Generation of computers...............  

The term 'computer generation' is used in relation to the hardware of the computers.Each phase computer development is chractrerised by the type of switching circuits used in them.There are five generations of computers namely,first,second,third,fourth and fifth.
Computers which are used vacuum tubes are considered as first generation computers.They were very large in size and their programming was very difficult.The operating speed of first generation computers was very slow.These computer's consuption of power was high.ENIC,EDVAC,EDSAC,AND UNIVAC-I were some computers belonging of the first generation.Second generation computers used transistor,instead of vaccum tubes.these were highly reliable and cheaper than vaccum tubes Development of magnetic cores for storage was done in this period.Also second generation computers used high level languages,such as COBOL,FORTRAN etc.Operating systems also developed in this period.IBM_1401 and UNIVAC_1108 are examples of second generation computers.The third generation computers used 'Integrated Circuits' known as chips.These computers were highly reliable,cheaper and faster than second generation computers.Third generation computers used Small Scale Integrated circuits and Medium Scale Inegrated Circuits.Some examples of third generation cimputers are IBM-360 series,Honeywell-6000 series and ICL-1900 series.Fourth generation computers replaced SSI and MSI circuits by LSI and VLSI circuits.Fifth generation computers not yet come.