Block Diagram of a Digital Computer
Let’s learn about the block diagram of a computer in this tutorial. The computer block diagram shows the primary components of the computer system.
The major components of a computer are as follows:
- CPU(Central Processing Unit)
- Input devices
- Output devices
Let’s discuss each major component in the block diagram of the computer system.
CPU stands for Central Processing Unit. It acts like the brain of the computer. The primary function of a CPU is to execute programs. Besides this, it also controls the operation of IO( Input-Output) devices and memory.
In small computers, a microprocessor chip acts as a CPU. The CPU contains the following major sub-components:
- Control Unit (CU)
- Arithmetic and Logic Unit (ALU)
- Registers (General & Special purpose)
Control Unit is responsible for coordinating various computer operations. It generates the timing and control signals that are necessary to execute the instructions. It also determines the sequence in which computer programs and instructions are executed.
Arithmetic & Logical Unit
The processing of the data and instructions is performed by the Arithmetic & Logical Unit. The ALU is used to perform arithmetic operations such as Addition, Subtraction, Multiplication, and Division. It can also perform logic operations such as AND, OR, NOT, EXCLUSIVE OR.
Registers are used to store the temporary results and data while performing the operations.
The main purpose of memory is to store information. Two types of memories are as follows:
- Main memory/ Primary memory
- Secondary memory/Auxiliary memory
The Main memory is volatile memory. The information stored in the main memory will be lost when the computer is shut down. On the other hand, the information stored on the Auxiliary memory like a hard disk is permanent. To improve the performance of the computer other memories like cache memory, virtual memory, etc are also used.
Input devices are used to enter information into the computer. An input device converts input information into a suitable binary form acceptable to a computer. The standard input device used on most computers is the keyboard. Examples of input devices are as follows:
- Light pen
- Touch screen
Output devices receive results and other information from the computer and display them to the computer users. The computer usually sends the information in the form of binary coded representation. Then output device converts it into user-understandable form and provides the output to the users. The standard output device used on most computers is the computer monitor.
Examples of output devices are as follows: