Generation Table of Computer

Generation	Duration	Memory Device	Features	Example
First	1942-1955	Vacuum Tubes or Valves	Ø used vacuum tubes as electronic circuit Ø magnetic drum for primary storage Ø mercury delay lined for memory Ø punch-card used as secondary storage Ø machine level programming used Ø operating speed was used in terms of millisecond	Mark-I, UNIVAC, ENIAC etc.
Second	1955-1964	Transistor	Ø magnet core memory used as internal storage Ø magnet tapes used as secondary storage Ø little bit faster I/O devices Ø high level language used as programming Ø processing speed measured in microsecond	IMB 1401, ICL 2950/10 etc.
Third	1964-1975	IC(Integrated circuits)	Ø semi conductor memory used as primary storage Ø magnetic discs were used as secondary storage Ø massive use of high level language Ø processing speed increased to nanosecond and even faster	IBM 360 series, UNIVAC 9000 etc.
Fourth	1975-1990	VLSI or Microprocessor	Ø massive use of magnetic and optical storage devices with capacity more than 100 GB Ø advancement in software and high level language Ø use of 4th generation language(4GL) Ø operation speed increased beyond picoseconds and MIPS (Millions of Instructions Per Second)	IBM PC, Pentium PC, Apple/Macintosh etc.
Fifth	1990+	Bio-Chips	Ø AI will make computer Intelligent and knowledge based Ø very high speed, PROLOG (programming language)	-