History  Generation 0  Charles Babbage ( )  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 that 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  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