"An Introduction to History of Computers"

Depending on the technology or type of electronic components used, the history of automatic electronic computers can be classified  into five generations.

1^st Generation Computers :

In 1^st generation computers, electronic valves(Vacuum Valves) were used to construct electronic circuits. These large circuits required high consumption of energy and produced high tempreture and heat. the following characteristic were seen in these computer systems.

a)      High cost involvement.

b)      Space requirement was very high.

c)      Maintenance of these computers was very complicated.

d)      Only large research institutions could obtain.

e)      Less programming facilities were available.

2^nd Generation Computers :

In 2^nd Generation computers transistors (TRANsfers + reSISTORS) were used to construct electrtonic circuits. The characteristics of 2^nd generation computers are given below.

a)      Less cost involvement.

b)      Computers were smaller than 1^st generation computers.

c)      Less energy consumption.

d)      More programming facilities.

3^rd Generation Computers :

In 3^rd generation computers integrated circuits (IC’s / Silicon Chips) were used to circuits.

Because of this integration the size of large or mainframe computers could be reduced and this type of small-scale multi user systems is described as mini computer systems.

4^th Generation Computers :

Development of micro electronic technology produced integrated circuits with different levels of integration such as,

      SSIC   (Small Scale Integrated Circuits)

      MSIC  (Medium Scale Integrated Circuits)

      LSIC   (Large Scale Integrated Circuits)

      VLSIC ( Very Large Scale Integrated Circuits)

Generally CPU combination of a number of large electronic circuits together. But after the introduction of VLSI circuits this CPU was integrated and produced as a very small unit. This type of integrated CPU on a small silicon chip is called a MPU (Micro Processing Unit). Micro Computer or PC uses MPU as its CPU. With user friendly programming facilities these micro computers became very popular for business and other professional computer applications. Introduction to micro computers network (PC based multi-user system), portable computers such as LAPTOPS, NOTEBOOKS, PALMTOPS can be described as some other achievements in this generation.  

5^th Generation Computers :  

5^th generation computers can be describe as computers in the future, which use artificial intelligence or knowledge bases to facilities computer systems to think on their own.