Computer System

​Block Diagram of Computer System

Central Processing Unit

• It is the electronic circuitry of a computer that carries out the actual processing and is usually referred to as the brain of the computer. It is also commonly called 'processor' also.

• Physically, a CPU can be placed on one or more microchips called integrated circuits (IC). The ICs comprise semiconductor materials.

• The CPU is given instructions and data through programs. The CPU then fetches the program and data from the memory and performs arithmetic and logical operations as per the given instructions and stores the result back to memory.

• The CPU has two main components — Arithmetic Logic Unit (ALU) and Control Unit (CU). ALU performs all the arithmetic and logic operations that need to be done as per the instruction in a program. CU controls sequential instruction execution, interprets instructions and guides data flow through the computer’s memory, ALU and input or output devices. CPU is also popularly known as microprocessor.

Some examples of

input devices include keyboard, mouse, scanner, touch

screen, etc.,

Specially designed

braille keyboards are also available to help the visually

impaired for entering data into a computer.

The devices through which control signals are sent

to a computer are termed as input devices. These

devices convert the input data into a digital form that is

acceptable by the computer system.

For example, monitor, projector,

headphone, speaker, printer, etc.

A braille display monitor is

useful for a visually challenged person to understand

the textual output generated by computers.

The device that receives data from a computer system

for display, physical production, etc., is called output

device. It converts digital information into humanunderstandable

form.