Generations of Computer

GENERATIONS:

The development of electronic computers is classified in five generations. During each generation the new technologies were used as the performance and application of computer were increased. Characteristics that distinguish generations are circuit elements, secondary storage media programming language primary memory and operating system.

THE FIRST GENERATION:

Main features /Characteristics

Major innovation         Vaccum tubes used as basic electronic component.  

Main memory              Magnetic drums

External Storage         Punched card

Input/ Output              Punched cards and paper

Language                    Machine language

Operating System       Human operation to set switches

Size                             Main-frame e.g ENIC, UNIVAC, EDVAC EDSAC

THE SECOND GENERATION:

Main Features/Characteristics:

Major innovation         Transistors were used as basic electronic component.

Main memory              ROM & RAM

External storage          Magnetic tapes and magnetic disks

Input/output                Magnetic tape for input punched cards and paper for out put.

Language                    Assembly language/some high-level languages

Operating system        Human operators to handle punched cards

Size                             Main-frame e.g IBM-1401, NCR-300, IBM-600etc

THE THIRD GENERATION:

Main features/Characteristics:

Major innovation         Integrated circuits (IC) wee used as basic electronic component

Main memory              PROM & DRAM

External storage          Improved disk storage

Input/output                keyboard & monitors for input & output

Language                    More high level language       

Operating system        Complete operating system were introduced that is less human

Size                             Mini-frame e.g. IBM System/360, ICL -360, Honey well model 316 etc

THE FOURTH GENERATION:

Main features/Characteristics:

Major innovation         LSI & VLSI ICs (microprocessors)

Main memory              EPROM & SRAM

External storage          Floppy disk and hard disk

Input/output                keyboard &n mouse are input and monitor is output device.

Language                    Fourth-generation languages and application software

Operating system        Operating System for microcomputers for example MS-DOS & PC-DOS

Size                             Microcomputers e.g IBM-PC Apple Macintosh etc.

THE FIFTH GENERATION:

Main features/Characteristics:        

Major innovation         ULSI, Ultra Large Scale Integration, ICs. This generation is also known as Artificial Intelligence (AI) generation.

Main memory              EPROM, SIMM & DIMM

External storage          Modified magnetic disks & optical disks.

Input/output                Key board, pointing devices, scanner etc, as input and monitor as main output devices

Language                    Al based software      

Operating system        GUI based operating system e.g. windows-95 windows-NT etc.

Size                             Very small in size e.g laptop, note books.

 

Generations of Computer