Page 21 - DCAP101_BASIC_COMPUTER_SKILLS

Basic Computer Skills

Notes 1.4 Block Diagram of Computer

The basic components of a computer are:
• Input Unit
• Output Unit
• Memory/Storage Unit

• Arithmetic Logic Unit
• Control Unit
• Central Processing Unit
These are shown in Figure 1.2.

Figure 1.2: Block Diagram of Computer

Input Processing Output

Input Unit Storage Output unit

Control Unit

ALU

A computer can process data, pictures, sound and graphics. They can solve highly complicated
problems quickly and accurately.
1.4.1 Input Unit

Computers need to receive data and instruction in order to solve any problem. Therefore,
we need to input the data and instructions into the computers. The input unit consists of one
or more input devices. Keyboard is the one of the most commonly used input devices. Other
commonly used input devices are the mouse, floppy disk drive, magnetic tape, etc. All the
input devices perform the following functions:
• Accept the data and instructions from the outside world.
• Convert it to a form that the computer can understand.
• Supply the converted data to the computer system for further processing.

1.4.2 Storage Unit
The storage unit of the computer holds data and instructions that are entered through the
input unit, before they are processed. It preserves the intermediate and final results before
these are sent to the output devices. It also saves the data for the later use. The various
storage devices of a computer system are divided into two categories:

14 LOVELY PROFESSIONAL UNIVERSITY