1] First Generation (1940-1956): Vaccum Tubes
Characteristics:
– The first generation computers were based on vaccum tubes.
– The first generation computers were very large require a lot of space and consume more electricity.
– Since, they were big, they were not portable.
– They lacked in versatility and speed.
– These machines were unreliable and prone to frequent hardware failure.
– These machines were programmed using machine language which was difficult to use.
Examples:- ENIAC, EDVAC, UNIVAC
2] Second Generation Computer (1956-1963): Transistors
Characteristics:
– These machines were based on transistor technology.
– These machines were smaller as compared to first generation computer.
– These were more portable and generated less amount of heat.
– These computers were programmed using assemble language.
– These computers were more reliable and less prone to hardware failure.
– The computational time of these computers was reduced to microsecond from millisecond.
Example: CDC, PDP
3] Third Generation Computers (1964-1970): Integrated Circuit (IC)
Characteristics
– These computers were based on IC technology.
– These computers were able to reduce computational time from microsecond to nanosecond.
– These computers consumed less power & generated less heat.
– These computers were smaller as compared to previous generation computer.
– The maintenance cost was low as there were less hardware failure.
– High level language were used from this generation.
Example: PDP, IBM 370/168
4] Fourth Generation Computers (1970-till date): Micro-Processor
Characteristics:
– Fourth generation computer are micro-processor based system.
– The size of fourth generation computer are relatively very small comparison to others hence they are easily portable.
– These machines generate negligible amount of heat.
– Hardware failure is negligible so minimum maintenance is required.
– GUI and pointing devices enable users to use and learn quickly.
– Interconnection of computers lead for better communication and resource sharing.
Example:- IBM 360, Macintosh
5] Fifth Generation Computers (Present and Beyond): Bio Chip
Characteristics:
– The fifth generation computer will be based on SLSI (Super Large Scale Integrated) chips.
– Fifth generation computers will be based on artificial intelligence (AI), human gesture and voice commanded.
– They will have large storage capacity and faster processing capacity.
– Parallel processing will be used for multiple access and interconnection work.
– Fifth Generation computers will simulate and reproduce human behavior, including thinking, speaking and reasoning.