCRAMB LERS

1-800-582-1114FREE CATALOG

GUARANTEED BEST PRICES IMMEDIATE SNIPPING

M.K. ELECTRONICS8362 Pines Blvd. Suite 276Pembroke Pines, Fl 33024

LaserPrinterToner Cartridge

Recharging Earn up to $125/hr at home$30K - $250K income possible Huge market - less than 15 in 100cartridges were recharged last year

Low -Cost, high -quality videotapeand "Hands-OW1rainingAlailable

Complete training package -Mmonly $595 - $995! (None -higher)

No supply contact requirementsor on -going franchise fees

All supply sources fully disclosedAsk aboutthe "Business in a Box"100% Money -Back Guarantee!Call for details & DEMO VIDEO

1-800-527-3712The Laser Group, Inc.223 Palmer Court De Kalb, IL 60115 (1-815-748-5823)

two flaws-an occasional minor instabilityand an annoying copy -control installation-Power Launcher unquestionably givesyou the most bang.

WideAngleWideAngle is neat. There are enough op-tions to customize it for any taste I can im-agine, even the kinky ones, within its fixedthree -by -three configuration. (Of course,I know of these uses for Windows onlysecond-hand.) Its X-ray view, for instance,lets you see all of the apps in an area at thesame time. You can move icons across areaboundaries in the desktop map, thoughyou can't directly drag windows betweenareas. You can automatically open ap-plications in a particular desktop area also.

WideAngle is powerful but moderatelycomplex if you want to take advantage ofits full power. Hot keys will navigate theworkspaces, or bring specific windows intothem, only if you program them. You canalso create up to nine different "groups"that can be used to open applications whenWideAngle starts. Naturally, this requiresconfiguration. It also requires use of morethan a single menu. Nevertheless, althoughit's not as intuitive as I'd like it to be, Wide -Angle lets you use its basic features easi-ly. Its map will follow you around. It'llfloat over other applications, too.

MoreWindowsThere's one more utility that provides a vir-tual desktop. However, it does it in a verydifferent way from the rest. MoreWin-dows is actually a special set of drivers; aprogram that makes it possible to installthem. (The Windows Setup program canreturn to any other driver. So, I suspectthat requiring an installer is simply an in-nocuous form of copy control.) Since it'simplemented as a driver, MoreWindowsdoesn't clone the desktop area. Instead, ituses more pixels as would a larger monitor.Rather than several workspaces, it pro-vides one large one. Unexposed areas moveinto view as the cursor approaches them.

The great advantage of MoreWindowsis that, because it works like a largermonitor, applications can display largerwindows. PageMaker can display a fullpage or a pair of pages side -by -side, de-pending on the model you select. (Thereare four for EGA and five for VGA.) In-stead of using scroll bars that require ap-plications to tediously re -draw parts of thescreen, you can instantly move back andforth over whole pages.

As far as applications are concerned, theother virtual desktops provide additional,not larger, workspaces. Applications don'tget any larger than usual, and you're leftscrolling documents as you would normal-

ly. However, you can conveniently useMoreWindows with all of the other virtualdesktops, except WideAngle. Guardian isalso somewhat less efficient with More -Windows. (Their maps don't compensatefor the change in scale and, consequently,grow unwieldy.)

The only drawback is that the currentversion of MoreWindows uses only a VGAgraphics mode for its virtual output. Itdoesn't support either 256- or true -coloradapters. Nor will it drive a monitor atmore than 640 x 480 resolution. (Inciden-tally, for those in the know, while thedocumentation for all these products wasat least satisfactory, the brief but im-pressive MoreWindows manual was doneby none other than Daniel Will -Harris.)

Nonetheless, wrap your eyes around anyof these tricksters, and you'll soon bedisplaying more applications than everbefore. Use the cloners for high -resolu-tion, high -color paint or drawing pro-grams. Use MoreWindows for page -layoutin word processing, desktop publishing,spreadsheet publishing and forms design.Even use them in combination to displayseveral layouts at once. But watch out, youmay need to get some suspenders for yourtool belt.

Amish Utilities, $99.95Amish Software1325 Mills St., No. 1BMenlo Park, CA 94025Tel.: 415-323-4627


Power Launcher, $99.95hDC Computer Corp.6742 185 Ave. NERedmond, WA 98052Tel.: 206-885-5550


More Windows, $99Aristosoft6920 Koll Center Pkwy., Ste. 209Pleasanton, CA 94566Tel.: 510-426-5355


Guardian Utilities, $19.95Zeus MicrosystemsBox 6143San Rafael, CA 94903Tel.: 800-727-2603 or 415-491-1737


WideAngle, $129.95Attitash Software20 Trafalgar Sq.Nashua, NH 03063Tel.: 800-736-2803 or 603-882-4809




The Software Toolworks "Miracle PianoTeaching System"

Did you have to take music lessons whenyou were a kid? I remember taking pianolessons when I was seven or eight and, likemany kids, disliking them intensely. Notonly were the endless scales boring and dif-ficult to master, but having to walk severalblocks every day to use a family friend'spiano on which to practice just added in-sult to injury. As you might imagine, likea lot of kids who had piano lessons foistedon them, I soon talked my parents into let-ting me free from the "piano tedium."

As an adult, now I wish I hadn't beenso successful in weaseling out of my les-sons. Over the years, I've picked up somefacility in chording on a guitar, but despiteseveral false starts in trying to learn pianoby myself (remember those old advertise-ments for a mail-order music course thatstarted out "They all laughed when I satdown at the piano.."?), the $30 to $50 anhour cost of piano lessons, along withhours of tedious practicing of scales andhand exercises, have kept me far from acareer as a piano virtuoso.

Perhaps it's this frustration that has me,as a parent of four, wanting my kids tolearn a musical instrument. But with myhoard, technology might make learning amusical instrument a great deal easier. Anoutstanding example of an educational useof a PC is the Miracle Piano Teaching Sys-tem from The Software Toolworks.

As its name implies, the Miracle PianoTeaching System (MPTS) is somewhatmore than just another electronic musicalinstrument. As with any system, it consistsof several components. Two are physical:an electronic keyboard and software forwhichever system with which you're usingthe MPTS (it's available, or soon will be,for IBM, Amiga, Macintosh, NES andSuper NES computers). The last, and prob-ably most important part of the system issomewhat more metaphysical-a very clev-erly crafted and well -thought-out and im-plemented approach to teaching the basicsof playing piano and sight-reading music.

I first saw the MPTS demonstrated atthe Fall 1990 COMDEX show in LasVegas. At that time, the Toolworks wasjust getting ready to introduce the firstmodel, which worked in conjunction withthe Nintendo Entertainment System (NES).A cable from the Miracle was plugged in-to the first controller socket, and theMiracle program cartridge plugged into theNES control deck. You followed the pro -

M 1 RAC LE,AHD TEACIMIG SYSTENI

1

gram on your TV receiver and used the sec-ond game controller to advance screens aslessons progressed.

At that time, it knocked me out; so I im-mediately requested a review unit, hopingto become somewhat familiar with the sys-tem until the PC version was ready. Unfor-tunately, none of the three units 1 triedworked reliably, and the quality of the TVimage was, at best, poor. I can't blame thison the Miracle, as games played on ourNintendo also tend to take a sharp left turnfrequently (with four kids in the house, I'msurprised when things do work reliably!).

The Miracle enjoyed some modest suc-cess that Christmas season. For the holi-days that have just past, the Toolworksfinally had the PC version ready and instores. I decided to take another look, andI'm glad I did. It was worth the wait.

The KeyboardObviously, an important part of any sys-tem that purports to teach one how to playthe piano is a keyboard. Some home -studycourses assume you have a standard pianoor an electronic keyboard available, butthe Miracle's keyboard, though it doesn'tlook it, is a bit different from what you canbuy in a department or music store.

At first glance, the Miracle keyboardlooks very much like any generic Casio,Yamaha or other electronic keyboard sell-

ing in the $250 price range, though it hasfar fewer buttons than most department -store bargains. The keys are just aboutstandard size, and the 31 /2" long by 13 "wide case contains 49 of them instead ofthe standard 88 keys normally found on afull-size piano. The missing octaves on thetop and bottom won't really make any dif-ference in your learning how to play. Bythe time you get to the difficulty level wherethey're important, you're far beyond whatthe Miracle System has set out to teach.

The big differences in this packagearen't apparent from a casual glance at itscontents. Firstly, just like with much moreexpensive keyboards, the keys are veloci-ty sensitive so that the harder you pressthem, the louder the sound obtained. Astandard mechanical piano has asomewhat different feel, but it operates ex-actly the same way-pound the keys forloud music, gently press them for softernotes. Also, like many of the better elec-tronic keyboards, the Miracle is a MIDIdevice. MIDI is a specialized form of serialnetwork that was developed specifically tolink electronic musical instruments witheach other and with computers.

As with any MIDI device, the Miraclecan control, and be controlled by, otherMIDI devices. Eight innocuous rockerswitches can be used to select the "patch,"or instrument voice, as well as control vol-


PC BOARDSTed Needleman

24 hr. d.s./72 hr. m.l. Prototype to Production

FR -4, Plated-Thru Teflon, UL Recognized

VI I. M. P.A. C.

Call us for an instant quote24 -hr. modem for easy transfer of

Drill & CAD Nes.Free Tooling On First Order!

Superior Quality at Competitive Prices!

CAPITAL ELECTRO-CIRCUITS7845-J Airpark Road

Gaithersburg, MD 20879(301) 977-0303

Fax: (301) 990-6715


B.S. & M.S.In Computer Science ALL COURSES BY CORRESPONDENCE Increase your earning power

AMERICANINSTITUTE

COMPUTERSCIENCES

Join students from leadingcomputer companies

Ada course availableFor free information call1-800-767-2427

B.S. & M.B.A.In Business AdministrationA Chadwick University degree program can help youachieve a more successful future: B.S. and M.B.A. programs in Business Administration. ALL COURSES BY CORRESPONDENCE Join students from Fortune 500 companies. Increase your earning power.

Call for our free bulletin:1-800-767-2423 UNIVERSITY01991 Chadwick University

POST CODE MASTERDebug PCs, Using Built in

Power On Self Test (POST)O Listings and database

111

for major BIOS types0 Power Supply LEDs For IBM AT & comp-atibles including Compaq0 Only $59.00

PORT TESTPC Serial/Parallel PortDiagnostic Software.

0 ComprehensiveDiagnostics and Utilities0 Universal Loopbackplug Included0 Identify AddressesCI Only $89.00

.M

064.VSDI(408)296-4000

MicroSystema Development4100 Moorpark Avenue, 0104San lose, CA 95117

Fax: (408)296-5877

ume level when the Miracle is being usedin its stand-alone mode.

The Miracle contains 128 different in-strument sounds, including various piano,organ, guitar, bass, percussion and wood-winds. These patches are detailed in oneof the two manuals that accompany thesystem. They can be selected from the topswitches, another MIDI device or a com-puter -controlled sequencer package. Thekeyboard is 16 -note polyphonic. That is,you can play 16 different notes at the sametime, and the keyboard can be split so thatthe top and bottom halves are different in-strument patches.

Sound emerges from two top -mountedstereo speakers (which sound pretty good),or it can be routed through an audio ormusical instrument amplifier. There's a setof stereo phono jacks on the unit's backpanel. The Miracle keyboard has an addi-tional DB-25 connector beside the MIDIport for connecting the keyboard to a com-puter or game system. Though it's notdetailed in the documentation, the extraDB-25 connector provides access to a fairlystandard serial port.

Finally, unlike many lower -end key-boards, the Miracle doesn't run on batterypower. You must use a supplied ac powersupply. To top off the Miracle package, theToolworks includes earphones, a foot ped-al made of conductive rubber that you useas a damper pedal or instead of the mouse/space bar to advance the lesson and a spe-cial serial cable to attach the keyboardto your PC.

The SoftwareThe second physical component of theMiracle Piano Teaching System, and themetaphysical basis that makes the systemwork so well, is the supplied software. In-stalled from two 1.2M 5 1/4 " or three 720K3 " diskettes, the software is both interac-tive with the keyboard and adaptive. Inci-dentally, while the software isn't copy pro-tected, it's in a compressed format. Soft-ware Toolworks recommends backing upthe installed software, rather than copy-ing the disks.

The two keys to the software's utility arethe degree of its interaction with the key-board and the way it adapts the lesson planand presentation as a result of thisinteraction.

When you enter the program, you arepresented with an overhead view of a"music school." The different rooms de-fine different activities you can perform.The first stop is "Administration," where,you register yourself as a student (so thatthe system can keep track of multiple us-ers), set preferences (like which serial portyou're using and whether you want to usethe foot pedal to advance the screens) and

print out certificates of completion as youfinish each of the 36 lessons that comprisethe course. The other rooms are the Class-room, Practice Room, Performance Hall,Arcade and Recording Studio.

Most of your time will be spent in theClassroom, Practice Room and Arcade. Inthe Classroom, lessons are presented on a"chalkboard," and you are asked ques-tions and encouraged to try out what's be-ing presented. As you progress through alesson, you play along with a screen presen-tation while your performance is analyzed.

For more formal practice, you move tothe Practice Room, where you can selectfrom a variety of pieces at each lesson level.Finally, when you're comfortable with apiece, the Performance Hall lets you playwith accompaniment from the ToolworksOrchestra (the computer plays the other in-strumental parts through the Miraclekeyboard).

The Arcade lets you practice vital skillsthrough clever games. For example, theshooting gallery has you knock off ani-mated ducks swimming along the trebleclef by hitting the correct note on the key-board. Likewise, chords are practicedin the Ripchord game. If your preferenceis to just listen to the Miracle play, theJukebox can be set to play any piece that'scontained in the lessons with full orches-tral accompaniment.

Finally, there's the recording studio,which is actually a pretty neat eight -tracksequencer that lets you record and playback your own compositions. I playedaround with it a bit, but to really get anyuse out of the Recording Studio, you haveto get a bit further along in the lessons.

Having gotten at least somewhat famil-iar with the NES version of the Miracle,I was impressed with just how much bet-ter the PC version is. Obviously, becausethe PC has a much greater program space,the software can be more sophisticatedthan what can be contained in a NESROM/game cartridge. The NES versionleaves off such niceties as the ability totrack multiple users, the Recording Studioand the Jukebox. The graphics on the PCversion are also vastly superior, especial-ly when viewed in VGA mode.

The basic adaptive technology used isthe same in all versions of the MPTS. Thesoftware monitors the keyboard as you gothrough lessons and exercises, noting ifyour timing is off, whether you're hittingthe correct notes and if you're pressing thekeys with the correct amount of pressureand releasing them too soon or holding thenote too long. It uses this information todetermine how rapidly you should be pre-sented with the next technique or if youneed more practice. And it never gets im-patient or annoyed with you.



Of course, if you think you need morepractice in an area, or you're not sure youunderstand something, you can back up asfar as you'd like to or simply repeat pastlessons. You can also jump ahead shouldyou wish to do so. I've seen a lot of CAI(Computer Assisted Instruction) over theyears (in fact one of my first program-ming jobs more than two decades ago wasin this area), and the Miracle system is oneof the best -implemented CAI applicationsI've ever run across.

Is It Really a Miracle?Not really, but it comes very close to be-ing one. Let's face it, there's no "miracle"way to learn how to play any musicalinstrument well. To become proficient inanything, playing piano included, takeslots of practice and a fair amount of time.The MPTS suggests that it should takeabout six months to complete the lessonsand that you should try to use the systemfor 45 minutes to an hour a day. In the realworld of human teachers, this is about thesame amount of time you'd be spendingpracticing, though it's possible to pick upthings a bit faster with the excellentorganization and approach the Miracleprovides. With a little applying yourself,you'll be playing simple two-handed pieces

in one to three weeks. And when theMiracle orchestra accompanies you, even"Mary Had a Little Lamb" sounds good!

At the same time, it's work to practiceso much. After 30 or 40 minutes on theMiracle, my hands ache. It makes practicea lot more enjoyable, though, especiallywhen compared to the dry rote method ofrunning scales still extensively used inteaching piano. But you still need to prac-tice to become proficient, even if it takesthe form of shooting ducks off the scalein the shooting gallery.

While the software does a good job ofevaluating your performance, it doesn'thave quite the insight that a good humanteacher has. For example, it can't really de-termine if your hand positioning needsmore work, if you're actually using theright fingers on the key or if your eyeglassesneed cleaning.

At a retail price of $479 (for the PC ver-sion), the MP TS costs less than a fewmonth's worth of a decent piano teacher'svisits and is available when you are. Severalavailable "music packs" add lots of addi-tional practice pieces, should you masterall of those included with the system. Thesystem's game -like approach makes thethought of piano lessons a lot less threaten-ing to your kids, should you be consider-ing the unit for them rather than yourself.

In the final analysis, whether the MiraclePiano Teaching System is worth the pricedepends on whether or not you (or yourchildren) will stay the course. There's noeasy way, but the Miracle Piano TeachingSystem does make learning to play thepiano a lot less painful.

I frequently like the products I reviewin this column, but in the more -than -fouryears I've written this column, therehaven't been all that many products onwhich I'd spend my own money. I'd likemy oldest to get about a year older beforeI get my own Miracle so that he won't haveso much difficulty because of his smallhand span. But I had so much fun with thesystem while reviewing it, I don't know ifI'll have the patience to wait.

If you've always wanted to surprise yourfriends by sitting down at the piano, givethe Miracle Piano Teaching System a goodhard look. It just might be a fun way to go.

Miracle Piano Teaching System, $479.95(IBM PC version)The Software Toolworks60 Leveroni Ct.Novato, CA 94949Tel.: 415-883-3000


ELECTRONIC ENCLOSURES

Everything to complete your project -From initial concept to finished product!

Rack Mount Universal Split Case

Complete line of Enclosures in Aluminum, Steel or ABS,Hardware, Silkscreening, Tools, Custom FabricatingCall for our FREE Full Color Catalog(800) 800-3321 or (216) 425-8888 (216) 425-1228 Fax

Cage & PreampEnclosures

Knobs & Parts

ABS

Project Pro)

Linear

1710 ENTERPRISE PKWY. TWINSBURG, OHIO 44087

DON'T REINVENT!USE OUR MICROCONTROLLER BOARDS

We have done the tedious job of getting theprocessor, memory and serial port working. Youcan spend your time on more creative designs.

We sell low cost 80C32 microcontroller boardswhich are ideal for quickly developing products,prototypes or test fixtures.

Breadboard area and expansion connector 12 application notes included Software tools available from BASIC to a

Multitasking System Call for a quote on custom designs.

Iota Systems, Inc.FOB 8987 Incline Village, NV 89452

PH: 702-831-6302 FAX: 702-831-4629

CIRCLE NO. 69 ON FREE INFORMATION CARDCIRCLE NO. 72 ON FREE INFORMATION CARD

Joseph Desposito

A New Neuron Chip, Multiple Array MatrixEPLD, New NEC Microcontrollers and aDual RS -232 IC

Companies come out with breakthroughtechnologies almost as fast as we can reporton them. This column highlights a newneuron chip from Motorola and a newMultiple Array Matrix EPLD from Altera.

Neuron ChipMotorola's (MOS Digital -Analog Inte-grated Circuits Div., P.O. Box 6000, Aus-tin, TX 78762) newly -announced MC -143150 Neuron Chip is an intelligent con-troller capable of running Echelon's LON-Talk Protocol. The Neuron Chip is theheart of LONWorks-based intelligent dis-tributed control applications. This chip isbased on a multi -processor architecturethat contains the complete seven -layerLONTalk communication protocol infirmware.

In the LONWorks technology environ-ment, the chip can support communicationover a variety of media, including twistedpair, power line, fiber-optic, radio fre-quency and others.

Motorola is also licensed by Echelon tosell to its customers the LONBuilder Devel-oper's Workbench. This is a comprehen-sive set of tools for building LONWorks-based intelligent distributed controlapplications.

In support of LONWorks, Motorolahas placed LONBuilder development toolsand trained application engineers in salesoffices across North America. With LON-Builder tools and engineers in the field, thecompany expects to provide any level ofsupport for both hardware and softwareinquiries relating to LONWorks.

Motorola also provides an extensive lit-erature package that's available throughthe field sales offices. Order under partnumber LONPak/D.

Among the technical features of theNeuron Chip you'll find:

Three eight -bit pipelined processors forconcurrent processing of application codeand network packets An 11 -pin I/O port that's programmablein 24 modes for fast application programdevelopment Two 16 -bit timer/counters for measur-ing and generating I/O device waveforms A five -pin communications port thatsupports direct connect and network trans-ceiver interfaces 1,024 or 2,048 bytes of static RAM for

buffering network data and storing net-work variables 512 bytes of EEPROM with an on -chipcharge pump for flexible storage of addressand binding data An external memory interface to supportlarge application programs A sleep mode to reduce power con-sumption A unique 48 -bit ID number in every de-vice to facilitate network installation andmanagement.

Price per Neuron Chip in 1,000 -piecequantity is $11.78. It's available in a 64 -pinquad flat -pack.

Multiple Array Matrix DebutsAltera Corp. (2610 Orchard Pkwy., SanJose, CA 95134) has introduced the firsttwo members of its Multiple Array matriX(MAX) 7000 family of high -density, high-speed erasable programmable logic devices(EPLDs), the EPM7256 and EPM7032.

The EPROM -based EPM7256 has 256macrocells and provides a 70 -MHz in -sys-tem clock rate. The device has 164 user I/Opins and 10,000 available gates, providing5,000 usable gates in most logic designs.This makes it a good programmable alter-native to gate arrays. The EPM7256 is of-fered in a 192 -pin erasable, windowed cera-mic pin -grid array (PGA) package. A208 -lead quad flat pack (QFP) version willbe offered in mid -1992.

The 32-macrocell, 44 -pin EPM7032 isAltera's first EPLD manufactured onEEPROM technology and reveals a strate-gy to expand MAX 7000 technology offer-ings from EPROM exclusively to EEPROMas well.

Because MAX 7000 architecture is tech-nology -independent, the EEPROM-based, 44 -pin EPM7032 shares the sameadvanced architectural features as theEPROM -based EPM7256. Structurally,the only difference is that the EPM7032uses EEPROM transistors to construct itslogic arrays, whereas the EPM7Z56 usesEPROM transistors. In use, the only dif-ference the device user will notice is howthe part is erased. With EPROM, UV -en-ergy is used, and with EEPROM, an elec-trical pulse replaces UV energy.

Offered in an erasable, plastic leadedchip carrier (PLCC), the logic density,12-ns logic delays and 83.3 -MHz in -system

performance of the EPM7032 make it well -suited for integration of multiple PAL orGAL designs or the implementation ofcomplex state machines, counters, decod-ers and other glue -logic functions.

MAX 7000's architecture differentiatesitself from other EPLDs and FPGAs byutilizing a Programmable Interconnect Ar-ray (PIA) that provides a single, uniformsignal delay between any two logic ele-ments on the device. Unlike cumulativeand variable logic delays inherent in gatearrays and channel -routed FPGAs, thePIA in MAX 7000 gives predictable per-formance without significant signal skew.In addition, MAX 7000's macrocell archi-tecture provides fast parallel and flexibleshared logic expanders to support efficientimplementation of logic. The result is aunique combination of high performanceand usable density that fits the widest rangeof logic applications.

The entire MAX 7000 family of EPLDswill be supported by Altera's MAX+PLUS II software available on PC andworkstation platforms. On the PC, Alteraoffers a complete Windows 3.0 -based de-sign system including schematic, text andwaveform design entry, as well as automat-ic logic synthesis and design partitioninginto multiple EPLDs. Available designverification options include a full timingsimulator, timing analyzer and delay pre-dictor.

For Sun and HP/Apollo workstationplatforms, Altera offers the MAX + PLUSII compiler with industry -standard elec-tronic design interchange format (EDIF)netlist input and output to effectively workwith standard CAE tools from Cadence/Valid, Logic Automation and MentorGraphics.

The EPM7256GC192 is available in sin-gle unit quantity for $395, and the EPM-7032LC 44 is priced at $14.75 in 100 -piece quantity.

Eight -Bit MicrocontrollersNEC Electronics (401 Ellis St., P.O. Box7241, Mountain View, CA 94039) has add-ed five new microcontrollers to its high -endK2 family. The eight -bit single -chip prod-ucts feature increased memory sizes andsophisticated control of peripherals via aMacro Service Transfer Facility providedby a Peripheral Management Unit within


RRIN

RAIIN

ENRA

RA1OUT

ROUT

FIROUT

RA4OUT

FIROUT

TA1IN

WIN

TA3IN

TOP VIEW

0 g s s

CI 1111 CI CI 1:11

IDIO0m

Im

Im

MAXIMMAX249

mmmE!! M II Mo

>' LI)CO.(3

PLCC

lz

MAX249 Functional Description

10 Receivers5 A -Side Receivers5 B -Side Receivers

6 Transmitters3 A -Side Transmitters3 B -Side Transmitters

4 Control PinsEnable Receiver A -Side (ENRA)Enable Receiver B -Side (ENRB)Enable Transmitter A -Side (ENTA)Enable Transmitter B -Side (ENTB)

+5V

11.1f

21

lg4 C1+ Vcc

Cl +5V TO +10V VOLTAGE DOUBLER

24C2+

26

10* 1gC2 -+10V TO -10V VOLTAGE INVERTER

18 ENTA ENTB 27

INGOT +5V +5V Te1OUT 44

15 TRIM 11111N 30

El RRIN

El Re2IN 2 TROUT +5V +5V TROUT 43

El ReilN 400k

ENRB16 TRIM TB2IN 29

3 TROUT +5V +5V THOUT 42Fri ROUT

El ROUT

rru Re3OUT

R84OUT

17 TA3114 TeeN 28

Re5OUT 8 RAtIW RBA 37

TelIN5k

_

5k

El T821N10 RA1OUT FtiOUT 35

7 RA2114 Re2IN 38

g2

5k 5k

11 RA2OUT Re2OUT 34

RRIN 39

5k 5k

12 RROUT Re3OUT 33

5 RA41k...___<,_ RB4IN 40

I -5k 5k

13 RA4OUT Re4OUT 32

4 BASIN R85IN 41

5k 5k

14 RA5OUT R55OUT 31

9 ENRA (NOB 35

GND

119

Fig. 1. The MAX249 transceiver has six RS -232 drivers and 10 RS -232 receivers that make up two complete Data Terminal Equipment(DTE) serial ports on a single chip.

the CPU. The five new products are theµPD78217A, µPD78218A, µPD78237,µPD78238 and APD78P238.

K2 is an eight -bit family of CMOS mi-crocontrollers that are designed for real-time embedded control applications.NEC's K2 family offers large on -chipmemory capacity, including products withup to 32K of ROM and 1K of RAM. K2members can address up to 64K of pro-gram memory and 1M of data memory.Operating at 12 MHz, K2 devices executetheir fastest instructions from internalROM/PROM in just 333 ns, or externalmemory at 500 ns.

All K2 products include the patentedMacro Service Transfer Facility that great-ly reduces the interrupt load on the CPUby handling many of the repetitive service

requests that normally require the CPU toexecute a time-consuming interrupt serviceroutine. Tasks commonly handled byMacro Service include output of a sequen-tial pattern to drive a stepper motor (withramping of speed) and movement of blocksof information like movement of a bufferof data via a serial port.

Within the K2 family are a number ofproduct lines. The five new productshave been added to the aPD7821X andaPD7823X lines.

The two new additions to the µPD7821Xline area ROM -less version (µPD78217A)offering 1K RAM and a mask ROM ver-sion (µPD78218A) with 32K ROM and 1KRAM. NEC plans to introduce anEPROM/OTP version (µPD78P218A)that features 32K EPROM in the first half

of 1992. All µPD7821X devices include thefollowing peripherals, most of which aresupported with Macro Service: 54 general purpose I/O lines Real-time output port (two four -bit orone eight -bit) A/D converter (eight -bit, eight -channel) UART for RS -232 interfaces Serial I/O port for micro -to -micro orperipheral communication One 16 -bit timer One eight -bit timer/event counter Two eight -bit timers Two timer -capture registers Six timer -compare registers One timer -capture or -compare register Four pulse -width modulated (PWM)outputs from the timers

Three remaining microcontrollers add -


Joseph Desposito

ed to NEC's µPD7823X line are a ROM -less version (µPD78237) with 1K RAM, amask ROM version (µPD78238) with 1KRAM and 32K ROM and an EPROM/OTP version (µPD78P238) with 1K RAMand 32K EPROM. All µPD7823X devicesinclude the following peripherals, most ofwhich are supported with Macro Service: 64 general purpose I/O lines Real-time output port (two four -bit orone eight -bit)

A/D Converter (eight -bit, eight -channel) D/A Converter (eight -bit, two -channel) One 16 -bit timer One eight -bit timer/event counter Two eight -bit timers Two timer -capture registers Six timer -compare registers One timer -capture or compare register Four PWM outputs from the timers Two modified 12 -bit PWM outputs

K2 devices can be used for motor con -

48 HOUR ELENCO & HITACHI PRODUCTS TO ORDERCALL TOLL FREE

SHIPPING AT DISCOUNT PRICES 1-800-292-7711

Hitachi RSO Series(Portable Real-time Digital Storage Oscilloscopes)VC 20MHz, 20MS/s

SPECIAL BUYHITACHI COMPACT SERIES SCOPES

Thts serer. provides many new functions such as CRTCollor Fro-6023 - $1 695

VC -6024 - 50MHz, 20AIS/s $1 995V-212 - 20MHz Scope $425 Readout. meesurernens (V10851065N6135A).

sanity Cir. (V1085). SweeplAne Autorweino. Delayed

VC -6025 - 50MHz, 20MS/s 82,195*wimp and Tripper Look bung Eelndl CIAT.You don1 feeltne compactness in term of performance and operation.

VC -6045 - 100MHz, 40MS/s $2.995 Hitachi Portable ScopesVC -6145 - 100MHz, 100MS/s $4 495 DC to 50MHz, 2 -Channel, DC offset func- V-660 - 60MHz, Dual Trace $1,149

RSO's Own few:hi Mature roe monk averaging, save Roe Alternate magnifier function V -665A - 60MHz, DT, w/cursor $1,345V-1060 - 100MHz, Dual Trace_ $1 395memory, smoothing. interpolation, pretrigoemak mow

aV525 CRT Rments. These scopes enable more- - eadout, Cursor Meas. $995

measure ccurate. V -1065A - 100MHz, DT, w/cursor $1,649smolt. -observation of complex wEntetionms, on adcitton to V-523 - Delayed Sweep $975 V-1085 - 100MHz, QT. w/cursor $1.995such fond.. as hardcopy via a plotter interlace and V-522 - Basic Model $875

V-11000 - 100MHz, Quad Trace 52,195waveform transfer via the RS -232C interface. Enpy the V-422 - 40MHz 5775comfortof analog and the power to owe V-223 - 20MHz delayed sweep $695

V-1150 - 150MHz, Quad Trace 52,695

25MHz Elenco Oscilloscope V-222 - 20MHz deluxe $625 Elenco 40MHz Dual TracetoGooMHz

$349 PRICE BREAKTHRU 'd 49550

S-1325 Dual Trace

1mV Sensitivity r CRT

............, 5,/ Operation

TV Sync

20MHz Digital Storage Oscilloscope Anownionw Scope. 2,, , , ,,,,,,,a ,,,,,,,,, DS2031014S/e remain; nee $79511 State -or -an recmcogy Octudes Proom

S-1340. High luminance 6' CRT

lmV Sensitrvrty' 10KV Acceleranon Voltage

17ns Rise Time X -Y Operatton

Includes 105 Probes (2) 15, 105 Probes included (2) lx,AA scopes include probes. schiernatim. operators manual and 3 year (2 yrs lor Benico scopes) world wide warranty on parts & labor. Many accessories availablelead Hitachiscopes. Call or write for complete specificapons on these and many other fine oscilloscopes. to, 100 Scope Probes: P-1 65MHz $19.95, P-2 100MHz 926.95

B + KTEST EQUIPMENTAll Models Available

Call for special price

Digital Capacitance Meter

lig CM -1550B

ii,4,2aaaausd

111--

$589,,...95..

.5% bask WI.Iwo eereBigrarewo,/Ctiee

Digital LCR Meter

1.1111

LC -1801

$.1.2.5,e,

ev.Coils 1:J011-.20011

......1411.4 Roe 'or .2°0

000t t

Btg 1- Display

Muliimele. 'dinCapacitance &Transistor Tester

.FI

FLUKEMULTIMETERS

FAF4li,,u:it:ecr°.7:1111_

FlukeCol tor special price

Soldering StationTemperature Controlled

e SL -30 $49arena Display-Temp Range

300..900,-Grounded Tip

Doormat Orotec

C2I A

Video Heed Tesler Four -Function Frequency CountersF-100 1201111

$179F-1, 12GH- . 7

$259Frequency. Perot Totalve,Sell Check vent Heri Slebilved Crystal OvenCiciltror, 8 dign LED Caper

jGMHz Oscilloscope1

CELLULARTELEPHONE

ACCESSORIES

Available for most ;HainesCall or write tel deans

HT -20B

..-- -.kw $55.95

-VHS

Y.'VHS head

. . 5-30001

$275.k

4. +

,ii ,_,.._. T g ed weeplnw,

Single C annelIdeal tor audio work

I a detectiveII-----7711Pate'dgLagor worn

A mat lorVCR work

Quad Power Supply XP -580

59.952.20V 0 2A

owe ,eret - 12VO IA

www5V 0 3A

w. - .5V (g.5A

Fully regulated and Mon &cue protected

Triple Power Supply XP -620Assembled $69

aiaw.. KR $45

I aa Fi.;2Io15Ve 1A.2M -151101A

(or 4 to 300 @ 1A)and 5V CS 3A

All the dasJi.ed Natures tor doing experimentsFeatures SW circuit protedicc. all supplies

AM/FM TransistorRadio Kit

with Training Course

Model ASVFIA 108

$26.9514 Transistors 5 Diodes

Makes a great school project

True MASA 1/2now Digit Ilultimeler

M-7000

't,' :; $135-, 05% DC PoSanaty

.1% Resistancewell Freq. Counterand Deluxe Case

GF-8016 Function Generatorwith Freq. Counter

$249Li.....__,J Sine. Square. Tnandie

Rao pRam 2 to 214,12Foot Counter .1 - 10AlisMt/Ed operabon

GF-80I 5 without Freq. MOW 5179

Function GeneratorBlox

XK-500 Digital / Analog TrainerA COMplela m/ni-lab for building, testing, prototyping analog and digital circuitsElences Digital/ Analog Trainer q specially designed for school potects. wile 5 bug -o parersupsim. Include. a function generator loth criminal* variade. sine, triangular, squat. wavebrew AI p.m supplies we regulated and protected against shorts.

1:1,,,.1.81V2 Sypply.. i .25 to 20VDC 0 .5 Ano(;',15.00215VDC:IAA7p)

(-1 25 to -15VDC 0 i Amp> $149.95 Assembledt. tIvac 0 1.mo

VDC 0 1 Amp Sti9.95 Klt .5VDC 0 i Am? 30000 Center upped 40 15VAC

9'nfieonoe Fur.l'Ori Generator Sine, Tr tanguler.

Square waveforV' 40. sr.

FJoe:mcyaltable In live rang.

' IASI. Frp=rolar DC offset Modulation FM -AM 91

?#?r ..5:1-;,.. 4. 4;':'EtZeo. TirOffir.,

,,,,,,,,, . ,.... la Clod, amplitude SVPP Karam way*

49600

$28.95ti p,r,...,,,e,

Press,. sin.. Mangle, squarewave barnlft lo I Wiz

AM or FM capability

Learn to Build and ProgramComputers with this KR

Includes. All Pans, Assembly and Lesson Manual

Model

5114-8000

$129.00

wpm.

Surtmq 501 Rm.' Y0004dtyr.P...M...' `-',.,_°'uecro_sq.sio, sent- weds you o www.,into.c,RAVe....FIC. and run a 8085 rni:r.oproomeor.......r.............................,.....................0.,e. PC -

Wide Band SignalGenerators

..

a orir . I 4,

SG -9000 $129RF Fry tOON-4501.111, AM Modula-

titan of 11010 Venable OF moo

15011/12 twin -in Counter $246

Breadboerde. Lorne,...aratc. agaimeecti consagn) ,

- l''' - - 'UPS Shipping: 48 States 5°.. & S S153 Min 510 Mox) Shipping 12 5 Rosewood, Deerfield, IL 60015IL Res 7 Too FAX 708 520 0085 (800)292-7711 (708)501-0710

ay oney ac uaran ee2 Year Warranty Prices &doyen To creep

WRITE FOR FREE CATALOG


trol, including stepper motors and servosystems. They're also suitable for such of-fice automation products as printers, plot-ters, typewriters and point -of -sale termin-als, including the disk drives and powersupplies they contain. They also find appli-cation in communications and transporta-tion equipment, like facsimile machines,telephone equipment, portable radios anddisplay controllers, as well as a wide varietyof general-purpose applications such assecurity systems, instrumentation, air con-ditioners, robotics and multi -mediaequipment.

As with all K2 products, the newest de-vices are offered in a variety of packageconfigurations, including 64-, 80-, 84- and94 -pin packages. Prices in 1,000 -piecequantity are: µPD78217A, $7; µPD78218A,$8.50; µPD78237, $8.25; µPD78238, $10;µPD78P238, $18 (OTP)/$65 (EPROM).

NEC offers an evaluation board and de-velopment system for support of each fam-ily. The real-time in -circuit emulator sys-tem, IE-78240-R, with one probe is offeredat $9,490 to support the RD7821XA group,and the IE-78230-R support the µPD7823Xmembers. Evaluation boards EB-78240-PC and EB-78230-PC are priced at $595each and support, respectively, theµPD7821XA and µPD7823X families.They can be used alone or with the sameoptional probes to form a low -end in -cir-cuit emulation system.

Two -Serial -Port ChipMaxim Integrated Products' (120 SanGabriel Dr., Sunnyvale, CA 94086)MAX249 is one of seven new devices fromits RS -232 line of + 5 -volt multi -channeldrivers and receivers. The MAX249 trans-ceiver offers six RS -232 drivers and 10RS -232 receivers-two complete DataTerminal Equipment (DTE) serial ports inone IC (see Fig. 1).

An important feature of the MAX249is its separate shutdown mode for eachport. In shutdown mode, power supplycurrent is reduced to 8 µA (typical), and theMAX249's receivers are still able to receivedata at up to 20 bits/sec. The new deviceuses space -saving 1-µF capacitors, makingit well -suited for RS -232 applicationswhere space is limited, such as in laptopPCs. The chip meets all EIA-232D andEIA/TIA-562 specifications and is guar-anteed to operate at data rates up to 64Kbits/per second.

MAX245, MAX246 and MAX247 re-quire no external components and are idealfor RS -232 limited -space applications.MAX244, MAX248, and MAX249 use1-µF capacitors.

Prices for 1,000 -piece quantity are:MAX244, $7.65; MAX245, $12.15;MAX246, $12.15; MAX247, $12.15;MAX248, $7.65; MAX249, $7.65.


Cross -Assemblers from $50.00

Simulators from $100.00

Cross-Disassemblers from $100.00

Developer Packagesfrom $206.00(a $50.00 Saving-§)

Make Programming EasyOur Macro Cross -assemblers are easy to use. With powerfulconditional assembly and unlimited include files.

Get It Debugged --FASTDon't wait until the hardware is finished. Debug your softwarewith our Simulators.

Recover Lost Source!Our line of disassemblers can help you re-create the originalassembly language source.

Thousands Of Satisfied CustomersWorldwide

PseudoCorp has been providing quality solutions formicroprocessor problems since 1985.

ProcessorsIntel 8048 RCA 180205 Intel 8051 Intel 8096,196kcMotorola 6800 Motorola 6801 Motorola 68HC11 Motorola 6805Hitachi 6301 Motorola 6809 MOS Tech 6502 WDC 65CO2Rockwell 65CO2 Intel 808085 Zlog Z80 NSC 800Hitachi HD64180 Mot. 68k,8,10 Zlog Z8 Zlog Super 8

All products require an IBM PC or compatible.For Information Or To Order Call:

PseudoCorp716 Thimble Shoals Blvd, Suite E

Newport News, VA 23606(804) 873-1947 FAX:(804)873-2154


Dual VGA DriversColographic Communica-tions has new drivers for thecompany's Dual VGA graph-ic cards and Windows thatpermit a single large windowto be displayed across twoscreens. Or two full-size win-dows can be opened at thesame time. More viewablewindows and the ability topick them up and move themover two physical screenboundaries in real time givesthe user greater flexibility.With the new driver, Win-dows can address up to eightdisplays simultaneously (re-quires additional Dual VGA

Draw Your Own PlanFor Home, Work, or Sch ool

$39.95LaserCAD,, APPRENTICE

30 DayGuarantee

Architectural Mechanical Electrical Structural Civil Misc

90% of all drawing is done with only one menu Comes with automatic dimensioning modes

Includes a library of over 122 symbols Can draw at any scale or angle Create/modify symbols easily Is a true vector -based CAD program

Comes with over 38 fill/hatch patterns Has (DXF) to exchange drawings

Zoom or pan to any size or angle Earn extra money drawing, on the side Easy to use yet has high functionality

Order Now and receive a $395 set ofhouse plans on disk ABSOLUTELY FREE

Sayet Corp PO Box 672 Orem, UT 84059 (801) 225-2780

What's New!

I as...

eihri

graphic cards). $795 and up.Colographic Communica-tions Corp., 5388 New Peach-tree Rd., P.O. Box 80448, At-lanta, GA 30366; tel.: 404-455-3921: Fax: 404-458-0616.



Fax ProtectorIsofax from Tripp Lite pro-tects fax machines fromspikes on both ac power and

telephone lines. The Isofaxcombination surge suppresserfeatures two ac outlets withIsobar -quality surge suppres-sion and two surge -protectedRJ-45 phone -line jacks forcomplete protection of faxmachines and/or modems.Isofax plugs directly into astandard ac outlet. It's UL1449 listed for 330 -volt let -through. A green LED indi-cates the circuitry is function-ing properly. $65. Tripp Lite,500 N. Orleans, Chicago, IL60610-4188; tel.: 312-329-1777; Fax: 312-644-6505.


Virtual Panel MeterTexmate introduces a hard-ware/software package calledVPM1, which combines thesimplicity of a panel meter withthe flexibility of a personalcomputer. The VPM I is a 16 -bit A/D converter (60,000counts) with optically -isolated

inputs of 20 mV/200 mV/2volts/20 volts dc. Input con-nections are made via standardbanana plugs at the rear of thecomputer. All configuration isdone in software, from a menuthat requires only a keyboardor mouse. The software sup -


ports four input cards, one be-ing required for each signal.Optional data logger and largedisplay software are available,as is a demo disk. $545. Tex -mate, 995 Park Center Dr.,Vista, CA 92083-8397; tel.: 619-598-9899; Fax: 619-598-9828.


What's New!

Parallel -Port ASICTrantor Systems offers a cus-tom ASIC peripheral control-ler chip for parallel -port add-on products. Called the P3C,the new general-purpose chip isgeared towards products in-tended to plug into IBM/com-patible parallel ports. The P3Cdramatically simplifies the taskof designing parallel port add-ons and addresses three prob-lems in parallel port add-on de-sign: unidirectional versus bi-directional ports, concurrentuse of a printer and I/O speed.

Products that use the P3Ccan take advantage of thegreater speed of bidirectionalports while maintaining com-patibility with the more com-mon unidirectional ones. TheP3C is available in samplingquantities in a 60 PQFP pack-age. Trantor Systems, Ltd.,5415 Randall P1., Fremont,CA 94538-3151; tel.: 510-770-1400; fax: 510-770-9910.


Micro Channel MemoryBoca Research has a new 8Mzero -wait -state RAM memoryboard for IBM PS/2 MicroChannel Architecture sys-tems. The board provides ex-tended memory support forDOS, UNIX and XENIX. Itcarries its own Micro ChannelID, making it automaticallyrecognized by the system atcold boot, and is easily con-

figured through the IBMPS/2 installation programand a configuration file sup-plied. Boca supplies EMS 4.0

software drivers for applica-tions that require expandedmemory. The board is offeredin four configurations (OK,2M, 4M and 8M), and uses 1Mx 9 SIMMS. $195 (OK). BocaResearch Inc., 6413 CongressAve., Boca Raton, FL 33487;tel.: 407-997-6227; Fax: 407-997-0918.


Smart CardsThe Micro Card QwikLINKmodel TLP0720 is a high-performance, second -genera-tion smart card "drive." It of-fers high-speed card commun-ication design, LexanTM case,small footprint and single -ca-ble design. Micro Card offerstwo families of card productsfor use with the TLP0720, theSCOT single -service operatingsystem and the TB multiple -service. Capacities range from8K bits to 64K bits.

Security within a TB inte-grated -circuit card is based onencryption techniques. Pri-mary security functions in-clude random number genera-tion, password authentica-tion, secure write, cipheringand deciphering, message -authentication code genera-tion and verification and se-cure erase. The TB card oper-ating system utilizes an algo-rithm that conforms to DESTLP0720. $225. Micro Card

ORGANIZE AND PROTECT YOUR

COPIES OF COMpUtetQaftCustom-made titled cases and binders, designed tohold a year's issues, provide the storage systemto help protect your valuable copies fromdamage. Reinforced board coveredwith durable leather -like materialin (color), title hot -stamped in(gold/silver), cases V -notchedfor easy access, binders havespecial spring mechanism tohold individual rods which easilysnap in.

Cases: 1-S 7.953-521.956-539.95

Binders: 1-5 9.953-527.956-552.95

CASE

BINDER

ComputerCraftJesse Jones Industries, Dept. Mod.E499 East Erie Avenue, Philadelphia, PA 19134

Please send cases,

CI Enclosed is $

Charge my: (Minimum $15)0 American Express Visari MasterCard F. Diners Club

bindersAdd SI per case/binder postageand handling. Outside USA52.50 per case/binder. (U.S.Funds only.)

Card # Exp. Date

Signature

Charge Orders: Call TOLL FREE 7 days, 24 hours 14004254690

Print Name

AddressNo P 0 Be. Numbers Please

City/State/7p

PA Residents add 7% sales tax

L SATISFACTION GUARANTEED

Technologies, Inc., 15851 N.Dallas Pkwy., Ste. 500, Dallas,TX 75248; tel.: 214-788-4055.


HIGH TECHNOLOGYKITS & MATERIALS

MC68HC705C8 DEVELOPMENT SYSTEMS $ 89.95PC BUS 'CYANCE' CHASSIS/EXPANDERS $ 99.95DIGITAL BENCH POWER SUPPLIES 69.95SERIAL/PARALLEL PROTOCOL CONVERTERS $ 74.95PARALLEL PRINTER PORT SWITCHES 69.95NEURAL NETWORK ARRAY MODULES call for specificsROBOTS & ROBOTIC COMPONENTS call for specificsPORTABLE LASERS & OPTICAL EQUIPMENT 99.95PROGRAMMABLE PARAMETER BATTERY CHARGERS $ 89.95PC ELECTRICAL STORM & PHONE MONITORS 99.95TALKING DIGITAL LOGIC PROBES S 69.95DIGITAL SIGNAL PROCESSOR MODULES call for specificsSEMI -CUSTOM ALUMINUM PROJECT CASES call for specificsDIGITAL VOICE AND TAPE SCRAMBLERS 39.95

AUTOMATIC PHONE RECORDERS/MONITORS 39.95

"SHOTGUN" SURVEILLANCE MICS/SCOPES $ 49.95DIGITAL PSY-OPS "LEFT -FIELD" GENERATORS $ 99.95MICRO "FOXHUNT & BUMPER" TRANSMITTERS S 49.95SURFACE -MOUNT 140-160MHz XMTR/RCVR KITS $ 49.95DIRECTIONAL 140-160MHz LOCATOR/RECEIVERS $ 69.95

BRIEFCASE LISTENING/RECEIVING DEVICES $ 99.95DIGITAL MCT(tm) MIND CONTROLLERS S 99.95CYBER PROBES (DYNAMIC FIELD/PSI DETECTORS) $ 39.95DIGITALLY TUNABLE RADIO FILTERS $ 59.95SYNTHESIZED 2M & 70CM XMTR/RCVRS $ 99.95

CALL NOW TO ORDER! (catalogs available upon request)

(501) 839-8293U.S. CYBERLAB, INC.

Rt 2 Bx 284 Cyber Rd., West Fork, AR 72774




Computer Games By SF Sparrow

If you have a good thing, make it better.This axiom may not be official policy atsoftware companies, but using it on goodsoftware makes good sense. The objectiveis to stay in head -to -head competition withother companies. Combine this with theunpredictable nature of the computergame market, and you have a healthy tech-nological sparring that, in its own way,might be called a war. I like to call it TheUpgrade Wars.

The Wars BeginOnce upon a time, personal computers thatperformed real work were priced out of

Scouring the sands of tie Middle East.

The F-16 takes off after a long hiatus.

The Upgrade Wars

reach for most people. Commodore wasking of the computer hill because it gavegood computing at a likewise price. ItsModels C-64 and C-128 are still found inhomes today, some of them even in use.

A software company named Micro-P-ose fired up the Commodore 64 withmilitary simulations. One of these, StealthFighter, was an early strike and quicklyestablished MicroProse as a high-poweredleader in the Upgrade Wars.

Stealth TechnologyStealth Fighter for the Commodore por-trayed the then highly secretive aircraft.

Although the Commodore version wasloads of fun, it was limited in scope. Ar-mament selection was sparse, and flyingat altitudes of thousands of feet was notonly done with impunity but expected. Thegame lacked much in the way of stealth tac-tics. But when one owns only a C-64, onetakes what one can get and enjoys it.

Stealth Fighter, a rousing bang-up jobfor MicroProse, used virtually all the re-sources of the vintage C-64. As computergarners soared to gaming heights andplayed the invisible nemesis to radar, Mi-croProse was strategically planning toescalate the War.

Accordingly, the Commodore Stealth

The Falcon's complex new look.

The Apache helicopter sits ready, willing and able.

Say You Saw It In Com.puterCraft May 1992 / COMPUTERCRAFT / 85

Fighter was reincarnated in the form ofF-19 Stealth Fighter. The new incarnationsported smoother operation, more realisticsimulation and graphics so much improvedthat they served as a nucleus around whichfuture MicroProse games would build.This new IBM version of Stealth Fightertook off with fire and smoke like a reborndigital Phoenix.

ReincarnationF-19 was the unequaled simulation for theStealth Fighter. It stayed that way for along time, as measured by computer gamereckoning. F-19 lets players fly 99 missionsbefore forcing retirement of a playingcharacter. By then, any air -combat enthus-iast worth his joystick had learned Stealthoperation and tactics and had set skill levelsat Veteran and Elite. Stealth technology,still riding the stratosphere of the best, ap-proached the end of its service life andneeded a boost.

Ironically, while the real Stealth Fighterspeared through the cover of night in hid-den flight testing and secret missions, Mi-croProse worked ambitiously on an up-grade to F-19. Surprisingly to industry ex-perts, the Pentagon performed outstand-ingly on keeping security clamps on the realStealth. But when MicroProse finally gota look at it, an upgrade to F-19 wasn't farbehind. The upgrade rolled out as F -117A

Nighthawk and ascended with a new look,better graphics and yet more realistic sim-ulation. Nighthawk is simply the best andmost definitive simulation of America'sradar -illusive fighter.

F -117A is up-to-date and complete withmissions into the Persian Gulf. It has bril-liant graphics and tests players with in-triguing mental challenge. Actually, thenecessary tactics of proper ordnance us-

age, mission planning and alert flying arethe game's focus. The whiz-bang visualsof game technology just make the brain-work more enjoyable.

An interesting feature comes with Night-hawk: the option of flying the Lockheedversion of the Stealth Fighter or wingingoff in MicroProse's own version. The dif-ference is that the Lockheed version ismore like a real -life mission. With it, youhave only two weapons bays, you can'tcarry air -to- air weapons and there's nocannon for dogfighting. You always fly atnight and never launch from a carrier. TheMicroProse version isn't quite as stealthyas the Lockheed version, but it affordsmore variety in weapons and types of mis-sions you can fly. And when the going getstough, you can take out the oppositionwith air-to-air missiles.

Rotary -Wing AttackOne of the meaner combat helicopters everto hit the field is the AH64-A, otherwiseknown as the Apache. Some consider it tobe the meanest. Well, the experts can de-bate the matter in real life. Slide into theworld of computer games, and Gunship isundoubtedly the best helicopter combatsimulator for the personal computer.

Like MicroProse's Stealth Fighter,Gunship had its genesis in the Commodoreera. Owners of the then high-tech IBM PCXT and faster clones had to watch in aweand envy as skilled Commodore helicopterpilots swooped upon enemy infantry,tanks and radar sites with free -fire rocketsand laser -guided missiles. Sometimes theenvy bordered on pain.

Fortunately for simulation enthusiasts,MicroProse "brass" was planning the tac-tical insertion of an IBM version of Gun-ship. Not only would it offer a more -fertile

UniversalEmulator

Assembler

Over 170 different microprocessors are supportedin this high-performance software/hardwareenvironment for assembly language development.Call today for a FREE ECAL Demo Disk.

For more infomation

Vail Silicon (305) 978-6083

NOW - THE ALL NEW URDA®, INC.

SDK'386TM*386 is a trademark of Intel Corporation. Used by permission.

32 err MICROPROCESSOR TRAINERAND DEVELOPMENT SYSTEM

With optional 80387 Floating Point Cioprocessor, 16 Kbytes of EPROM 'orMonitor. Utilities and User Expansion, 32 Kbytes of Static RAM, 508

Matrix Keypad, 40 Character x 2 Line Dot Matrix Liquid Crystal Displaywith Optional Accesssories.

Also available:

the 8 Bit SDK -85 and the 16 Bit SDK -86

Coming in 1992:

the 8 Bit SDK -51 Microcontroller

CALL URDA®, INC.1-800-338-0517 or (412) 683-8732

URDA®, Inc. Has Additional Single Board Products:

8086 68000 68020 68030 32010 DS P

With Cross Assemblers for MS-DOS Computers

development platform for Gunship design-ers, but an opportunity for markedchanges in games design as well. It seemsthat, without hesitation, Gunship design-ers snatched the opportunity and ran withit like a super -spy carrying high-level in-formation.

The new Gunship was everything thatIBM'ers wanted and more. Graphics weremuch better, combat scenarios widenedand got more realistic, helicopter flightcontrols became more reactive and overallgame play jumped in intensity. Deliberate-ly, the national computer game combatarea had a new player. Commodore fanswatched in envy as the Upgrade Warsbranched toward a new evolution.

Years passed. Gunship successfully de-nied all challenges to its rotary -wing air su-periority. Then, after pleadings from hun-gry garners, Gunship re-emerged with anew look and graphics quality that leapedan order of magnitude. Christened Gun-ship 2000by its designers, the new conceptgave users a choice of five aircraft, includ-ing the Kiowa scout ship, Blackhawk as-sault/transport, the trusty Cobra and theol' Apache of yesteryear. Gunship 2000 of-fers more kinds of weapons, updated com-bat scenarios that include the Persian Gulfand the long-awaited chance to fly yourchopper in groups. It's a welcome upgradefor a game that remains in a class by itself.

CompetitionIt's true that MicroProse established itselfearly in the game of combat simulations.But other warriors suited up for computercompetition.

Spectrum HoloByte pushed into mili-tary simulations with Falcon, its renditionof the venerable F-16. At first launch,Falcon came in four-color CGA, whichwas a tad below EGA standard, but toler-able nevertheless. Falcon was an early at-tempt at serious flight simulation for theF-16. It had a few programming quirks anddocumentation problems, but PC gamerseagerly bought it and flew their IBM XTsinto the blazing sky of imagination.

A succeeding version of Falcon flew asa chaser behind the original. Falcon ATwas its moniker and it effectively raised thesimulation to EGA graphics, better play -ability and faster execution of the 80286processor. Falcon A Twas difficult to play,nearly impossible to land and had a usersmanual that read like a technical docu-ment. But it was fun enough and remainedthe best F-16 simulator.

Computer games have a relatively shortmarket life. No one knows this better thanthe people who design them. Therefore, itwas puzzling to simulation enthusiastswhen, after a normal period of time, nofurther Falcon upgrade was seen. An eter-





nity of about two (maybe three) years wentby. Still no new Falcon. Finally, like a callfrom the presidential hot line, Falcon 3.0was announced. The message set the com-puter game world buzzing with anticipa-tion-simulations couldn't wait. Well, an-other year went by, and then some moremonths with no new Falcon making its ap-pearance. What was wrong?

Spectrum HoloByte explained the longwait in the pages of the Fall/Winter 1992edition of its newsletter, The SpectrumHologram. Spectrum HoloByte CEO Gil-man Louie said, "Falcon 3.0 is probablythe most ambitious flight simulation everdeveloped. Few sims can boast the samededication to detail and accuracy. Spec-trum HoloByte is uncompromising whenit comes to quality-we simply will not re-lease a product until it's ready." The news-letter went on to reasonable explanationsabout technical delays. Computer garnerswere willing to forgive the wait, but howmuch longer would it take?

Suddenly, appearing with the shockingimmediacy of a Stealth fighter, Falcon 3.0landed on the shelves of computer stores.Some resellers quickly sold all copies. Gil-man Louie had been right. The game iscomplex, more so that any of its predeces-sors. But even after years of waiting, theinitial release wasn't ready.

lems with this Falcon from the start. Mypersonal copy refused to install. The prob-lem was quickly remedied by downloadinga fix from a bulletin board. Subsequent-ly, I experienced computer hangs, wherethe game froze in the middle of play, oc-casions when keyboard commands weren'tobeyed and much trouble with the throt-tle controls. Communication with otherusers verified these game quirks as com-mon experiences.

Already, weeks after it release, a Falcon3.0 update (Version 3.0a) is sitting on abulletin board. A text file comes with it thatoutlines the numerous bug fixes being ad-dressed. Despite Spectrum HoloByte'sstatement that it wouldn't release a gamebefore it's time, Falcon 3.0 was clearly notready to be properly released.

With game quirks, fixes and updates,Falcon 3.0 is still the best F-16 simulator.The game manual still reads mostly like atechnical document and could be better or-ganized. The game itself is still difficult tomanage while playing, but once you put inthe hours of study and practice, some ofthe bugs and quirks can be ignored bystaunch simulationists. More generic play-ers might wait until the bugs are shaken outbefore signing on.

Global ConflictThe beginnings of the Upgrade Wars saw

MicroProse take an early lead. SpectrumHoloByte competes very well, although itisn't as prolific. Other game designers havesince entered the fray, to the delight ofcomputer users.

Deserving of honorable mention are:Electronic Arts for the intriguing Attack

Sub and the scholarly Chuck Yeager seriesand for the gimmickry of Megafortressand the headiness of Harpoon, which hasa new Persian Gulf Battleset.

Maxis for two versions of the action -or-iented Jet Fighter the Adventure.

LucasFilm Games for spectacular his-torical simulations like Battlehawks, Bat-tle of Britain and Secret Weapons of theLuftwaffe, which has a new Tour of Dutyaddition for the P-38 Lightning and theP-80 Shooting Star.

Spectrum HoloByte for the tough actionof Tank and a good effort at Falcon 3.0.

MicroProse for many quality simula-tions, including two versions of Silent Ser-vice, two versions of the hot action of F-15Strike Eagle, the brawling M1 -Tank Pla-toon and a superbly playable rendering ofTom Clancy's Red Storm Rising.

The future of the Upgrade Wars lookspromising, as more players and new tech-nology join the fight. When this particularwar heats up, its good for game designers,good for game players and good for a

war we candeal with!

Bird's Eye View

F -117A Stealth Fighter 2.0, $69.95MicroProse180 Lakefront Dr.Hunt Valley, MD 21030Tel.: 301-771-1151

Requirements

RAM MemoryGraphicsSoundControllers

640KVGA onlyIBM, AdLib, RolandJoystick, Mouse

Evaluation

Documentation GoodGraphics ExcellentLearning Curve LongComplexity HighPlay Length MediumPlayability GoodIn brief: A fitting upgrade to a favoriteand long-standing simulation. Recom-mend an 80386 and joystick for bestperformance.


Bird's Eye View

Gunship 2000, $69.95MicroProse180 Lakefront Dr.Hunt Valley, MD 21030Tel.: 301-771-1151

Requirements

RAMGraphicsSound

640KVGA onlyIBM, Tandy, AdLib,Roland

Controllers Joystick

Evaluation

Documentation GoodGraphics ExcellentLearning Curve LongComplexity HighPlay Length MediumPlayability GoodIn brief: Improvements on the best heli-copter combat simulator. Recommendan 80386 and joystick for best perfor-mance.


Bird's Eye View

Falcon 3.0, $79.95Spectrum HoloByte2061 Challenger Dr.Alameda, CA 94501Tel.: 510-522-3584

Requirements

RAM Memory 1M, DOS 5.0Graphics VGA onlySound AdLib, Roland,

SoundBlasterControllers Joystick, Mouse

Evaluation

Documentation FairGraphics ExcellentLearning Curve LongComplexity HighPlay Length MediumPlayability FairIn brief: Long-awaited upgrade. Quirkyand sometimes vexing, but worth a shot.Recommend an 80386, joystick and ex-panded memory for best performance.Math coprocessor needed for high-fidel-ity flight model.



CornputerCraft MartREMOVE

HARDWARE LOCKS

PROTECT YOUR INVESTMENT!MAINTAIN PRODUCTIVITY!

Software utility that allows forthe removal of hardware locks.

Avaiable for most majorCAD/CAM and PCB

software programs

Easy - Simple - Guaranteed

Programs start at $99.00 U.S.Visa and Mastercard Welcome

Call or Fax for mom Information

SafeSoft Systems Inc.202-1100 Concordia Ave.Winnipeg, Mb. R2K 4B8Canada

Phone (204) 669-4639FAX (204) 6613-3566

CIRCLE NO. 87 ON FREE INFORMATION CA RI)

Satellite -TVSAVE 40% - 60%

48 Page Catalog, it's loaded witAll Mato( Brands. Systems,Upgrades. Components & AccessoriesHuge Savings. Easy Installation andComplete Intruchons 800-334-6455SKYVISION INC. 218.739-5231 IntlISIS FRONTIER DRIVEFERGUS FALLS. MN 56537

MOW

FqF

INSTALL OR UPDATE YOURSELF!

Order Back Issues of

Compute,Craft

ProtoQuick Z8 and 8051

Run ledhdelae aradkalrons w expenmenlal hardwarecorn ne senal pan WMliOUT PROGRAMMING,

Lev 27. /ere r er .erwas dp p 320 EPPCA4 02 im RAM

12 op nMM. 0,00n 0.0 onm FiSdari C gene pen w Da2S cone M. Sys sn EPROM ow source cob AsomOded mods to ton Or only MS SOS cross -assembler ondodo0

ProdoOuick Z8 and 8051

$99.00 ....Sod areSc e

'SO rieuxibellern Pealnom OH USA

(513) 561-2060

CABLE TV DESCRAMBLERS*CONVERTERS*

and ACCESSORIES.

SAVE MONEY.DON'T RENT!

PANASONIC, JERROLD, OAK,PIONEER, SCIENTIFIC ATLANTA

AND MORE LOWEST PRICES. FREE CATALOG.

CABLE READY (800) 234-1006COMPANY

Classified Commercial Rates: $1 per word, 15 -word minimum ($15.00) prepaid. (Wordcount includes name and address; ZIP code and abbreviation each count as one word;P.O. Box number and telephone number count as two words each.) Indicate free cate-gory heading (Computers, Software, Electronics, Video or Miscellaneous). A specialheading is available for a $6 surcharge. First word only is set boldface caps at nocharge.

Add 25C for each additional boldface word.Non -Commercial Rates: FREE to subscribers, as space permits; maximum 15 words. Arecent COMPUTERCRAFT mailing label must accompany ad.(All advertisers with P.O. Box addresses must supply permanent address and telephone

number. Copy is subject to publisher approval.)Mailing Information: Copy must be received by the publisher by the 25th of the thirdmonth preceding the cover date. Send Advertising material with check or money order orcredit card information (Visa or MasterCard only) with number and expiration date to:COMPUTERCRAFT, Classified Department, 76 N. Broadway, Hicksville, NY 11801.

COMPUTERS

80C52 -BASIC microcontroller board. BASICinterpreter, 32K RAM, 16K EPROM,EPROM programmer, RS232, expansion con-nector. Bare board with manual, schematics$19.95 + $3 P&H. 80C52 -BASIC micropro-cessor chip $24.95 + $1 P&H. Assembled andtested $119.95 + $5 P&H. MD residents in-clude sales tax. SASE for info. Prologic De-signs, P.O. Box 19026, Baltimore, MD 21204.

IBM PC AND LAPTOPS VIDEO DIGITIZ-ER, 640 BY 480 RESOLUTION. 256 GRAYLEVELS $89.98. DEMO DISK $3, INFOR-MATION $1. COLORBURST, BOX 3091NASHUA, NH 03061. PHONE (603) 891-1588.

ELECTRONIC Circuit and ConstructionProject References. PC/MSDOS softwaredatabase, 1500 circuit and project citationscompiled from 5 electronics magazines, 27years publication. Search by subject or key-word, both disks included, HD required.$19.95. JRH & Associates, 4255 S. BuckleyRd. 181, Aurora, CO 80013. (303) 699-5835.

COMPUTERS AND ACCESSORIES!Mouse $9.00, Keyboards $18.00, Buy DirectFrom Foreign Manufacturers! Any Quantity!EXCELLENT BUSINESS OPPORTUNI-TY! Complete and ALL details $12.00 Post-paid. Free additional information. SMI, Box5500-R, Lakeland, FL 33807.

TEMPERATURE -SENSOR, lm cable. Fitsany 8052BASIC board. Software, assembledPCB, $18.00. LOGTROLLER, Data loggerand controller. Plans, $12.00. 8748, 68705,BAREBOARDS, $9.00. TENSOR, Box2543-C, Thunder Bay, Ontario, P7B 5G1.

NEVER anything like it before! THE LIT-TLE BLACK BOOK OF COMPUTER VI-RUSES teaches you how to create living vi-ruses, with working examples and completesource code. 196 pages. $14.95 ppd. AmericanEagle Publications, Box 41401-R, Tucson, AZ85717.

ELECTRONICS SOFTWARE. From $2. perdisk. IBM 5.25". Free catalog on disk. Stack -house, Box 502, Dayton, OH 45401-0502.

MEASUREMENT -Microprocessor plans.Free catalog. Temperature Datalogger plans,$5.00. TENSOR, Box 2543-C, Thunder Bay,Ontario, P7B 5G1.

COM PUFACTS The professional's computertroubleshooting manual. Nothing like it onthe market today. "Tricks of the Trade" fromworking technicians. Thoroughly illustrated.Electronic students MUST read this beforejob hunting. BBS access included. 30 dayguarantee. $39.95 Computers Etcetera, POBox 8090, Berkeley, CA 94707-9991. 510-841-5201.

68HC11 SINGLE -BOARD COMPUTER-MAG-11c described in series of Computer -Craft articles starting in January, 1992. Semi -Kit $69; includes bare board, all necessaryIC's, IC sockets, construction manual, PCsoftware and other documentation. Alsoavailable separately: Bare double -sided pcboard -$25; includes component guide andparts list, MC68HC11A1P-$25.00, PC disk-$10.00 (specify 5" or 3") All prices post-paid. MAGICLAND, 4380 S. Gordon, Fre-mont, MI 49412.

CLUBS

P.C. MODEM CLUB Correspond with Crea-tive Modem users, LINK/UP with ENTHUS-IAST Nationwide, FREE Membership, Send$1 for application & postage to LINK/UP,P.O. Box 4534, Waterbury, CT 06704. Also,List FAX and 1-900 numbers.

SOFTWARE

FREE IBM PD and Shareware disk catalog.Low prices since 1988! ASP Approved Ven-dor. Finto Software, Dept CC, Route 2 Box44, Rosebud, TX 76570.

IBM Shareware, latest versions of games,graphics, education, windows, adult, utilities,more . . . write for list. Major Electronics,2930 Sepulveda Ave., San Bernardino, CA92404.


RUN RC SERVOS NO CARDS NEEDED!

Mouse controls 8 RC Servos from a Parallel Port

ELECTRONICS

SURVEILLANCE - COUNTERSURVEIL-LANCE. Guaranteed lowest prices! Unbeliev-able, Detectors, Jammers, Transmitters, PhoneSecurity, Cameras, Personal Protection, Books,More! Huge catalog $5.00 (Refundable) PRO-TECTOR P.O. Box 520294-B, Salt Lake City,UT 84152.

VIDEOCIPHER II/Satellite/Scanner/Cable/Amateur/Cellular/Repair Manuals, Modifica-tion Books & Software. Catalog - $3.00. TEL-ECODE P.O. Box 6426 -CC, YUMA, AZ85366-6426.

KENWOOD & ICOM Service Bulletins. 175 +pages covering all models. $39.95 Catalog -$3.00. CODs 602-782-2316/ FAX 602-343-2141. TELECODE Box 6426 -CC, Yuma,AZ 85366-6426.

UNITED STATES Frequency Allocations: Ra-dio Spectrum, 32 by 50 color chart shows radio,tv, mobile, amateur, etc. zones. $7 postpaid.PUBNETIX, Box 1022, Laurel, MD20725-1022.

CABLE TEST CHIPS. Scientific-Atlanta8550-321, 8500-310, 311, 320, 321 (specify) -$33.95. 8580-338 - $69.95, 8570/8590 - $79.95.ZENITH ZF- I - $33.95. STARCOM 6 - $33.95.STARCOM 7 - $49.95. TOCOM 5503/07 VIP- $33.95. TELECODE P.O. BOX 6426 -CC,YUMA, AZ 85366-6426.

PHONE or room bugged? Detailed instructionsmanual shows how to check your phone with anOHM meter for wire taps. Also included how tocheck rooms for bugs. Manual $7.95. Plans forphone protection device $5.00. Also -catalognightvision scopes and surveillance & counter -surveillance devices catalog $3.00. Send moneyorder to Angelos Electronics, PO Box 1871,Loomis, CA 95650.

COMMUNICATION AT ITS BEST.AR-1000XC $399, AR -2500 $469, AR -3000$969, ATS803A $195. We sell a variety of CB's,Scanners, Radar Detectors, Caller ID's andmore. Visa/MC/Diners. FREE SHIPPING!Turbo Electronics, PO Box 8034, Hicksville,NY 11802. Inquires: (516) 938-1946. Orders:1 -800 -33 -TURBO.

NEW! Pocket -sized electronic compass instant-ly and accurately shows direction on its digitaldisplay. At only $59.95 & $2.50 shipping andhandling, get this high-tech version of this an-cient tool today! Entek, P.O. Box 72132. Albu-querque, NM 87195.

VIDEO

VHS -VCR Repair Solutions Sets I, II, III, IV,V, VI. Each contains 150 symptoms and cures,updated cross reference chart, free assistance,$11.95 each all six $59.95. Eagle ElectronicsBox A, 52053 Locks Lane, Granger, IN 46530.

TV NOTCH FILTERS PHONE RECORD-ING EQUIPMENT, BROCHURE $1.00. MI-CRO THinc. BOX 63/6025, MARGATE, FL33063. 1-305-752-9202.

CABLE T.V. DESCRAMBLERS, Convert-ers, Guaranteed, LOWEST PRICES, AllBrands Available, CNC Concepts Inc., P.O.Box 34503, Minneapolis, MN 55434.1-800-535-1843.

CABLE

ACTIVATE your Jerrold, Tocom, or ZenithBox (Fully) in just minutes. Test chips only$50.00. No CA. Sales. Orders Call 1-800-452-7090. Information 310-867-0081.

JERROLD Test chips for Starcom 6 and 7. In-stalls in just minutes only $50.00. No CA.Sales. Orders 1-800-452-7090. Information310-867-0081.

CABLE TV EQUIPMENT

CABLE TV converters and descramblers dis-count center. Jerrold, Tocom, Hamlin, Scien-tific, Atlanta, Oak, Zenith. Order your today800-962-6836.

MISCELLANEOUS

MORSE Code? No Problem. You can in-crease your speed, no matter how many timesyou've failed before. Results guaranteed whenyou follow the instructions. PASS Publish-ing's CW Mental -Block Buster program helpsyou explode mental blocks that hold you back.Based on 40 years of research, the CW Mental -Block Buster uses guided meditation, dynamicvisualizations, and powerful affirmations toblast through mental blocks. You can docode! That means new bands, more contacts,more fun! (This is not a CW practice tape.)The CW Mental -Block Buster audio cassetteand practice booklet are only $24.95 ppd. inthe US (NY residents add $2.00 sales tax). In-fo: 516-584-8164. PASS Publishing, P.O. Box570, Stony Brook, NY 11780.

ASIAN LADIES want correspondence forfriendship, marriage. SUNSHINE INTER-NATIONAL -Dept. TW, Box 5500, Kailua-Kona, Hawaii 96745. (808) 325-7707.

ATTRACTIVE ORIENTAL LADIES seek-ing correspondence, marriage. Professionalintroductions since 1984. Asian Experience,Box 1214TZ, Novato, CA 94948. (415) 897-2742.

COMPUTER PRODUCTS AND ELEC-TRONICS EQUIPMENT. Home and busi-ness. Catalog $3. (Refundable) B&R Enter-prise, P.O. Box 662, Portage, MI 49081.

THAILAND Women, marriageable, Tours,Correspondence: 300 Photograph Brochure$3 Club Thai, Box 974(m) Miami, FL 33233.

IDEAS WANTED

INVENTORS! Can you patent and profitfrom your idea? Call AMERICAN INVEN-TORS CORP. for free information. Servinginventors since 1975. 1-800-338-5656.

RoboticsGamesLet your PC manipulate the world! Get Radio Control Servosat most any hobby store and wire them to your AT computer sParallel Port.

SERVO 1 -Jr. $49.95Your 2 or 3 button mouse controls 8 Radio Control Servosindividually or as four XY pairs. Eight bars or 4 cursors Indicateservo positions. (Position File Editor disabled)

SERVO 1EDITOR $249.00 (reg. $289) specialSame as above plus: Store and recall servo positions ondiskette. Create complex movement sequences.plus: SV_TSRI.EXE Pass servo position values to our TSRServo Controller Software from your programming language.plus: SVASM.obj An object module to convert integers tophysical movement.

For IBM AT & Compatibles or better. Call for details

RC ServoWare9205 Turtledove Lane Gaithersburg, MD 20879

(301)926.8583


Advertisers' IndexRS# Page #

60 AMC Sales 51103 Altex Electronics Coy IV

- Amer. Inst. for Comp. Sci....7662 Archon 5254 BG Micro 5

Binary Technology 59Brunelle Instruments 65

- CIE 90,Cov.III63 C&S Sales 80- Cable Ready Company 88

64 Capital Electro 7665 Consumertronics 6166 Cottage Resources Corp 7167 Covox 1088 Datahut Coy. II68 Design Computation 55- Grantham 28

69 Hampshire Industries 7770 Herne Data Systems 5271 Hoops -Ware 7172 Iota Systems 7773 Interactive Image Tech. 774 KGP 59- Kelvin Electronics 65- IS Electronics 73

75 Laser Group 7476 Lifeforce Technology 5577 MCM Electronics 23- MK Electronics 74

78 Mental Automation 2479 Merrimak Valley 5280 Microsystems Development 7681 Motron Electronics 71- NRI Schools 13

99 PC Boards 24- Parrallax 39

83 Photronics 6584 Praire Digital Inc 4085 Pseudo 8386 RC Servos 8987 Safesoft Systems 8889 Sayet 8361 Software + 73- Scrambling News 59

Skyvision, Inc 88- Software Science 88

90 Suncoast Technology 6991 URDA 8692 U.S. Cyberlab 8493 Ultra -X 10140 Unicorn Electronics 9

95,96 Vail Silicon Tools 74,8697 Viejo Publications 5198 Worldwide Cable 69


If You're SeriousAbout a Future in

Electronics, Ensure thatFuture with the BestEducational Training

Available.

FREE!SEND FOR YOUR CIE HOMESTUDY COURSE CATALOG ANDRECEIVE A FREE 24 PAGE CIEELECTRONICS SYMBOL HAND30010

Includes hundreds of the most frequentlyAused electronic symbols. Published byCIE exclusively for our students andalumni. Yours free when yourequest a CIE Course Catalog.

pi II P. Of 74111A

I f you want to learn about electron-ics, and earn a good income with thatknowledge then CIE is your besteducational value.

CIE's reputation as the worldleader in home study electronics isbased solely on the success of ourgraduates. And we've earned thatreputation with an unconditionalcommitment to provide our studentswith the very best electronicstraining.

Just askany of the150,000 -plusgraduates ofthe ClevelandInstitute ofElectronicswho areworking inhigh -payingpositions withaerospace,computer,medical,automotiveand communi-cation firmsthroughout theworld.

They'll tell you success didn'tcome easy...but, it did come.... thanksto CIE. And today, a career in elec-tronics offers more opportunities andgreater rewards than ever before.

CIE PROVIDES YOU WITH ALEARNING METHOD SOGOOD, IT'S PATENTED.CIE's Auto -programmed lessons are aproven learning method for buildingvaluable electronics career skills. Eachlesson is designed to take you step-by-step and principle -by -principle. Andwhile all CIE lessons are designed forindependent study, CIE's instructorsare personally available to assist you

with just a toll -free call. Theresult is practicaltraining... thekind of experi-ence you can putto work in today'smarketplace.

ito

)14Pc .11;

..

CIE's COMMITTED TO BEINGTHE BEST....IN ONEAREA.... ELECTRONICS.CIE isn't another be -everything -to -everybody school. We teach only onesubject and we believe we're the bestat what we do. Also, CIE is accreditedby the National Home Study Council.And with more than a 1,000 gradu-ates each year, we're the largesthome study school specializingexclusively in electronics. CIE hasbeen training career -minded studentslike yourself for nearly 60 years andwe're the best at our subjectELECTRONICS ... BECAUSE IT'S THEONLY SUBJECT WE TEACH!

LEARN BYDOING...WITHSTATE-OF-THE-ARTFACILITIESANDEQUIPMENT.In 1969, CIE

pioneered the first Electronics Labora-tory course and in 1984, the firstMircoprocessor Laboratory course.Today, no other home study schoolcan match CIE's state-of-the-art equip-ment and training. And all yourlaboratory equipment, books, andlessons are included in your tuition.It's all yours to use while you study athome and for on -the -job aftergraduation.

PERSONALIZEDTRAINING....TO MATCH YOURBACKGROUND.While some of our students have aworking knowledge of electronicsothers are just starting out. That'swhy we've developed twelve careercourses and an A.A.S. Degree programto choose from. So, even if your notsure which electronics career is bestfor you, CIE can get you started with

WHY CHOOSE CIE FOR YOUR TRAINING? 150,000 successful graduates from every country around the world. Only CIE rewards you for fast study. CIE offers an Associate Degree

program based on actual study time used. The faster you complete yourdegree the less your overall tuition.

State-of-the-art laboratory equipment is yours to keep and it comesassembled, ready for hands-on experiments.

Approved for educational benefits under the G.I. Bill for veterans and othereligible persons.

Upon graduation, CIE offers free preparation to pass the CertifiedElectronics Technician Exams.

core lessons applicable to all areas ofelectronics. And every CIE course youtake earns you credit towards comple-tion of your Associate in AppliedScience Degree. So you can worktoward your degree in stages or asfast as you wish. In fact, CIE is theonly school that actually rewards youfor fast study, which can save youthousands of dollars.

SEND TODAY FOR YOUR CIE COURSECATALOG AND WE'LL SEND YOU AFREE 24 PAGE CIE ELECTRONICSSYMBOL HANDBOOK!

r 11 Num in NI El IN me El

YE S!. I want to get started.Send me my CIE school catalog includ-ing details about the Associate DegreeProgram. (For your convenience, CIEwill have a representative contact you -there is no obligation.)

A029Name:

Address:

City: State:

Zip: Ages

Phone No. (

Check box for G.I. Bulletin BenefitsHI Veteran H Active Duty

ILIALigPCLEVELANDINSTITUTE OFELECTRONICS1776 East 17th StreetCleveland, Ohio 44114(216) 781-9400

A school of thousands.A class of one.

Since 1934.

lomm=========mmoll

TO CIDER (800) 531-5369 rAX (512) 637-3264 TO ORDER (800) 531-5369 FAX (512) 637-3264 TO ORDER (800) 531-5369 F l (512) 637-3264 TO ORDER 1800) 531-5369 FAX (5121 637-32E4

A ItexElectronicsInc,TO ORDER CALL 1(800) 531-5369 t VISA

,MasterCard

MAIL ORDER DEPT., 11342 IH-35 NORTH, SAN ANTONIO, TX 78233 - (512) 6373200; HOURS 7AM-BPM kl-F, 10-5PM SAT. FAX (512) 637-3264 MIMIM I I

TERMS: No surcharges on credit cards Fa C 0 D orders add $5 C 0 D orders are cash a certified check only. Minimum C.O.D. cider is $25. P.O.'s accepted horn approved accounts. Government,

purchase orders welcane. FAX your order tor faster service Al orders under $99 will be assessed a $3 handling charge. Orders over $99 or more no handing charges. AM shipping charges are

F.O.B. San Antonio, Texas and MI be added to invoice. Texas residents add 8 114% sales tax. Al returns require RMArt and we ask Oral all returns are sent bade In the same condition in which

lee eel be assessed on product that is returned n non-resaleabie condition Pnces and product descnplons subied to change. CALL FOR CURRENT PRICING. Products are tademarks of their

respectve companies We are not responsible for typographical errors. In a hurry? Federal Express your order. 2nd Day Economy - $8 up to 20Ibs. OvernightPnonty $17.50 up bo 2Clbs.

MOTHER BOARDS

MB286-12

M13286-16

1,113386-25

MB386-33C

MB486-33

12 MHz 286 MiniMotherboard

16 MHz 286 Mini

Motherboard

386 25 MHzMotherboard

386 33 MHz

Motherboard486 33 MHz

Motherboard

$99

$109

$229

$459

$799

CALL NOW1(800) 531-5369

FOR THE NEW ALTEX CATALOG

MEMORY BOARDS

All memory boards come with 0/K Call forpricing with memory

Perth

IFC-47 A

IFC-60

IFC-60A

1FG-61

IFC-62

IFC-64

MEMO -576

DescriptionBOCA 129K ATMemory BoardAT Plus - Up to

8 MEG RAMAT Memory Board $119

8 MEG Using SIMMSAT Memory Board $119

with I/O - up to 4 MEGPS -2 MOD 50 $119

60 EMS up to 2 MEGPS -2 - EMS

up to 2 MEG

576K Ramboard

Each

$79

$119

$99

$23

IIT MATH CO -PROCESSORS

2C87-12

2C87-203C87-16SX

3C87-20SX

3C87-25SX3C87-25

3C87-33

For 286 up to 12 5 MHzFor 286 up to 20 MHzFor 386SX up to16 MHz

For 386SX up to20 MHz

For 386SX up to 25 MHzFor 386 up to 25 MHzFor 386 up to 33 MHz

$78

84

100

113

125

150

163

CALL FOR PRICING ONDYNAMIC MEMORY

AND MEMORY MODULES

DISK CONTROLLER BOARDS

IFC-27-2

WC -27X

IFC-28

Description Each

2 Floppy Controller $13

Board PC/XTDisk I/O Board Serial, $25

Parallel, Clock, Game PC/XTFixed Disk MFW2 Floppy $55

Controller ATAT 2 IDE, 2/Floppy Controller 919

XT 2/IDE Controller 969

XT MFM Hard Drive $47

Controller Board

ST -01 8 Brt SCSI Controller

ST -02 8 Brt SCSI/FloppyController Board

IN -2000 16 Bit SCSI Hard/Floppy

EXPANSION BOARDSPAOWC -12

IFC-12A

DescriptionSerial Board PC/XTSecond Serial Port Kit forIFC-12

IFC-25 2 Serial, Parallel CameBoard XT/AT

WC -13 Parallel Board XT/ATIFC-19 Clock Board PC/XT

WC -19B Chipchip for PC/XT

IFC-20 Game BoardXT/AT 2 Ports

IFC-70 BOCA 2 Serial 2 ParallelI/O Board

IFC-73 BOCA 2 Serial 1 Parallel

& Clock BoardIFC-75 BOCA 2 Serial 1 Parallel

MCA I/O BoardIFC-76 BOCA Parallel Port MCA

I/O Board

COMMUNICATION BOARDS

Perth

MS -400A

DescriptionMulti -Serial Boardfor PC/AT

MS -422A Dual RS -232/422

Serial Card for PC/ATMU440 Multi -User BoardLCS-8880 4 -Port Multi -Terminal Card

929

947

9189

Each

911

$6

916

gg

$10

$24

99

949

$49

$99

$65

Each

$89

$69

$139

$75

VIDEO BOARDS

IFC-32

IFC-33

WC -42

WC -42C

VG -7000

Mono Boardw/printer port XT/AT

Color Graphicsw/printer port XT/AT640x480 VGA Card

BOCA Super VGA CardSuper VGA w/5121(

916

$25

959

$139

$85

COMPUTER CASES

ParMSTC-12STC-05

STC-10

STC-08

STC-18

STC-16

RM9502

R E1420

RE1520

$139

DescriptionBaby AT CaseBaby Vertical w/230 Watt

Power SupplyRegular AT Case w/230Power Supply

Medium Vertical Casew/230 Watt Power SupplyRegular Vertical w/250

Watt Power SupplyRegular Verticalw/250 Watt Power Supply

Monochrome VGA(800 x 350. 400, 480)Super VGA (1024 x 768) $359

Unlimited Colors15' Super VGA Monitor $469

(Noninterlaced up to 1024x7681

7gi-v

Each

$83

$89

$95

$119

$133

$136

PS -150 150 watt XT Power Suppy $32

PS-150UL Same as PS -150 - UL Listed $69

PS -200M 200 watt XT power Supply $36

PS-200MUL Same as PS -200M - UL Listed$89P5-200 200 watt AT Power Supply 942

PS-200UL Same as PS -200 UL Listed $89

PS -220 220 watt Vertical CasePower Supply 979

PS-230UL 230 watt Vertical Case $99

Power Supply UL ListedPS-200MINI 200 watt Baby Vertical Case

Power Supply $59

DISK DRIVES

DD 0-04

DDD-05

DDH-06

DD H-09

DDH-10

DDH-11

RAIL01

FP-BLK

5 1/4 inch DSDD3601( black faceplate 359

5 1/4 inch DSDD

360K beige faceplate $59

5 1/4 inch DSHD1 2MB beige faceplate $59

3 1/2 inch 720K beigew/brkt $59

3 1/2 inch 1 44MBbeige w/brkt $59

Same as DDH-10 without 955

5-1/4' mounting bracketFits in 3-1/2' bayAT Drive Rail Kit $1.99

1/2 Height BlackFaceplate $2.49

MON-05 Monochrome TTL

Amber 12'MON-06 Paper White TTL 14'MON-10 CGA/RGB

(640 x 240)14'MON-07 VGA .41 Dot Pitch

(640 x 480)14'

$89

$112

$219

$239

KEYBOARDS

Limited QuantitiesKBY-60 AT Style 10 Function Keys $19

XT or AT

Perth Description Each

KBY-39 Enhanced Style $49

12 Function Keys XT or ATK-156 (XT,AT) $35

101 keys with regular footprint for XT or AT

Size: 20 1/210 7 7/8'W x 1 13/16'HK-160 Narrow Footprint $36

101 keys XT or AT.Size. 181/2'L x 6 1/2'W x 1 5/16'HK-158 Small Footprint $43

101/102 keys. 22 percent smaller than regularfootprint.Size: 15 3/4'L x 7 7/8'W x 1 13/16'HK-158-1 Small Footprint

Spanish Language$47

HARD DRIVES

ST -251 40 MB MFM 28 MSHard Drive 5.1/4'

ST -351A 40 MB IDE 28 MS

Hard Drive 3.1/2'ST -3120A 105 MB IDE 15 MS

Hard Drive 3.1/2' $ 359

ST -3144A 120 MB IDE 19 MSHard Drive 3-1/2' 9419

ST -1239A 210 MB IDE 15 MS

Hard Drive 3.1/2' 9649

ST -296N 84 MB SCSI 19 MSHard Drive 5.1/4' $369

ST -1239N 204 MB IDE 15 MS $649

Hard Dove 3.1/2'ST -1460N 426 MB SCSI 14 MS $1399

Hard Drive 3.1/2'

$259

$219

TO ORDER (8001 531-5369 FAX (512) 637-3264 TO ORDER (800) 531-5369 FAX (512) 637-3264 TO ORDER (800) 531-5369 FAX (512) 637-3264

-4

Oerr

0Fo

artloa

in

-n

crt

cr,


Computer-Craft-1992-05.pdf - World Radio History

Documents

Transcript of Computer-Craft-1992-05.pdf - World Radio History