IT102: ICT WORKSHOP PRACTICES Chapter 1: Introduction to Computer Hardware IT102: ICT WORKSHOP...

IT102: ICT WORKSHOP PRACTICES


Chapter 1: Introduction to ComputerHardware

Prepared By: Binal Patel 1 | P a g e


Introduction to Computer Hardware1.1 Definition of Computer

- A computer is an electronic device that can perform avariety of operations according to a set of instructionscalled program. It then displays or prints the result.

- The principle of INPUT-PROCESS-OUTPUT is applied to thecomputer. It is electronic device capable of solvingproblem or manipulating data by accepting data, performingprescribed operation (mathematical or logical) on the data& supplying the result of these operations as output.

OR- Computer is an electronic device which is capable of

receiving information (data) in a particular form and ofperforming a sequence of operations in accordance with apredetermined but variable set of procedural instructions(program) to produce a result in the form of information orsignals.

A computer generally means a programmable machine. The twoprincipal characteristics of a computer are: it responds toa specific set of instructions in a well-defined manner andit can execute a prerecorded list of instructions(a program).



A computer includes various devices:- Central Processing Unit (CPU)- Monitor- Keyboard and Mouse

The unique capabilities and characteristics of a computer:- Speed- Storage capacity- Accuracy- Reliability- Versatility- Diligence

Basic application of Computer:



1.2 Computer Hardware, Software and Firmware

Hardware :

- The physical components of computers are called hardwaresuch as input devices, output devices, processing devices,memory devices etc.It provides shape and size and supportsoftware for proper functioning. Registers, CPU, Hard Disk,printers, and Mouse etc which are touchable, visible,replaceable electromechanical and electronic part ofcomputer and hardware.



Hardware does all operations:- - Accepting & Storing data- Performing calculations - Displaying or Printing Results.

Parts of computer:- The following illustration shows the most common hardware

in a desktop computer system. Your system might look alittle different, but it probably has most of these parts.A laptop computer has similar parts but combines them intoa single, notebook-sized package.

Desktop computer system

- Let's take a look at each of these parts.

Monitor- A monitor displays information in visual form, using text

and graphics. The portion of the monitor that displays the



information is called the screen. Like a television screen,a computer screen can show still or moving pictures.

- There are two basic types of monitors: CRT (cathode raytube) monitors and the newer LCD (liquid crystal display)monitors. Both types produce sharp images, but LCD monitorshave the advantage of being much thinner and lighter.

LCD monitor (left); CRT monitor (right) Modem

- To connect your computer to the Internet, you need a modem.A modem is a device that sends and receives computerinformation over a telephone line or high-speed cable.Modems are sometimes built into the system unit, buthigher-speed modems are usually separate components.

Cable modem System unit

- The system unit is the core of a computer system. Usuallyit's a rectangular box placed on or underneath your desk.Inside this box are many electronic components that process



information. The most important of these components isthe central processing unit (CPU), or microprocessor, whichacts as the "brain" of your computer. Another componentis random access memory (RAM), which temporarily storesinformation that the CPU uses while the computer is on. Theinformation stored in RAM is erased when the computer isturned off.

- Almost every other part of your computer connects to thesystem unit using cables. The cables plug intospecific ports(openings), typically on the back of thesystem unit. Hardware that is not part of the system unitis sometimes called aperipheral device or device.

System unit Mouse

- A mouse is a small device used to point to and select itemson your computer screen. Although mice come in many shapes,the typical mouse does look a bit like an actual mouse.It's small, oblong, and connected to the system unit by along wire that resembles a tail. Some newer mice arewireless.



Mouse- A mouse usually has two buttons: A primary button (usually

the left button) and a secondary button. Many mice alsohave a wheel between the two buttons, which allows you toscroll smoothly through screens of information.

Mouse pointers- When you move the mouse with your hand, a pointer on your

screen moves in the same direction. (The pointer'sappearance might change depending on where it's positionedon your screen.) When you want to select an item, you pointto the item and then click (press and release) the primarybutton. Pointing and clicking with your mouse is the mainway to interact with your computer. For more information,see Using your mouse.

Speakers- Speakers are used to play sound. They can be built into the

system unit or connected with cables. Speakers allow you tolisten to music and hear sound effects from your computer.

Computer speakers Printer



- A printer transfers data from a computer onto paper. Youdon't need a printer to use your computer, but having oneallows you to print e-mail, cards, invitations,announcements, and other material. Many people also likebeing able to print their own photos at home.

- The two main types of printers are inkjetprinters and laser printers. Inkjet printers are the mostpopular printers for the home. They can print in black andwhite or in full color and can produce high-qualityphotographs when used with special paper. Laser printersare faster and generally better able to handle heavy use.

Inkjet printer (left); laser printer (right)

Keyboard- A keyboard is used mainly for typing text into your

computer. Like the keyboard on a typewriter, it has keysfor letters and numbers, but it also has special keys:

- The function keys, found on the top row, perform differentfunctions depending on where they are used.

- The numeric keypad, located on the right side of mostkeyboards, allows you to enter numbers quickly.

- The navigation keys, such as the arrow keys, allow you tomove your position within a document or webpage.



Keyboard- You can also use your keyboard to perform many of the same

tasks you can perform with a mouse.

Storage- Your computer has one or more disk drives—devices that

store information on a metal or plastic disk. The diskpreserves the information even when your computer is turnedoff.

Hard disk drive- Your computer's hard disk drive stores information on

a hard disk—a rigid platter or stack of platters with amagnetic surface. Because hard disks can hold massiveamounts of information, they usually serve as yourcomputer's primary means of storage, holding almost all ofyour programs and files. The hard disk drive is normallylocated inside the system unit.



Hard disk drive CD and DVD drives

- Nearly all computers today come equipped with a CD or DVDdrive, usually located on the front of the system unit. CDdrives use lasers to read (retrieve) data from a CD; manyCD drives can also write (record) data onto CDs. If youhave a recordable disk drive, you can store copies of yourfiles on blank CDs. You can also use a CD drive to playmusic CDs on your computer.

CD

- DVD drives can do everything that CD drives can, plus readDVDs. If you have a DVD drive, you can watch movies on yourcomputer. Many DVD drives can record data onto blank DVDs.

- If you have a recordable CD or DVD drive, periodically backup (copy) your important files to CDs or DVDs. That way, ifyour hard disk ever fails, you won't lose your data.

Floppy disk drive- Floppy disk drives store information on floppy disks, also

called floppies or diskettes. Compared to CDs and DVDs,floppy disks can store only a small amount of data. Theyalso retrieve information more slowly and are more prone todamage. For these reasons, floppy disk drives are less



popular than they used to be, although some computers stillinclude them.

Floppy disk- Why these disks are called "floppy" disks? The outside is

made of hard plastic, but that's just the sleeve. The diskinside is made of a thin, flexible vinyl material.

Software:

- Software is the collection of program and other associateddocuments that helps to control, manage and integrate thecomponents of computer system to accomplish a specifictask. It is a non-touchable, non viable set of instructionscoded in computer languages. It is a vital part ofcomputer, without it computer is nothing.

- Examples are operating system, compiler and interpreter,application software etc.

OR- Software is a collection of instructions that enable the

user to interact with a computer or have it performspecific tasks for them. Without software, computers wouldbe useless.

- For example, without your Internet browser software youwould be unable to surf the Internet or read this page andwithout a software operating system the browser would notbe able to run on your computer. In the picture isMicrosoft Excel, an example of a software program.



Firmware:

- Firmware is a pre written program that is stored in ROM. Itconfigures the computer and not easily modified by users.The instructions coded in BIOS( Basic Input Output Service)are example of Firmware. Firmware ROM contains loaderprogram to load a program into memory.

- Data stored in a computer or other hardware device read-only memory (ROM) or elsewhere in the circuitry thatprovides instruction on how that device should operate.Unlike normal software, firmware cannot be changed ordeleted by an end-user without the aid of special programsand remains on that device regardless if it's on or off.

- Firmware refers to the applications and operating systemthat control how a cell phone or smartphone operates. It iscalled firmware rather than software to highlight that itis very closely tied to the particular hardware componentsof a device. Firmware is generally flashed into a phone'sROM rather than simply being loaded into normal phonestorage, where it could more easily be erased and lost inthe event of a crash. Firmware updates are sometimesprovided by a company as a way to fix bugs or introduce newfunctionality.

- Firmware is programming that's written to the read-onlymemory (ROM) of a computing device. Firmware, which isadded at the time of manufacturing, is used to run userprograms on the device.

- Software (programs or data) that has been writtenonto read-only memory (ROM). Firmware is a combination of



software and hardware. ROMs, PROMs and EPROMs that havedata or programs recorded on them are firmware.

1.3 History of ComputerAbacus: The first year manual calculating device.

Analytical Engine: It was invented by Charles Babbage to doarithmetic calculations.

Census Machine: A punched card device developed by Dr.Herman Hollerith.

Harvard Mark: Developed by Howard University. This was thefirst machine ever to execute pre-programmed instructionswithout manual interface.

ENIAC: Electronic Numeric Integrator And calculator. Thefirst ever, all electronic computer

Generation of Computers:

First (1940-1956): Used Vacuum Tubes. It was very large.Generated immense heat.Very expensive.

Second (1956-1963): Used Transistors.Continued to be largeand expensive.

Third (1964-1975): Used Integrated Circuits (IC’s).Significant reduction in size and cost.

Fourth (1975-1989): Uses very large scale Integration(VLSI). Desktop computers would

not have been possible without VLSI.It used Microprocessorminimizing the size of PC.



Fifth (In progress): will provide us with ArtificialIntelligence. Also called knowledge

Information processing Systems.

1.4 Classification of Computer

We can classify the computer according to the following three criteria:

1) Based on operating principles

2) Based on applications



3) Based on size and capability

1.Based on operating principles:

Analog computers: represent data in the form of continuous

electrical signals having a specific magnitude.

- Analog computers that are normally used in the process

industry or in measuring instruments can directly measure

physical parameters- voltage, current, weight, Pressure,

Temperature etc...

- The analog computers do not operate directly on numbers and

these computers are used for scientific engineering

application.

Digital computers: store and process data in the digital form.

- Digital computers operate directly on number expressed in binary numbering system.

- They can:

• Perform complex and repetitive calculations accurately.

• Store large amount of data.

• Provide information in textual and graphical manner.

- PC is a digital computer. The Computers used in offices and homes are generally Digital.



Hybrid computers (Digital + Analog): a combination of analog

computer and digital computer because it encompasses the best

features of both.

2.Based on applications

General purpose computers: can work in all environments.

Special purpose computers: can perform only a specified task.

3.Based on size and capability

Microcomputers: Designed to be used by individuals.

- A microcomputer is the smallest general purpose processing

system that can execute program instructions to perform a

variety of tasks. They are classified as personal computers

and Home computers.

Mini Computers: Can handle more data and more input and outputthan micro computers.

- A minicomputer may be defined as a small general purpose

computer that is capable of handling large amount of data

from multiple users working simultaneously.

Mainframe Computers: A very large computer.

- A computer that is more powerful than a mini and mainframe

computer. All high level programming languages can be used

on available for mainframes and their operating system

programs offer very high level of sophistication.



Super Computers: The fastest type of computer that can perform

complex operations at a very high speed.

- The calculations needed in some scientific research and

development area can not do without supercomputers. These

computers are used in energy sector space exploration,

medicine, industry weather forecasting and other critical

areas.

- In India, centre for development of advance computing ( C-

DAC), Pune has developed the supercomputer “PARAM”.

1.5 Basic parts of Digital Computer

- The following illustration shows the most common parts ofDigital Computer system. Personal Computer is a digitalcomputer. The Computers used in offices and homes aregenerally digital.



Parts of Digital Computer:

- Monitor- Modem- System Unit- Mouse- Speaker- Printer- Keyboard- Hard disk drive- CD and DVD drive- Floppy disk drive

Classification of Digital computer:

- Desktop- Workstation



- Notebook- Tablet PC- Handheld Computer- Smart Phone

1.6 General Faults of Computer System

Missing DLL File

- Dynamic-Link Library (DLL) files house information for your

operating system on how to perform certain functions.

Occasionally, your computer loses DLL files or something

damages them. When your PC can't read the particular DLL

file, it doesn't know how to respond in certain situations.

You may have a missing or corrupt DLL file if you receive an

error message every time you perform a certain function,

such as saving. If your computer problems are stemming from

missing and damaged DLL files, you can restore them by

downloading them back onto your PC.

Applications That Won't Install

- If you're having trouble with an application not installing,

it may be because your computer doesn't have enough hard

drive space. If this is the case, you need to free up some



space. This is one of the computer problems that's, well,

least problematic. You can free up some hard drive space by

getting rid of files and folders you don't need. These may

be temporary files, duplicate files or data for software

you've uninstalled.

Applications Run Slowly

- There are several reasons software might be running at

turtle speed. You may have computer problems that involve

your operating system or an application, your operating

system might be missing updates or your computer doesn't

have enough hard drive space. If you don't have enough hard

drive space, you can scan, clean and optimize your hard

drive.

Abnormal Applications Behavior

- Computer problems that involve applications acting strangely

oftentimes leave you wondering what has happened. Your

application has been working just fine, but now, seemingly

without reason, it is doing something strange.

- For instance, your Word document will no longer show the top

margin of your document. It still says it's there, and when

you print it, there's not a problem. You just can't see it

on your monitor. If this is happening, you may want to

restart your computer. Conducting an internet search for the



type of problem you're experiencing or consulting your user

manual may help you as well.

Blue Screen of Death (BSoD)

- Many people think of blue as a calming color; however, when

it comes up on your computer screen with a bunch of white

text, it probably has the opposite effect. The blue screen

of death (BSoD or STOP Error) may appear to be one of the

scariest computer problems you'll come across. However, all

your computer may need is for you to reboot it. This STOP

error appears on your screen for a variety of reasons:

failing hardware, damaged software, corrupt DLL files,

problems with drivers and more. The remedy for a blue screen

of death depends on the original problem. The screen

provides you with codes that can help you identify and fix

your computer problems.

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Question Bank:

1. What is computer? Write down the basic applications of

computer.

2. Briefly explain hardware, Software and Firmware.



3. Write Short Notes on Hard disk drive, CD and DVD drive,

Floppy disk drive.

4. Explain History of Computer.

5. Write down all generation of computers.

6. Explain classification of computers.

7. Explain all basic parts of digital Computer.

8. Write down the general faults of computer system.


IT102: ICT WORKSHOP PRACTICES Chapter 1: Introduction to Computer Hardware IT102: ICT WORKSHOP...

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