Chapter Computer and its components

COMPUTERS AND ITS COMPONENTS

COMPUTER-MORE THAN A CALCULATING DEVICE

Computer is not mere a calculating device.It is a machine that can perform both arithmetic and non-arithmetic operations like copy, move select, compare etc.It works on alphabets, represents symbols and ideas as per the requirements of the user.
You can say, a computer is a machine which accepts data , process ita and produces results.Computer is also known as data processing machine.
Computer can do many things for user in exactily the way user wants.The only thing it requires is the correct input and logic.

THE WORK OF A COMPUTER

We can classify the work of computers according to its functions as given below:
1. Storing data and informations.
2. Calculating numbers.
3. Making decisions.

Storing data and information

As we store things in almirah and keep informations in diary for further use, in the same way computers keeps informations in its storage space for further use .Computer has a vast capacity to store information.The capacity is known as its memory.

CALCULATING NUMBERS

Computer can perform a large numbers of calculations in a fraction of seconds.It can perform all the four basic arithmetic operations i.e. addition, subtraction, multiplication and division as well as scientific operations.

MAKING DECISIONS

Computer can’t take decisions of its own.It take decisions as per the instructions given by the user.Suppose there are hundred students appeared in an examination and we have to find out the name of the students who have secured more than 60% marks.We developed this logic on computer and computer gives the result within few seconds.

COMPONENTS OF A COMPUTER

Following are the basic components of a computer:

KEYBOARD

A keyboard is the most important part of a computer.It is an input device which is used to input data and instructions into the computer.It’s keys look like a typewriter. It has some extra keys to carry out some different tasks.

SYSTEM UNITS

All operation are carried out in the system unit.It also follows the instructions given by the user.
All mathematical, logical and comparative analyses are done by this unit.
It has three components :

1.RAM (Random Access Memory)
2.C.P.U (Central Processing Unit)
3.Disk Drives

RANDOM ACCESS MEMORY (RAM)

Random Access Memory is used to store data and information temporarily.It is volatile memory.It means when a computer is switched off, it losses all its data and information started in RAM.It is also called read/write memory.

Central Processing Unit (CPU)

Central processing unit is the brain of computer.It controls all the parts of a computer.It takes data and information and process them as per the instruction given by the user.It is divided into three parts

1. MEMORY
2. ARITHMETICAL AND LOGICAL UNIT (ALU)
3. CONTROL UNIT (CU)

DISK DRIVES

Disk Drives is a part of computer to insert disk into the system unit.Disks are used to store data and information permanently.Hard disk is fixed into its drive while CD-ROM and floppy disk are insertable.

Three types of disks are used;
1.Hard disk
2.CD-ROM
3.Floppy disk

MONITOR

It looks like a television.This is an input/output device.It is used to display the processed data.It is also used like a notepad where we can see our writings and can remove the mistakes before it is processed by the CPU.

Types of monitor

Mainly two types of monitor are in use:
1. Monochrome Monitor
2. Colour Monitor

MONOCHROME MONITOR

This is also called black and white monitor.It can display objects in single colour.

COLOUR MONITOR

This monitor can display objects in several or single colour. Today there are monitors available which can show the figure, drawing or pictures in true colour.