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Materi Perkuliahan Bahasa Inggris
http://www.google.co.id/imghp?hl=id&tab=ii
COMPILED BYLau la Innas ari, S.S., M.Hum
STMIK
BANJARBARUEVERYTHINGABOUTCOMPUTER
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Unit 1
Getting to know the computer
What is a computer?
A computer is an electronic device that manipulates information, or "data." It has the ability to
store, retrieve, and process data. You can use a computer to type documents, send email, and
browse the internet. You can also use it to handle spreadsheets, accounting, database management,
presentations, games, and more.
The computer is no longer a novelty today. It is something that is highly functional and useful not
only to scientists, managers, businessmen, professionals, and government officials, but also to
students like you.
The world is changing because of the computer. The computer can do almost any routine or
systematic procedure or operation involving information, so that people can have more time to do
what they do best - think.
The term computer has many definitions. The easiest to understand and remember is:A computer is
an electronic device designed to manipulate data so that useful information can be generated. Data
may be defined as any collection of facts. By this definition, data may refer to both numerical and
non-numerical information. Data processing is the manipulation of data into a more useful form. It
involves the collection, processing, and distribution of facts and figures to achieve a desired result. It
may also involve the classification of data and the transmission of data from one place to another.
All the operations involved in data processing may have been performed by some kind of a machine
or a computer, although some of them could have been carried out manually. Data processing
system refers to the equipment or devices as well as procedures by which the result is achieved. In
short, a computer is part of a data processing system.
A computer accepts information (in the form ofdigitalizeddata) and manipulates it for some result
based on a program or sequence of instructions on how the data is to be processed. Complex
computers also include the means for storing data (including the program, which is also a form of
data) for some necessary duration. A program may be invariable and built into the computer (and
called logic circuitry as it is on microprocessors) or different programs may be provided to the
computer (loaded into its storage and then started by an administrator or user). Today's computers
have both kinds of programming.
What are the Different Types of Computers?
When most people hear the word "computer" they think of a personal computer such as a desktop
or laptop computer. However, computers come in many shapes and sizes, and they perform many
different functions in our daily lives. When you withdraw cash from an ATM, scan groceries at the
store, or use a calculator, you're using a type of computer.
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Desktop Computers
Many people use desktop computers at work, home, school, or the library. They can be small,
medium, or large in style, and usually sit on a desk. Once you add a monitor, mouse, and a keyboard,
you have what is typically known as a desktop computer.
Most desktop computers are easy to upgrade and expand, or add new parts. Another benefit ofdesktop computers is the cost. If you compare a desktop and a laptop with the same features, you
will most likely find that the desktop computer is priced lower.
Some desktop computers have a built-in monitor to save space. These are often called all-in-one
desktop computers.
Laptop Computers
The second type of computer that you may be familiar with is a laptop computer, or laptops as they
are often referred to. Laptops are battery or AC-powered personal computers that are more
portable than desktop computers, allowing you to use them almost anywhere.
Since a laptop is smaller than a desktop, it's more difficult to accessthe internal components. That
means you may not be able to upgradethem as much as a desktop. However, it's usually possible to
add more RAM or a bigger hard drive. A laptop computer is sometimes called a notebook
computer because of its size.
Servers
A server is a computer that "serves up" information to other computers on a network. Many
businesses have file servers that employees can use to store and share files. A server can look like a
regular desktop computer, or it can be much larger.
Servers also play an important role in making the internet work: they are where web pages arestored. When you use your browser to click a link, a web server delivers the page you requested.
Other Types of Computers
Today, there lots of everyday devices that are basically specialized computers, even though we don't
always think of them as computers. Here are a few common examples:
Tablet Computers: These use a touch-sensitive screen for typing and navigation. Since theydon't require a keyboard or mouse, tablet computers are even more portable than laptops.
The iPad is an example of a tablet computer.
Mobile Phones: Many mobile phones can do a lot of things a computer can do, such asbrowsing the internet or playing games. These phones are often called smart phones.
Game Consoles: A game console is a specialized kind of computer that is used for playingvideo games. Although they are not as fully-featured as a desktop computer, many newer
consoles, such as the Nintendo Wii, allow you to do non-gaming tasks like browsing the
internet.
TVs: Many TVs now include applications (or apps) that let you access various types of onlinecontent. For example, you can view your Facebook news feed or watch streaming movies on
Netflix. ( Source: 1998-2012 Goodwill Community Foundation, Inc.)
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READING COMPREHENSION
A. Answer the questions below.1. What is a computer?2. What is the ability of a computer?3. What are the uses of a computer?4. How does a computer work?5. What are different types of computers?
B. Find the description of these words1. Manipulate2. Digitalized3. Logic circuitry4. Microprocessors5. Built-in6. Access7. Upgrade8. Serve-up
C. Look at the phrase digitalized data. It means data which has digital form. Digitalizedis anadjective which modifies the noun data.Explain the meaning of these phrases.
1. Personal computer2. Built-in monitor3. Notebook computer4. File server5. Web page6. Specialized computer7. Touch-sensitive screen8. Fully-featured computer9. Non-gaming tasks10.News feed
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Unit 2
The history of computers
The first computer
The first substantial computer was the giant ENIAC machine by John W. Mauchly and J. Presper
Eckert at the University of Pennsylvania. ENIAC (Electrical Numerical Integrator and Calculator) used
a word of 10 decimal digits instead of binary ones like previous automated calculators/computers.
ENIAC was also the first machine to use more than 2,000 vacuum tubes, using nearly 18,000 vacuum
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tubes. Storage of all those vacuum tubes and the machinery required to keep the cool took up over
167 square meters (1800 square feet) of floor space. Nonetheless, it had punched-card input and
output and arithmetically had 1 multiplier, 1 divider-square rooter, and 20 adders employing
decimal "ring counters," which served as adders and also as quick-access (0.0002 seconds) read-
write register storage.
The executable instructions composing a program were embodied in the separate units of ENIAC,which were plugged together to form a route through the machine for the flow of computations.
These connections had to be redone for each different problem, together with presetting function
tables and switches. This "wire-your-own" instruction technique was inconvenient, and only with
some license could ENIAC be considered programmable; it was, however, efficient in handling the
particular programs for which it had been designed. ENIAC is generally acknowledged to be the first
successful high-speed electronic digital computer (EDC) and was productively used from 1946 to
1955. A controversy developed in 1971, however, over the patentability of ENIAC's basic digital
concepts, the claim being made that another U.S. physicist, John V. Atanasoff, had already used the
same ideas in a simpler vacuum-tube device he built in the 1930s while at Iowa State College. In
1973, the court found in favor of the company using Atanasoff claim and Atanasoff received the
acclaim he rightly deserved.
Progression of Hardware
In the 1950's two devices would be invented that would improve the computer field and set in
motion the beginning of the computer revolution. The first of these two devices was the transistor.
Invented in 1947 by William Shockley, John Bardeen, and Walter Brattain of Bell Labs, the transistor
was fated to oust the days of vacuum tubes in computers, radios, and other electronics.
The vacuum tube, used up to this time in almost all the computers and calculating machines, had
been invented by American physicist Lee De Forest in 1906. The vacuum tube, which is about the
size of a human thumb, worked by using large amounts of electricity to heat a filament inside the
tube until it was cherry red. One result of heating this filament up was the release of electrons intothe tube, which could be controlled by other elements within the tube. De Forest's original device
was a triode, which could control the flow of electrons to a positively charged plate inside the tube.
A zero could then be represented by the absence of an electron current to the plate; the presence of
a small but detectable current to the plate represented a one.
Vacuum tubes were highly inefficient, required a great deal of space, and needed to be replaced
often. Computers of the 1940s and 50s had 18,000 tubes in them and housing all these tubes and
cooling the rooms from the heat produced by 18,000 tubes was not cheap. The transistor promised
to solve all of these problems and it did so. Transistors, however, had their problems too. The main
problem was that transistors, like other electronic components, needed to be soldered together. As
a result, the more complex the circuits became, the more complicated and numerous the
connections between the individual transistors and the likelihood of faulty wiring increased.
In 1958, this problem too was solved by Jack St. Clair Kilby of Texas Instruments. He manufactured
the first integrated circuit or chip. A chip is really a collection of tiny transistors which are connected
together when the transistor is manufactured. Thus, the need for soldering together large numbers
of transistors was practically nullified; now only connections were needed to other electronic
components. In addition to saving space, the speed of the machine was now increased since there
was a diminished distance that the electrons had to follow.
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Mainframes to PCs
The 1960s saw large mainframe computers become much more common in large industries and with
the US military and space program. IBM became the unquestioned market leader in selling these
large, expensive, error-prone, and very hard to use machines.
A veritable explosion of personal computers occurred in the early 1970s, starting with Steve Jobs
and Steve Wozniak exhibiting the first Apple II at the First West Coast Computer Faire in San
Francisco. The Apple II boasted built-in BASIC programming language, color graphics, and a 4100
character memory for only $1298. Programs and data could be stored on an everyday audio-cassette
recorder. Before the end of the fair, Wozniak and Jobs had secured 300 orders for the Apple II and
from there Apple just took off.
Also introduced in 1977 was the TRS-80. This was a home computer manufactured by Tandy Radio
Shack. In its second incarnation, the TRS-80 Model II, came complete with a 64,000 character
memory and a disk drive to store programs and data on. At this time, only Apple and TRS had
machines with disk drives. With the introduction of the disk drive, personal computer applications
took off as a floppy disk was a most convenient publishing medium for distribution of software.
IBM, which up to this time had been producing mainframes and minicomputers for medium to large-
sized businesses, decided that it had to get into the act and started working on the Acorn, which
would later be called the IBM PC. The PC was the first computer designed for the home market
which would feature modular design so that pieces could easily be added to the architecture. Most
of the components, surprisingly, came from outside of IBM, since building it with IBM parts would
have cost too much for the home computer market. When it was introduced, the PC came with a
16,000 character memory, keyboard from an IBM electric typewriter, and a connection for tape
cassette player for $1265.
By 1984, Apple and IBM had come out with new models. Apple released the first generation
Macintosh, which was the first computer to come with a graphical user interface(GUI) and a mouse.The GUI made the machine much more attractive to home computer users because it was easy to
use. Sales of the Macintosh soared like nothing ever seen before. IBM was hot on Apple's tail and
released the 286-AT, which with applications like Lotus 1-2-3, a spreadsheet, and Microsoft Word,
quickly became the favourite of business concerns.
That brings us up to about ten years ago. Now people have their own personal graphics workstations
and powerful home computers. The average computer a person might have in their home is more
powerful by several orders of magnitude than a machine like ENIAC. The computer revolution has
been the fastest growing technology in man's history.
(Source: http: //www.computerhistory.org/timeline/index.page)
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Unit 3
Characteristics of a computer
A computer is a device with remarkable efficiency and speed. In fact, it is described as an intelligent
machine. But you must not forget that it is just a tool for man to use. It may be a powerful tool, but
it is still a tool nonetheless.
All computers are designed to perform the same basic functions and these characteristics are
mainly technical rather than aesthetic. Computers may differ in design, but in order to legally be
placed into the computing market they must reach certain consumer expectations or will not be
acceptable.
Most consumers are looking for a computer that is reliable, yet if the product is on the market then
it is bound to have undergone and passed the numerous technological tests before release.
Therefore, all computers are reliable and meet these characteristics, but it just depends upon the
efficiency of the users' computer skills as to whether they remain satisfied with their purchase.
What Are The Characteristics Of A Computer?
It is interesting to point out that as the basic characteristics of computers are all the same,
technological problems with computers originate from human error and not faults within the
hardware.
Speed
The computer was invented as a high-speed calculator. This has led to many scientific projects which
were previously impossible. The control of the moon landing would not have been feasible without
computers, and neither would today's more scientific approach to weather prediction. If we want
tomorrow's forecast today (and not in six months time) meteorologists can use the computer to
perform quickly the necessary calculations and analyses. When making flight reservations we want
to know well in advance of take-off that a seat will be available - if it is not, then we have time to
make other arrangements. The ability to get answers isfast enough so that one has time to take
action on them (or to make alternative plans, as in the case of airline reservations) makes real-time
computing possible.
Electrical pulses travel at incredible speeds and, because the computer is electronic, its internal
speed is virtually instantaneous. We do not talk in terms of seconds or even milliseconds. Our units
of speed are the microsecond (millionths), the nanosecond (thousand-millionths) and latterly even
the picosecond (million-millionths). A powerful computer is capable of adding together two 18-digit
number in 300 to 400 nanoseconds.
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Consider two examples from non-numerical environments. The manual indexing of the complete
works of Thomas Aquinas (approximately 13 million words) would have taken 50 scholars about 40
years to accomplish. With the aid of a computer a few scholars did it in less than one year.
Fingerprint identification, in time to catch a criminal before he flees the country, would be
impossible without computers. The first example enables us to enjoy knowledge that would
otherwise be unobtainable within our own lifetime. In the second example, the police gain time to
act.
Storage or Memory
The speed which computers can process large quantities of information has led to the generation of
new information on a vast scale, in other words, the computer has compounded the information
'explosion'. How can people cope with it? We can't, but computers can. But where do they keep it
all?
As a human acquires new knowledge, the brain subconsciously selects what it feels to be important
and worth retaining in its memory, and relegates unimportant details to the back of the mind or just
forgets them. In computers, the internal memory of the CPU is only large enough to retain a certain
amount of information. It is therefore, impossible to store the records inside the computer, forexample, of every Premium Bond and the names and address of their owners. All of this data is
stored outside of the memory of the CPU, on auxiliary or secondary storage devices. Small sections
of the total data can be accessed very quickly by the CPU and brought into the main, internal
memory, as and when required for processing.
The internal memory (in CPU) is built up in 1 K or K modules, where K equals 1024 storage locations.
Babbage's Analytical Engine would have been capable of holding 1000 numbers, each of 50 digits.
Computers come in many sizes. Many small micro-computers have an 8 K or 16 K store whilst 'super
computers', such as the CDS CYBER 205 may have up to 1024 K stores (i.e. 1024 * 1024 locations).
Accuracy
In spite of misleading newspaper headlines, the computer's accuracy is consistently high. Errors in
the machinery can occur but, due to increased efficiency in error-detecting techniques, these seldom
lead to false results. Almost without exception, the errors in computing are due to human rather
than to technological weaknesses, i.e. to imprecise thinking by the programmer, or to inaccurate
data, or to poorly designed systems.
Versatility
Computers seem capable of performing almost any task, provided that the task can be reduced to
series of logical steps. For example, a task such as preparing a payroll or controlling the flow of traffic
can be broken down into a logical sequence of operations, whereas comparing the tones of a turner
with a Vermeer cannot. Yet the computer itself has only limited ability and, in the final analysis,actually performs only four basic operations:
It exchanges information with the outside world via I/O devices, It transfers data internally within the CPU, It performs the basic arithmetical operations, It performs operations of comparison.
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In one sense, then, the computer is not versatile because it is limited to four basic functions. Yet,
because so many daily activities can be reduced to interplay between these functions, it appears
that computers are highly ingenious. Programming is the craft or reducing a given problem into
interplay between these few operations.
Automation
A computer is much more than an adding machine, calculator or check-out till, all of which require
human operators to press the necessary keys for the operations to be performed. Once a program is
in the computer's memory, the individual instructions are then transferred, one after the other, to
the control unit for execution. The CPU follows these instructions until it meets a last instruction
which says 'stop program execution'. When Babbage claimed that his Analytical Engine would be
automatic, he meant that once the process had begun, it would continue without the need for
human intervention until completion.
Diligence
Being a machine, a computer does not suffer from the human traits of tiredness and lack of
concentration. If 3 million calculations have to be performed, it will perform the 3 millionth withexactly the same accuracy and speed as the first. This factory may cause those whose jobs are highly
repetitive to regard the computer as a threat. But to those who rely on a continuous standard of
output, e.g., quality control in the refining of oil and other chemical processes, the computer will be
seen as a considerable help.
(Source: http://www.openlearningworld.com)
(1999-2011 OpenLearningWorld.com)
___________________________________________________________________________
READING COMPREHENSION
Answer the following questions
1. Why should a computer undergo several technological tests before release?2. Mention two advantages of the computers speed.3. What is the meaning of computers automation?4. What is information explosion?5. Why is a computer considered of being diligent?
Describe the following terms
1. Device2. Reliable3. High-speed calculator4.
Nanosecond5. Non-numerical environment
6. Due to7. Error-detecting techniques8. Poorly designed system9. CPU
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Unit 4
Computer applications
In this development of information technology everyone must be familiar with the using of
computers; the computer has important applications in helping users accomplish a task. Computer
Application is a computer program written in a programming language and is used to solve a specificproblem. This application serves to perform jobs according to user needs.
Types of computer applications
Network Applications. Computer Networking is the coordination of communication within a
particular system between central (server) and some of its members. Network Topology is the
pattern of relationships between terminals in a computer network. There are various types of
network topology.
Graph Applications. There are many types of computers with different graph applications. Computer
graphics applications beginning its development began in the late 1950s and early 1960s. It is a
computer program used to draw a picture that gives a new dimension in the field of computertime. There are two obvious ways to enter information into the computer graphics into an
application, namely:
1. Direct Graphics Programming, by writing into the programming language.2. Digitizing (or Graphics) Tablets, by using the mouse.
Animation. Each computer may be having difference specification, so the choosing computer
components must be carefully. It is a form of art that appears spontaneously to generate life
movement on an object. To achieve these effects, animators have to construct a series of frames /
images of a subject, that each of the next frames is slightly different from the previous frame.
Animation is one of computer applications which intended to give more interesting when using
computer.
Computer with a lot of animation runs slowly than one with poor of animation, so it must increase
computer performancewhich uses many animations. There are actually several different functions
to produce computer-based animation and one thereof is an animated three-dimensional (3D). One
rather than the technique is to create an object which is then adjusted and moved, in which
ultimately will produce a complete 3D animation. Another function is to create computer animations
using a standard computer paint tools to paint the frames a single prior to the merger. This is then
stored as an image file.
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Web Applications. A web application is a part of computer applications, but web application is
related to LAN MAN WAN concept which is part of the internet as a community computer network
that provides services http (World Wide Web). Thus, the technical definition of the World Wide Web
is all the resources and all the internet users that use HTTP (Hypertext Transfer Protocol). WWW is
the most exciting applications on the Internet and applications such as email is very important and
widely used. This application is sometimes called "The Killer Application" or "the world is at your
fingertip" because we can get so easy to notice with not just text and even images, and multimedia.Every computer has a CPU as main brain, one ofmain components of a CPU is for support the web
applications and computer development.
In this application a lot of convenience can be done such as:
order or purchase an item online register online reach multimedia, etc
Network technology both cabling and wireless issues bought us connects everywhere. Notices are
placed on the WWW called "Home Page" and every home page has the address of each. In order to
attract users' attention so that the homepage can be visited, then we have them shape it interestingand there are many clear edicts. It is necessary in this field of art, so that the world of advertising
and commerce would be better. The computer applications especially web application most
commonly used browser today is Netscape Navigator in the world other than Internet Explorer. Web
application become the largest used application because the role of internet history. Without
internet web application could not interact with people.
Application of Education
Computer Assisted Instruction (CAI). Computers are directly used in the learning process, asa substitute teacher or a book. Some CAI applications are: Drill and
Practice, Tutorials, Simulation.
Computer Managed Instruction (CMI). The teachers use computers to plan for college, thestudents adapted to the conditions, which consisted of computer-assisted learningprograms, reading, and exams.
Computer Assisted Testing (CAT). Computers are used as test media. Many forms, rangingfrom simple where the computer (usually through the display) is used as a substitute for
examination questions in paper form, to the more advanced form, where the ability of
computers used to explore students' abilities in ways actively questioning.
Application of Business / Office. Another computer application is office application. This application
is used for business purpose, every business, large or small, to process large amounts of data in daily
operations. Data obtained from the payroll, customer invoicing and financial accounts, inventory
management, and account customers that all fees must be calculated, stored, classified, sorted,
retrieved, processed again, reported, communicated and disseminated at a time. Processing of suchdata is known as Business Data Processing or Data Processing (DP). If the processing is done by
computer, this is known as Electronic Data Processing (EDP). Now every office's employee must be
able operate computer, so they must know how to use computer to make their job easy.
DBMS (Data Base Management System). Computers also can be used as Effective in business
management. Through a computerized database management system (DBMS) and the SIM, a
manager or company executive can be assisted in making decisions about the entire business
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operation and to provide guidance and instructions to subordinates. DBMS types which common
used nowadays are relational database and RDBMS concept.
Application for a Certain Class
Air Traffic Control System Airline Reservation Systems
(Source: http://tutorial-computer.com/software/216-computer-applications)
___________________________________________________________________________
READING COMPREHENSION
1. What is Computer Application?2. What are the functions of animation application?3. Describe the computer networking.4. Describe the terms WWW and HTTP.5. What is Killer Application?
__________________________________________________________________________
Unit 5Peripherals
A peripheral (pronounced peh-RIHF-uh-ruhl, a noun truncation ofperipheral device,) is any computer
device that is not part of the essential computer (the processor, memory, and data paths) but is
situated relatively close by. A near synonym is input/output (I/O) device. Some peripherals mounted
in the same case with the main part of the computer are the hard disk drive, CD-ROM drive, and NIC.
Other peripherals are outside the computer case, such as the printer and image scanner, attached by
a wired or wireless connection.
Computer Peripherals
Computer peripherals are add-on hardware to the computer to expand its abilities or improve its
performance. By adding memory, computers are able to perform a lot better, or by adding video
cards, the computers graphics create more detail. These are just some of the peripherals, although
there is a lot more you can put on your PC, some of them may not be compatible.
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Compatibility maybe an issue to some of the peripherals and may even cause the worst outcome
the PC refuses to boot or the PC refuses to recognize the peripheral being added. The easiest way to
solve that would be figuring out where it is started and you can start from there.
Narrow down the problem and re-check the connections specially the cards you just added-in.
Checking the wires and screws make a difference. And every time you install a new add-on card, and
it suppose to be plug-and-play but it is not, maybe because you made a mistake in the installationprocess. Do not panic. Go through the whole process again and then try once more. If still nothing is
solve then maybe there might be a compatibility problem.
Technically, every piece of hardware inside your PC requires a driver to communicate and function
with the operating system, the software applications, and other hardware components in your
computer. Software drivers basically translate messages from and to the hardware in question and
the operating system, allowing your computer system to work as a whole theoretically. Generally,
though appearances may be deceiving, any computer system is actually made up of a bunch of
specialized pieces that do not communicate the low level language of other peripherals and,
therefore, needs a great deal of translation to be able to talk and work effectively with them.
These facts may not solve all the hardware problems you may run into, however, they should solve a
good number of them. The important thing to remember when trying to do any troubleshooting jobis that computers really are just logical devices and there is always a logical reason behind why
things just not suppose to react the way they are. Finding what is that reason and then putting the
right solution is not always easy, but if you approach the problem logically and work through it step-
by-step, there is a very good chance you will be able to solve it by yourself.
(Source: [email protected] 2003-2012; http://www.webopedia.com/,
Copyright 2012.www.computerotic.com)
___________________________________________________________________________
UNIT 6
Computer Capabilities and Limitations
We see computer everywhere: at home, in school, in the hospital, in the bank, in bookstores and
department stores, at recreation centers and in many other places. They are important pieces of
equipment and they help man in so many ways. Many people depend so much on computers. They
use computers to do their work, to have fun. To keep in touch with their loved ones, to store
important documents and so on. Why is this so? That is because computers are capable of doing so
many things.
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The following items are the capabilities of a computer:
Speed. The computer processes information very fast. Would you believe that computer can get the
average of a million sets of numbers in a few seconds by pressing a button? It is like getting the sum
or total of one hundred different sets of numbers in one click. With a speed reaching up to fifty
million operations per second, a computer can process data faster than any other machine designed
to perform a similar task. That is, adding two numbers is considered as one operation
Accuracy. The computer gives accurate results. Some scientists use the computer in their
experiments. The needed data for their experiments are processed in the computer. They can get
almost perfect and more accurate results through it. High-speed processing by a computer is
accompanied by high-accuracy results. A computer can be considered 100% accurate. The electronic
circuitry of computers is such that, when the machines are fed with correct instructions or data and
when the incoming data is error-free, the accuracy of the output is relatively assured.
Compact storage. The computer stores large amount of data and information. Most computers have
storage or accessories wherein the user can save information or document. These are called floppy
diskettes, hard disks and zip disks. A computer has the ability to store large amounts of data in
compact and easily retrievable form. It can store data at a very high speed.
Repetitiveness. A computer can perform the same operation a million times in exactly the same
way. The various operations are executed automatically by way of stored computer programs. The
computer enables one to restore or bring back any of his works. You try to bring your old work when
you want to make another copy of it, or when you want to change something in it. A computer
makes all these possible.
It is automatics. You dont have to wait long for a computer to do a certain job. Most of the time,
you just have to click a button and the computers processor will do the rest of the work.
The computer can do two things at the same time. You may open two or more programs at the
same time. You may work with the first one while you minimize or hide the other program.
Logical operations. The computer can make a decision based on alternative courses of action. The
decisions of a computer are, however, dependent on the programs prepared for it by the
programmer. A decision consists of two steps, namely:
a. Determining if a certain statement is true or false.
b. Based on the result of the first step, choosing one or the other course of action out of the
alternatives provided in the computer program.
Discipline means that a computer can self-check and self-operate. A computer self-checks when it
verifies the accuracy of its own work by means of a parity check. In a parity check, the computercounts the number of characters it has stored to make sure that there will be no loss of data during
processing. In self-operation, a computer is capable of executing instructions on its own, without
human intervention, once the program and the data are fed into the computer's memory.
The computer can be improved and upgraded. The computer is unlike other machines or appliances
that your parents discard or throw away when they do not function properly anymore. Today, it is
very easy to replace damaged and obsolete computer parts. You just have to go to the nearby
computer store or ask a service technician to do installation and repair work for your computer.
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Limitations of a Computer
However, the computer is not a super machine. Thus, it has its own limitations, like the following:
o The computer can only do what you tell it to do. Do not expect the computer to give yousomething which you never tell it to do. It will only give you what you ask it.
o It cannot generate information on its own. Your computer depends on you. It will not run unlessyou operate it. In the same way, it cannot give you information you need if you do not feed itwith the necessary data. While it is true that a computer has the capacity to put together
information from many sources, it can only do this if it has been programmed by man to do so.
o The computer will give you wrong information if you feed it with wrong data. The computercannot distinguish between correct data and wrong data. Thus, if you feed your computer with
wrong data, it will result with the computer giving wrong information.
o The computer cannot correct wrong instruction. If you give the computer wrong instruction, itwill not able to do anything to correct it. It will only stop functioning. Then, the computer will
depend on you to correct your mistake. A computer cannot correct wrong instruction. If a
computer is fed with incorrect instructions or data, whether intentionally or unintentionally, it
does not have the capability to detect mistakes and correct them. In computer language, this is
known as GIGO (garbage in garbage out). This means that a computer that has been fed with awrong set of instructions or data will similarly produce wrong information and wrong decisions.
Therefore, any corrections must be done by the programmer.
(Source: ///Cybertech/Luz Pingol 2010 SlideShare Inc.; ///people/denz/siplever Copyright 2008-
2012 Webika Ltd.)
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UNIT 7
Hardware and software
Books provide a useful analogy. The pages and the ink are the hardware, while the words, sentences,
paragraphs, and the overall meaning are the software. A computer without software is like a book
full of blank pages -- you need software to make the computer useful just as you need words to
make a book meaningful. Hardware refers to objects that you can actually touch, like disks, disk
drives, display screens, keyboards, printers, boards, and chips. In contrast, software is untouchable.
Software exists as ideas, concepts, and symbols, but it has no substance.
Hardware
Hardware refers to the physical elements of a computer. It is also referred to as the machinery or
the equipment of the computer. Examples of hardware in a computer are the keyboard, the
monitor, the mouse and the processing unit. However, most of a computer's hardware cannot beseen; in other words, it is not an external element of the computer, but rather an internal one,
surrounded by the computer's casing. A computer's hardware is comprised of many different parts,
but perhaps the most important of these is the motherboard. The motherboard is made up of even
more parts that power and control the computer.
In contrast to software, hardware is a physical entity, while software is a non-physical entity.
Hardware and software are interconnected, without software, the hardware of a computer would
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have no function. However, without the creation of hardware to perform tasks directed by software
via the central processing unit (box), software would be useless.
Software
Software refers to the operating system and allutilityprograms that manage computerresources at
a low level. Software is generally divided into systems software and applications software.
Applications software comprises programs designed for an end user, such as word processors,
database systems, and spreadsheet programs. Systems software includes compilers, loaders, linkers,
and debuggers.
The term "software" is sometimes used in a broader context to describe any electronic media
content which embodies expressions of ideas such as film, tapes, records, etc. Software is the
electronic instruction that tells the computer to do a task.
Software, commonly known as programs, consists of all the electronic instructions that tell the
hardware how to perform a task. These instructions come from a software developer in the form
that will be accepted by the operating system that they are based on. For example, a program that is
designed for the Windows operating system will only work for that operating system. Compatibility
of software will vary as the design of the software and the operating system differ. A software that is
designed for Windows XP may experience compatibility issue when running under Windows 2000 or
NT.
Software can also be described as a collection of routines, rules and symbolic languages that direct
the functioning of the hardware.
Software is capable of performing specific tasks, as opposed to hardware which only perform
mechanical tasks that they are mechanically designed for. Practical computer systems divide
software systems into three major groups:
1. System software: Helps run computer hardware and computer system. Computer softwareincludes operating systems, device drivers, diagnostic tools and more.
2. Programming software: Software that assists a programmer in writing computer programs.3. Application software: Allows users to accomplish one or more tasks.
(Source: http://www.webopedia.com)
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UNIT 8
Mainframe
What is Mainframe?
As we all know the term mainframe when said to a layman would give a feeling of a large computer,but the question arise how large it is and what is the specialty of these mainframes. The answer to
this question lies in the term "Mainframe" itself. As the name implies mainframe is the main
computer with all units processing. Communications are built into a frame and hence the name
Mainframe, which thereby denotes a very large computer.
Mainframes have huge processing and storage capacity. The development cost involved with
mainframes is also very huge and therefore mainframes are manufactured only by very large
companies. Mainframe gets its usage and applications in banking and financial sectors where large-
scale operation with millions of records per day is involved.
Apart from the above there is also enterprise class mainframe integration which has greater features
and ability of connecting mainframe data sources to distributed platforms. Thus, with specific,specialized and powerful features of mainframes like security, high performance, reliability,
scalability and manageability are achieved and provided to distributed applications using mainframe
resources.
History and Evolution of Mainframes:
Some of the early mainframes which were developed starting from the year of 1942 are ENIAC,
MARK1, BINAC, UNIVAC. ENIAC is also called as electronic numerical integrator and calculator was
developed in the year 1942. This mainframe machine weighed in tones and consumed enormous
electric power. It had thousands of vacuum tubes, relays resistors, capacitors, and inductors inside it.
In the year 1951, UNIVAC-I was developed specially for the US Census Bureau. The major differencebetween UNIVAC and ENIAC was the processing of digits. In UNIVAC, processing was done in serial
mode, yet the speed of UNIVAC was higher than ENIAC with one disadvantage of vacuum tubes
generating enormous amount of heat which made the mandatory requirement of a large good air
conditioning system.
Later in 1954, Univac II was developed. In 1962, the concept of virtual memory, a powerful feature
which shall be discussed in later sections, was introduced in mainframes making the system even
more powerful.
In 1964, the first third generation computer named as Burroughs B5000 came into market. This
mainframe system had various powerful specialized features like multiprogramming,
multiprocessing and virtual memory.Later on various improved versions of Burroughs series came into market with new features in each.
Among this the most notable one was B6700 which came in the year 1971 and this supported the
feature of dynamic linking of programs at runtime.
IBM was producing and releasing mainframes in the market at all periods from past till present with
the successive development of IBM Series starting with System/360.
One of the biggest factors associated with mainframes is its huge cost which made its usage only
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possible for big companies and corporate. There are still many technical terms one must get
familiarized with mainframe systems to understand about mainframe systems in depth.
Let us see some of the internal technical usage of mainframe system.
Mainframe Channel:
A mainframe channel connect to one or more controllers via either pairs of large "bus and tag"
cables or, fiber optic ESCON (Enterprise System CONnection) cables and FICON, which has the ability
controlling one or more devices. This is one of the important term in mainframe technology since it
has the ability of take care of huge input and output functions.
DASD:
DASD stands for Direct Access Storage Device. This indicates to any type of storage that was directly
(randomly) addressable.
LPAR:
LPAR stands for Logical Partition and is a powerful hardware or firmware feature implemented in all
mainframe systems. By this feature it is possible to create partitions and by which CPUs and I/O sub-
systems can be shared between logical partitions.
(Source: http://www.exforsys.com/)______________________________________________________________________________
UNIT 9
Artificial Intelligence
The branch ofcomputer science concerned with making computers behave like humans. The term
was coined in 1956 by John McCarthy at the Massachusetts Institute of Technology. Artificial
intelligence includes
o games playing: programming computers to play games such as chess and checkerso expert systems : programming computers to make decisions in real-life situations (for
example, some expert systems help doctors diagnose diseases based on symptoms)
o natural language: programming computers to understand natural human languageso neural networks : systems that simulate intelligence by attempting to reproduce the types
of physical connections that occur in animal brains
o robotics: programming computers to see and hearand react to other sensory stimuli
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Currently, no computers exhibit full artificial intelligence (that is, are able to simulate human
behavior). The greatest advances have occurred in the field of games playing. The best computer
chess programs are now capable of beating humans. In May, 1997, an IBM super-computer called
Deep Blue defeated world chess champion Gary Kasparov in a chess match.
In the area of robotics, computers are now widely used in assembly plants, but they are capable only
of very limited tasks. Robots have great difficulty identifying objects based on appearance or feel,and they still move and handle objects clumsily.
Natural-language processing offers the greatest potential rewards because it would allow people to
interact with computers without needing any specialized knowledge. You could simply walk up to a
computer and talk to it. Unfortunately, programming computers to understand natural languages
has proved to be more difficult than originally thought. Some rudimentary translation systems that
translate from one human language to another are in existence, but they are not nearly as good as
human translators. There are also voice recognition systems that can convert spoken sounds into
written words, but they do not understand what they are writing; they simply take dictation. Even
these systems are quite limited -- you must speak slowly and distinctly.
In the early 1980s, expert systems were believed to represent the future of artificial intelligence andof computers in general. To date, however, they have not lived up to expectations. Many expert
systems help human experts in such fields as medicine and engineering, but they are very expensive
to produce and are helpful only in special situations.
Today, the hottest area of artificial intelligence is neural networks, which are proving successful in a
number of disciplines such as voice recognition and natural-language processing.
There are several programming languages that are known as AI languages because they are used
almost exclusively for AI applications. The two most common are LISP and Prolog.
(Source: http://www.webopedia.com/)
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UNIT 10
Operating System
Computer Operating Systems
Operating system refers to the most important program that runs on a computer. Every general-
purpose computer must have an operating system to run other programs. Operating systems
perform basic tasks, such as recognizing input from the keyboard, sending output to the display
screen, keeping track of files and directories on the disk, and controlling peripheral devices such as
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disk drives and printers. The purpose of an operating system is to organize and control hardware and
software so that the device it lives in behaves in a flexible but predictable way.
For large systems, the operating system has even greater responsibilities and powers. It is like a
traffic cop it makes sure those different programs and users running at the same time do not
interfere with each other. The operating system is also responsible for security, ensuring that
unauthorized users do not access the system.
All desktop computers have operating systems. The most common are the Windows family of
operating systems developed by Microsoft, the Macintosh operating systems developed by Apple
and the UNIX family of operating systems (which have been developed by a whole history of
individuals, corporations and collaborators). There are hundreds of other operating systems
available for special-purpose applications, including specializations for mainframes, robotics,
manufacturing, real-time control systems and so on.
For a desktop computer user, this means you can add a new security update, system patch, new
application or even an entirely new operating system rather than junk your computer and start again
with a new one when you need to make a change. As long as you understand how an operating
system works and how to get at it, in many cases you can change some of the ways it behaves. Thesame thing goes for your phone, too.
How Operating Systems Work
When you turn on your computer, its nice to think that youre in control. Theres the trusty
computer mouse, which you can move anywhere on the screen, summoning up your music library or
Internet browser at the slightest whim. Although its easy to feel like a director in front of your
desktop or laptop, theres a lot going on inside, and the real man behind the curtain handling the
necessary tasks is the operating system.
As a user, you normally interact with the operating system through a set ofcommands. For example,
the DOS operating system contains commands such as COPY and RENAME for copying files andchanging the names of files, respectively. The commands are accepted and executed by a part of the
operating system called the command processor or command line interpreter. Graphical user
interfaces allow you to enter commands by pointing and clicking at objects that appear on the
screen.
Most desktop or laptop PCs come pre-loaded with Microsoft Windows. Macintosh computers come
pre-loaded with Mac OS X. Many corporate servers use the Linux or UNIX operating systems. The
operating system (OS) is the first thing loaded onto the computer without the operating system, a
computer is useless.
More recently, operating systems have started to pop up in smaller computers as well. If you like to
tinker with electronic devices, youre probably pleased that operating systems can now be found onmany of the devices we use every day, from cell phones to wireless access points. The computers
used in these little devices have gotten so powerful that they can now actually run an operating
system and applications. The computer in a typical modern cell phone is now more powerful than a
desktop computer from 20 years ago, so this progression makes sense and is a natural development.
When you turn on the power to a computer, the first program that runs is usually a set of
instructions kept in the computers read-only memory (ROM). This code examines the system
hardware to make sure everything is functioning properly. This power-on self test (POST) checks the
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CPU, memory, and basic input-output systems (BIOS) for errors and stores the result in a special
memory location. Once the POST has successfully completed, the software loaded in ROM
(sometimes called the BIOS or firmware) will begin to activate the computers disk drives. In most
modern computers, when the computer activates the hard disk drive, it finds the first piece of the
operating system: the bootstrap loader.
The bootstrap loader is a small program that has a single function: It loads the operating system intomemory and allows it to begin operation. In the most basic form, the bootstrap loader sets up the
small driver programs that interface with and control the various hardware subsystems of the
computer. It sets up the divisions of memory that hold the operating system, user information and
applications. It establishes the data structures that will hold the myriad signals, flags and
semaphores that are used to communicate within and between the subsystems and applications of
the computer. Then it turns control of the computer over to the operating system.
Operating systems provide a softwareplatform on top of which other programs, called application
programs, can run. The application programs must be written to run on top of a particular operating
system. Your choice of operating system, therefore, determines to a great extent the applications
you can run. For PCs, the most popular operating systems are DOS, OS/2, and Windows, but others
are available, such as Linux.
Types of Operating Systems
Within the broad family of operating systems, there are generally four types, categorized based on
the types of computers they control and the sort of applications they support. The categories are:
Real-time operating system (RTOS) Real-time operating systems are used to controlmachinery, scientific instruments and industrial systems. An RTOS typically has very little
user-interface capability, and no end-user utilities, since the system will be a sealed box
when delivered for use. A very important part of an RTOS is managing the resources of the
computer so that a particular operation executes in precisely the same amount of time,
every time it occurs. In a complex machine, having a part move more quickly just becausesystem resources are available may be just as catastrophic as having it not move at all
because the system is busy. Real-time responds to input instantly. General-purpose
operating systems, such as DOS and UNIX, are not real-time.
Single-user, single task As the name implies, this operating system is designed to managethe computer so that one user can effectively do one thing at a time. The Palm OS for Palm
handheld computers is a good example of a modern single-user, single-task operating
system.
Single-user, multi-tasking This is the type of operating system most people use on theirdesktop and laptop computers today. Multi-tasking allows more than one program to run
concurrently. Microsofts Windows and Apples MacOS platforms are both examples of
operating systems that will let a single user have several programs in operation at the same
time. For example, its entirely possible for a Windows user to be writing a note in a wordprocessor while downloading a file from the Internet while printing the text of an e-mail
message.
Multi-user Multi-user allows two or more users to run programs at the same time. Someoperating systems permit hundreds or even thousands of concurrent users. A multi-user
operating system allows many different users to take advantage of the computers resources
simultaneously. The operating system must make sure that the requirements of the various
users are balanced, and that each of the programs they are using has sufficient and separate
resources so that a problem with one user doesnt affect the entire community of users.
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UNIX, VMS and mainframe operating systems, such as MVS, are examples of multi-user
operating systems.
Other types:-. multiprocessing: Supports running a program on more than one CPU.
-. multithreading: Allows different parts of a single program to run concurrently.
Its important to differentiate between multi-user operating systems and single-user operating
systems that support networking. Windows 2000 and Novell Netware can each support hundreds or
thousands of networked users, but the operating systems themselves arent true multi-user
operating systems. The system administrator is the only user for Windows 2000 or Netware. The
network support and all of the remote user logins the network enables are, in the overall plan of the
operating system, a program being run by the administrative user.
Operating System Functions
At the simplest level, an operating system does two things:
1. It manages the hardware and software resources of the system. In a desktop computer,these resources include such things as the processor, memory, disk space and more (On a
cell phone, they include the keypad, the screen, the address book, the phone dialer, the
battery and the network connection).
2. It provides a stable, consistent way for applications to deal with the hardware withouthaving to know all the details of the hardware.
The first task, managing the hardware and software resources, is very important, as various
programs and input methods compete for the attention of the central processing unit (CPU) and
demand memory, storage and input/output (I/O) bandwidth for their own purposes. In this capacity,
the operating system plays the role of the good parent, making sure that each application gets the
necessary resources while playing nicely with all the other applications, as well as husbanding the
limited capacity of the system to the greatest good of all the users and applications.
The second task, providing a consistent application interface, is especially important if there is to be
more than one of a particular type of computer using the operating system, or if the hardware
making up the computer is ever open to change. A consistent application program interface (API)
allows a software developer to write an application on one computer and have a high level of
confidence that it will run on another computer of the same type, even if the amount of memory or
the quantity of storage is different on the two machines.
Even if a particular computer is unique, an operating system can ensure that applications continue to
run when hardware upgrades and updates occur. This is because the operating system not the
application is charged with managing the hardware and the distribution of its resources. One of
the challenges facing developers is keeping their operating systems flexible enough to run hardware
from the thousands of vendors manufacturing computer equipment. Todays systems can
accommodate thousands of different printers, disk drives and special peripherals in any possible
combination.
(Source: http://www.webopedia.com/;
http://computer.howstuffworks.com/operating-system.htm
by Curt Franklin and Dave Coustan)
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READING COMPREHENSION
Answer these questions
1. What does operating system (OS) refer to?2. What are some examples of OS?3. How does OS work? Make it brief by giving some steps.4. Name the types of OS and explain briefly.5. What are the functions of OS?
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