Tuesday, March 17, 2009

Computer History

First Generation (1942-1955):
The beginning of the commercial computer age is from UNIVAC. It was developed by the Census Department of United States and developed by two scientists Mauchly and Eckert in1947. First generation computers were based on vacuum tube, which was a glass that controlled and amplified signals.
Advantages:
vacuum tubes were the only electronic components available during those days.vacuum tube technology made possible to make electronic digital computer.these computers could calculate data in millisecond.
Disadvantages:
These computers were very large in size.Consumed very large amount of energy.They got heated very soon due to many vacuum tubes.They were not reliable.Air conditioning was required.Constant maintenance was required.They was not portable.Commercial production was very costly.Commercial use was limited.They were very slow in speed.They used only machine language.They were not versatile.

Second Generation (1955-1964):
In the second generation computers transistors were used instead of vacuum tubes. Transistor is a small device that transfers electronic signals across a resistor.
Advantages:
Smaller in size as compared to first generation computer.They were more reliable.They were more energy-efficient.They were not heated because of less energy.Commercial use of wider.Portability was possible.their speed was much better.They could calculate data in microsecond.They used assembly language instead of assembly language.
Disadvantages:
Air conditoning was required.Constant maintenance required.Commercial production was difficult.They were used only for specific purposes.They were very costly.They were not versatile.

Third Generation (1964-1975):
In 1958 integrated circuit ( IC ) were developed. An IC combined three electronic components onto a small silicon disc. Scientists later manged to fit ever smaller as a result. Operating system was also produced at that time.
Advantages:
They were smaller in size was compared to previous generations.They were more reliable.They used less energy.They were very speedy.They could calculate data in neno-second.Maintenance was low.They were used for general purposes.Could be used for high level languages.They had storage.Better accuracy. They used, mouse, keyboard for input.
Disadvantages:
Air conditioning was requied.HIgh sophisticated technology required for manufacturing of IC.

Fourtth Generation (1975-present):
In this generation microprocessors were used. Micro processor is a small chip containing thousands of ICs on it. It greatly reduced the size of the computer
Advantages:
They were very small in size.They use less power.They generate less heat.It has a large fan for heat discharging.No air conditioning is required.They have best speed to read data.They are reliable and powerful.They are used for commercial production.Less need of repairing.They are among all generations.
Disadvantages:
High sophusticated technology required for manufacturing microprocessor.

Fifth Generation:
Scientists are working now 5th generation computer using recent. Computer can understand spoken words instruction. The ability to translate a foreign language is also moderately possible with fifth generation computers. Artificial intelligence is though to be used in this kind of computers. Japan is working in this direction by choosing Protocol language as its operating system.