Generation Number Technology Year of Introduction Specific Computer Remarks
1 Vacuum Tubes 1945 Mark 1, ENIAC, IBM 650 Wired circuits using vacuum tubes; punched cards as the main storage medium
2 Transitors 1958 ATLAS, B 5000, IBM 1401, ICL 1901, MINSK-2 Printed circuits with transistors; magnetic media as the storage
3 Integrated Circuits (SSI and MSI) 1966 IBM S/360, UNIVAC 1100, HP 2100 A Increased storage and processing  capabilities
4 LSI 1972 ICL 2900, HP 9845 A, VAX 11/780 Newer capabilities and reduced sizes
5 VLSI 1978 CRAY-1, CDAC-6600 Heavy parallelism