Practical 1

1. Draw a block diagram of Computer and explain its basic parts.

Computer

A computer is an electronic device that performs certain mathematical and logical operations as per the instruction given by the user.

OR

A computer is an electronic device that can accept data, store data, process data as desired, retrieve the stored data as and when required and print the result in desired format.

 Block Diagram of Computer

The basic components are

Central Processing Unit (CPU) which consists of ALU and CU.

Input Device

Output Device

CPU (Central Processing Unit)

The central processing unit is sometime referred as the brain of computer. It is main part of computer system. All the operations within the system are processed and supervised by CPU. Thus CPU performs arithmetic and logical operations, controls the memory usage and sequence of operations. To perform all these operations CPU has three subunits. They are

• Arithmetic and logical Unit
• Control Unit
• Memory

Arithmetic and Logical Unit:

Actual execution takes place in ALU. It performs the arithmetic and logical operations.

• Integer Arithmetic operations: Addition, Subtraction, Multiplication and Division.
• Bit Wise logic operation: AND, NOT, OR, XOR etc.
• Bit shifting operations: shifting or rotating a word by a specified numbers of bits to the left or right. Shift can be interpreted as multiplication by 2 and division by 2.

 Control Unit:

The control Unit controls all the operations which take place internally within the CPU and all the operations related to input / output device. Control unit interpret the instructions or program instructions and generate control signals to ensure correct execution of the program. The control unit directs the overall functioning of computer.