Generations of computers-notes

Generations of computers

Hello friends, in this article I am going to provide explanation on various generations of computers and their features which is very important from exam point of view.

So let’s start it.

How many generations of computer are there ?

Generations of computers were made based on the technological advancement, size, power of the computer etc. Computer generations are classified into five categories such as

i. First generation

ii. Second generation

iii. Third generation

iv. fourth generation

v. Fifth generation

Each of the successor generation was more advanced in terms of technological advancement than its predecessor generation of computers. let us discuss one by one.

First generation computers

Following are the characteristics of first generation computers

• The size of the computers were very large in size. It occupied a lot of space.
• Vacuum Tubes were used in computers.
• It produced a lot of heat resulting in frequent breakdown.
• The programs or instructions given to the computers were in machine language.
• Punched cards were used as input devices.
• Magnetic tapes and magnetic drums were used as secondary memory.
• Computer was accessible to only one programmer at a time.

Examples of first generation computers

• ABC
• ENIAC
• Von Neuuman machine
• EDVAC
• UNIVAC

Let’s discuss these computers in detail.

ABC

• ABC stands for Atanasoff Berry Computer.
• It was developed by Dr. John Vincent Atanasoff, a professor of Physics and Mathematics in 1937.
• This was the first electronical special purpose computer used to solve simultaneous equtions.

ENIAC

• ENIAC stands for Electronic Numerical Integrator and Calculator.
• It was developed by John Mauchly and J.Presper Eckert of the University of Pennsylvania to calculate figures for thousands of gunnery tables required by the U.S.Army.
• It could perform 500 multiplications per minute.
• it used thousands of Vacuum Tubes.
• It occupied a number of rooms.
• External plugboards or switches were used for giving instructions to the computer.
• It was used for World War II

Von Neuuman Architecture

• Von Neuuman Architecture was designed in 1945.
• Neuuman introduced the concept of prestored instructions as programs and binary numbering system instead of decimal system.
• It was based on stored program concept i.e. the program and data were stored in same memory location for execution.

EDVAC

• EDVAC stands for Electronic Discrete Variable Automatic Computer.
• It was designed by J.Presper Eckert and Mauchly at the University of Pennsylvania in 1949.
• Unlike its predecessor ENIAC , EDVAC was a binary computer.
• It was the first stored program electronic computer.

UNIVAC

• UNIVAC stands for Universal Automatic Computer.
• It was designed by J.Presper Eckert and Mauchly at the University of Pennsylvania in 1951 for use by the US CEnsus Bureau.
• It was the first general purpose electronic digital computer.
• It was an updated version of ENIAC.

Second generation computers

Second generation computers were technologically more advanced than the first generation computers.

Some of the features of second generation computers were,

• Transistor was used instead of Vacuum Tubes in computers.
• The computers were were smaller in size as compared to first generation computers.
• Use of transistors increased the operating speed and storage of computers.
• The operating cost of the computers reduced.
• Because of use of transistors less heat were generated resulting in fewer breakdowns in computers.
• The computers were reliable and faster than first generation computers.
• A language was developed for writing programs which consists of alphabets and numbers called as Assembly language but it was still difficult to write and understand.This brought about the development of high level language. This language was made from English words. The program were easier to write and understand.

Examples of second generation computers

The various computers developed during this period were

i. IBM 1400

ii. IBM 7040,

iii. CDC 3600,

iv. GE 635

v. B300 etc.

Third generation computers

Following are the characteristics of third generation computers

• The third generation computers are characterised by a new hardware technology that is Integrated Circuit. It was a thin chip made of silicon in which many transistors were packed.
• Because of the use of Integrated Circuit , the computers became more smaller, more reliable and more faster.
• It resulted in reduction in cost of the computers
• The computers in this generation used to consume less electricity.
• Semi conductor memories were used as main memory replacing earlier technology.
• Certain new techniques were introduced to increase the speed of program execution. These techniques were pipelining and multiprocessing.

Examples of third generation computers

The various computers developed in this generation are

i. IBM 360,

ii. Honeywell 200,

iii. B2000,

iv. ICL 1900 etc.

Fourth generation computers

Following are the features of fourth generation computers

• Fourth generation computers are characterised by LSI i.e. Large Scale Integartion and VLSI i.e. Very large Scale Integration. In this technology thousands of transistors could be packed in a single chip making the computers more faster.
• The computers became more lighter and thiner.
• The cost of the computers reduced.
• The computers used to consume less electricity.
• The computers used to produce less heat so there was no cooling requirement.
• The microprocessor were developed in this generation of computers
• Sharing of resources were done using various networks
• Many operating systems were developed like MS DOS, UNIX, Windows, Macintosh etc.

Examples of fourth generation computers

The various computers developed in this generation of computers are

i. IBM 370,

ii. Honeywell 6080,

iii. B6500, Apple,

iv. CRAY XMP,

v. VAX 9000 etc.

Fifth generation computers

Following are the characteristics of fifth generation computers

• Fifth generation computers are based on a new hardware technologyi.e. ULSI (Ultra Large Scale Integration). In ULSI millions of components can be stored in a single chip.
• Fifth generation computers are based on parallel processing in which several instructions can be executed parallely resulting in faster execution.
• The new software technology used in fifth generation computers is Artificial Intelligence which includes areas like Expert system, Speech recognition and Voice recognition etc.
• In fifth generation computers RAM, ROM are used as primary storage.
• HDD & SDD are used as secondary storage.
• Various high level languages were developed in this generation of computers like C, C++, Java, Python .Net etc.

Examples of fifth generation computers

Fifth generation computers are

i. Desktop,

ii. Laptop,

iii. Notebook,

iv. Palmtop etc. that we are using today.

Friends, let’s summarise the generations of computer in the following table

Generations	Periods	Hardware Technology used	Examples
First Generations	1940s-1950s	Vacuum Tubes	ABC ENIAC Von Neuuman machine EDVAC UNIVAC etc.
Second Generations	1950s-1960s	Transistors	IBM 1400 IBM 7040, CDC 3600, GE 635 B300 etc.
Third Generations	1960s-1970s	Integrated Circuits	IBM 360, Honeywell 200, B2000, ICL 1900 etc.
Fourth Generations	1970s-1980s	Microprocessors	IBM 370, Honeywell 6080, B6500, Apple, CRAY XMP, VAX 9000 etc.
Fifth Generations	1980s-till date	Artificial Intelligence	Desktop computer, Laptop, Notebook, Palmtop etc.

Conclusion

I hope, after reading the above article on generations of computer you must have a clear concept on various generations of computer.

If you are interested in reading multiple choice questions on generations of computers do visit the link below

MCQs on generations of computers

If you have any question or doubt regarding this you can ask me in the comment section given below or email me at [email protected]

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