Generation Of Computers

First Generation of computers (1942 to 1954)
The first generation of computers was introduced in the year 1942. The computers in this generation were very huge in size and generated a lot of heat and noise. They used thousands of Vacuum tubes (valves) as the main electronic component. Punched cards were used as Secondary storage device. It used Machine Level Language for operating.

Second Generation (1955 to 1964)
The Second generation of the computers started from the year 1955 by the use of Transistors as main electronic component. By the replacement of 1000s of vacuum tubes by the transistors the size of the computers was decreased. They were more reliable and faster. Magnetic core memory as main memory and the magnetic tape as the secondary memory was used in this generation. High level languages were introduced for programming.

Third Generation (1964 to 1974)
The IC (Integrated circuits) chips used in this generation made the computers much faster reliable and portable. The desktop computers were introduced for the first time. Semi-conductor memory as primary and the Magnetic disk as the secondary memory were used in these computers. Use of large volume of High level languages made the computer more user friendly. Speed of the computers was measured in nanoseconds.

Fourth Generation (1975 to 1990)
The introduction of Microprocessors brought out a great revolution in the field of computer. The main development in the computers took place in this generation. The computers were highly accurate and fully reliable with great speed. Micro computers like desktop, laptop, palmtop and even smaller computers were developed in this generation. Multi processing and multiprogramming was made possible. Introduction of 4GL and AI in software to some extent were some major achievements of this Generation. Faster I\O Devices and advances and portable memory devices were also introduced.

Fifth Generation (1990 up to now)
Though the fifth generation computers have not yet come into use, the generation is said to be started from the year 1990 with the development of the Bio-chips. The computer is said to have artificial Intelligence and is supposed to use different intelligent programs. It can work with different Natural Languages like Japanese, French, English etc. The use of GaAs (Gallium Arsenide) makes the computer much faster than it ever used to be. It uses Prolog (Programming Logic) as the Operating System.

Types of Computer
The classification of computers can be studied from different vantage points. Firstly the computers are categorized into different groups and then they are further divided into different types. The following Figure illustrates the types of the computers.