Computers very basics Part-2

Generations of Computers

1st Generation:

These computers were used in the period between 1951 and 1959. These computes were made of vacuum tubes.

These were very large in size but very slow in working.

2nd Generation:

These computers were used in the period between 1959 and 1963. Transsistors were used in the place of vacuum tubes.

These were much reliable and faster in speed and smaller in size when compare to the 1st generation computers.

3rd Generation:

These computers were used in the period between 1963 and 1975. Integrated circutis (I.C) were used in the place of Transistors. Integrated circutis means combination many transistors and an electronic circults in a single chip. These were much more reliable, faster in speed and were more capable of storing data, when compared to the 2nd generation computers.

4th Generation: These computers are in use since 1975. These are made of micro processors chips, which hold the entire control unit and arithmetic and logic uint.

Generation Period Component

1st Generation From 1951 to 1959 Vacuum Tubes

2nd Generation From 1959 to 1963 Transsistors

3rd Generation From 1963 to 1975 Integrated Circuit

4th Generation From 1975 onwards Micro processor

Parts o computers

The main parts of a computer are

Input device

Central processing unit

Output device

Input Unit

The keyboard is the main input device, through which the dta is put into computr for the computation. Other examples for the input devices are mouse, scannar and Joystick.

C.P.U.

C.P.U. Stands for central processing unit. It is the brain of a computer. It is also known as system unit. The system unit consists of memory unit, control unit and arithmetic and loic unit (A.L.U)

1. Memory unit: Memory is an important part of the C.P.U. when w feed the data into the computer, the C.P.U. first send it to the memeory unit, where it is stored.

2. Control Unit: This unit controls all the parts of the computer. It deals with th einput as per the instructions using the memory and the A.L.U. After the processing, it sends results back to the memory from where they will send the output device.

3.Arithmetic and logic unit: It is the part of CPU. it decodes program instructions, solves arithmetic problems and carries out tasks which need logic to arrive at an answer.

Out put unit

The information that comes out of he computer is called the output. Monitor and printer are teh examples fro the output device. Generally output is viewed on screen and printout is taken from printer.