Subject: Computer Science
Computer generations classification is mainly based on the basic devices used. Also, the considerations are the architecture, languages, modes of operation, etc. The function performed by the computer and the speed of their operations have been changing since the old days to the most modern computer. Based on the period of development and the features incorporated, the computers are classified into different generations- First generation to Fifth generation. This is called the computer generation.
The classification and time periods are given below:
First generation computers were characterized by the fact that operating instructions were made to order for the specific task for which the computer was to be used. It was operated on the ' Principle of Thermionic Emission".
In the first generation computer, vacuum tubes as CPU, magnetic drum for data storage , and machines languages were used for giving instruction.The computer of this generation was very large in size called room-sized computers.
The programming of first generation computers was done in machine languages (0s and 1s). Afterward, assembly languages were developed and used in first generation computer.
Features of first generation computers:
The example of first generation computers is ENIAC, UNIVAC,EDVAC, and EDSAC.
Second generation computer replaced machine language with assembly language, allowing abbreviated programming codes to replace long, difficult binary codes.
The transistor was developed in this generation. A transistor transfers electric signals across a resistor. A transistor was highly reliable compared to tubes.
The transistor was far more superior in performance on account of their miniature size, smaller power consumption, and heat production rate. The second generation computer used these semiconductor devices.
Some of its features are:
Transistors were an improvement over the vacuum tube, but they still generated a great heat, which damaged the computer's sensitive parts. The quartz eliminated this problem.
Transistors were replaced with an integrated circuit known popularly as chips. Scientist managed to fit many components on a single chip. As a result, the computer became ever smaller as more components were squeezed on the chip.
IC was first designed and fabricated by Jack S Kilby at Texas Instrument and by Robert S Noyce at Fairchild independently. IC is a circuit consisting of a large number of electronic components placed on a single silicon chip by a photo-lithographic process.
Magnetic disks began to replace magnetic tape for auxiliary and video display terminals were introduced for the output of data. Keyboards were used for the input of data. A new operating system was introduced for automatic processing and multi-programming.
These computers were highly reliable, relatively expensive and faster. High-level programming languages continued to be a developer. The example of third generation computers is IBM-360 series, ICL-900 series, and Honeywell 200 series.
Features of the third generation computers are:
4.) Fourth Generation Computer (1972 onward)
The invention of microprocessor chip marked the beginning of the fourth generation computers. Semiconductor memories replaced magnetic core memories. The invention of microprocessors led to the development of microcomputer or the personal computer.
The first microprocessor called Intel 4004 was developed by American Intel Corporation 1971.
This computer has faster generation language and application software for microcomputers became popular and allowed home and business users to adapt their computers for word processing, spreadsheet manipulating, file handing and graphics.
In this generation, the concept of computer networks and CD-ROMs came into existence.
Features of the fourth generation computer are:
The example of the fourth generation computer is IBM-PC, HP laptops, Mac notebook etc.
The aim is to bring machines with genuine IQ, the ability to reason logically and with real knowledge of the word. Thus, this computer will be totally different, totally novel and totally new than last four generations of computer.
Fifth generation computer was based on Artificial Intelligence (AI) and that is still developing process, but not yet a reality i.e this computer is incomplete. The scientists are working on it still.
These computers will be able to converse with people and will be able to mimic human sense, manual skills, and intelligence.
Features of the fifth generation computers are:
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