Generation of Computer and Their Features

GENERATIONS OF COMPUTERS

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:

1. First Generation Computer (1945-1955)
2. Second Generation Computer (1957-1963)
3. Third Generation Computer (1964-1971)
4. Fourth Generation Computer (1972 onward)
5. Fifth Generation Computer (Present and future)

1.) First Generation Computer (1945-1955)

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:

• Technology used: vacuum tube
• Machines languages were used to instruct the computer.
• Magnetic core memory was used as primary memory.
• Electrostatic tubes, Parer tape, punch card, magnetic tape
• Punched card, printing devices were used for input/output operations and store the result.
• It occupies very large space, slow processing, inefficient and unreliable due to low accuracy.
• Power consumption was very high and it generated much heat.
• It could only perform straight forward simple numerical calculation.
• Computer used to be much expensive.

The example of first generation computers is ENIAC, UNIVAC,EDVAC, and EDSAC.

2.) Second Generation Computer (1957-1963)

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:

• Technology used: Transistor
• Operating speed was in terms of a microsecond.
• Assembly language and machines independent language such as COBOL (Common Business Oriented Language) and FORTRAN (Formula Translation) were introduced the size of the computer.
• Magnetic core memory was used as primary memory.
• Magnetic drum and magnetic tape were used as secondary memory.
• Power required to operate them was low.
• It could perform scientific calculation such as solving differential equations.
• Storage capacity and use of computers are increased.

3.) Third Generation Computer (1964-1971)

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:

• The technology used: IC (Integrated Circuit).
• Transistors were replaced by IC in their electronic circuitry.
• High-level languages like FORTAN , BASIC and other are used to develop programs.
• Semiconductor memory like RAM and ROM were used as primary memory.
• Monitor and keyboard were introduced for data input and output respectively.
• Multiprogramming facility was developed.
• The computer was used in census calculation, military, banks and industries.
• Size, cost, power requirement and heat generation decreased.
• Processing speed and storage capacity used of computer increased.

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:

• Technology in use: VLSI is introduced and used Microprocessor-based technology.
• Problem-oriented fourth generation language (4GL) is used to develop the program.
• Semiconductor like RAM, ROM and cache memory is used as a primary memory.
• Magnetic disks like hard disk, optical disk (CD,DVD), Blue-ray disk, flashes memory (memory chip, pen drive) are used as secondary memory.
• E-mail, Internet and mobile communication are developed.
• Advanced, user-friendly, web page software are developed.
• Size, cost, power requirement, heat generation decreased compared to the previous generation.
• Operating speed, storage capacity ,use of computer increased compared to the previous generation

The example of the fourth generation computer is IBM-PC, HP laptops, Mac notebook etc.

5.) Fifth Generation Computer (Present and future)

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:

• Technology to be used: These machines will incorporate Bio-chip and VVLSI (Very Very Large Scale Integration) or Ultra-Large Scale Integration (ULSI)
• The computer will have Artificial Intelligence (AI).
• Natural language will be used to develop programs.
• The computer will have parallel processing in full fledge.
• The operating speed will be in terms of LIPS(Logical Inference per Second)
• These aim is to solve highly complex problems, which require great intelligence and expertise when solved by people.
• Quantum computation, molecular and nanotechnology will be used completely.

Bibliography

Shrestha, R. P., & Manandhar, s. (2014). Computer Essential. Kathmandu: Ashmita publication.

Gurung, Juddha Bahadur et.al.,Computer Science-XI, Bhundipuran Prakashan,Ktm