History Generation 0 Charles Babbage (1792-1871) Analytical Engine purely mechanical Ada Lovelace – first programmer

Generation 1 tubes WW II ’45-’55 Aiken – Harvard von Neumann – Princeton Zuse – Germany Eckert & Mauchley – U Penn

Generation 2 transistor ’55-’65 mainframes, punched cards, operators batch systems cards  1401  tape  7094  tape  1401  printer

Generation 3 ICs ’65 – ’80 System/360 “family” of systems Multiprogramming – multiple programs in memory at the same time sharing the CPU SPOOL – simultaneous peripheral operation online Timesharing – variant of multiprogramming for terminal and batch jobs

Gen 3 cont’d MULTICS Computer utility idea (kind of like internet servers) More ambitious than hardware could support MULTICS + PDP7 + Ken Thompson = Unix Unix variants: System V BSD IEEE POSIX Now Linux from Linus Torvalds

Gen 4 – 1980 to present VLSI 8080 CP/M also Z80 Apple I and II 8088 + MS-DOS (from Seattle Comp. Prod.) Apple Lisa (Xerox Star) Apple Mac Windows 3.1, 95, 98, NT (designed by David Cutler from DEC VAX/VMS), 2000, XP XWindows on Unix and Linux