Notes and Study Materials

Different Generations of computers:

The development of computers has followed different steps in the terminology used and these steps of technological differences are called as GENERATIONS in computer terminology. There are totally five generations of computers till today.

I. First Generation Computers (1950's)

These computers are used vacuum tubes (valves) as major electronic component the advantage of vacuum tubes technology is that it made the advent of Electronic digital computer vacuum tubes were only electronic devices available during those days which made computing possible.


Some of the computers of First Generation were:




It was the first electronic computer built in 1946 at University of Pennsylvania, USA by John Eckert and John Mauchy. It was named Electronic Numerical Integrator and Calculator (ENIAC). TheENIAC was 30_ 50 feet long, weighed 30 tons, contained 18,000 vacuum tubes, 70,000 registers, 10,000 capacitors and required 150,000 watts of electricity. Today your favorite computer is many times as powerful as ENIAC, still size is very small.




It stands for Electronic Discrete Variable Automatic Computer and was developed in 1950. The concept of storing data and instructions inside the computer was introduced here. This allowed much faster operation since the computer had rapid access to both data and instructions. The other advantages of storing instruction were that computer could do logical decision internally.




The limitations of the First Generations of computer are:


1. The operating speed was quite slow.

2. Power consumption was very high.

3. It required large space for installation.

4. The programming capability was quite low.


II. Second Generation Computers (1960's):


With the development of Transistors and their use in circuits, magnetic core for memory storage, the vacuum tubes are replaced by transistors to arrive at 2'nd generation of computers. The size of transistors is much smaller when compared to vacuum tubes, they consume less power, generated less heat and faster and reliable.




1.  Size of Computer has come down as well as power consumption.


2. The Cost of Computer reduced.


Some of the computers of the Second Generation were


IBM 1620: Its size was smaller as compared to First Generation computers and mostly used for scientific purpose.

IBM 1401: Its size was small to medium and used for business applications.

CDC 3600: Its size was large and is used for scientific purposes.


III. Third Generation Computers (1970's):


The development of silicon chips, the third generation of computers came into existence. These computers are used Integrated Circuits (IC's) of silicon chips, in the place of transistors. Each of these IC's consist of large number of chips in very small packages.




The size of computers, cost, heat generation and power consumption decreased to great extent, speed and reliability increased as compared to previous generation. These machines used IC's with large scale Integration (LSI).


IV. Fourth Generation (1980's)


The Computers belonging to these generations used Integrated circuits with Very Large Scale Integration (VLSI).




1. These computers have high processing powers, low maintenance, and high reliability and very low power consumption.

2. The size & cost of computers come down drastically


V.  Fifth Generation (Late 1990's):


These computers use optic fiber technology to handle Artificial Intelligence, expert systems, Robotics etc., these computers have very processing speeds and are more reliable.




You May Also Like

Characteristics of computers

Applications of Computers

Block Diagram of Computer

Different Input and Output Devices

Advantages of Computer Networks

Back To Fundamentals of Information Technology Questions