COMPUTER GENERATIONS •THE FIRST COMPUTERS WERE RESULTS OF WORLD WAR 2 DEVELOPMENTS, AIMED AT MILITARY USES •1944 AIKEN AT HARVARD MARK 1: FIRST ELECTROMECHANICAL DIGITAL COMPUTER (ELECTROMAGNETIC RELAYS -- MAGNETS OPEN AND CLOSES METAL SWITCHES). THE "FIRST GENERATION:” VACUMN TUBES •1946: ENIAC (Electronic Numerical Integrator and Computer) •FIRST ELECTRONIC DIGITAL COMPUTER, CONSTRUCTED WITH 17,000 VACUUM TUBES. EIGHT FEET TALL AND 80 FEET LONG. • EXTERNAL (WIRED) PROGRAM. •ENIAC could do 333 multiplications per second and cost the equivalent of $5- $10 million 4 SECOND GENERATION •USED SEMICONDUCTOR TRANSISTOR CHIPS DEVELOPED AT BELL LABS •1955 : IBM COMPUTER WITH 2000 TRANSISTORS. BY 1959, DELIVERIES MADE THE VACUMN TUBE COMPUTERS OUTMODED. INCLUDED VERY LARGE MAINFRAMES, SUCH AS THE IBM 7090, AND SMALLER MACHINES, SUCH AS THE IBM 1401. THIRD GENERATION •THE DISTINCTION AMONG SUBSEQUENT GENERATIONS IS NOT AS CLEAR AS THAT BETWEEN THE FIRST AND SECOND GENERATION COMPUTERS. •THIRD GENERATION IS CHARACTERIZED BY THE ABILITY TO SUPPORT MULTI-PROGRAMMING. COMPUTERS THAT USE INTEGRATED CIRCUIT TECHNOLOGIES ARE PART OF THE THIRD GENERATION (LSI, OR LARGE SCALE INTEGRATION). 5 THIRD GENERATION •AS PART OF THE THIRD GENERATION, WE ALSO SAW THE EMERGENCE OF "MINI-COMPUTERS”- •1968 DEC-- FIRST MINI •1972 IBM 370 SEMI-CONDUCTOR MEMORY CHIPS •60’S AND 70’S PUNCH CARD & BATCH PROCESSING STILL DOMINANT. Applications and Impacts • Through the first three generations of computers (40’s 50’s and 60’s) they were used almost entirely for business (payroll and inventory), government, and scientific computing. • Punch cards and batch processing. • In the 1970’s, integrated circuits began to to make computers smaller and cheaper. • 1974- first "personal computers” sold as kits • 1977 Wozniak and Jobs released the Apple II (first mass marketed PC) 6 FOURTH GENERATION •NO GENERALLY ACCEPTED DEFINITION OF FOURTH GENERATION. SOME SAY IT IS THE VLSI (VERY LARGE SCALE INTEGRATION) SUPERCOMPUTERS. •SOME SAY IT IS THE EMERGENCE OF THE MICROCOMPUTER IN THE FORM OF PERSONAL COMPUTERS AND WORK STATIONS. 1983 JAPANESE ANNOUNCE "5TH GENERATION” PROJECT •COMPUTERS THAT WILL TAKE SPEECH INPUT AND OUTPUT, IN "NATURAL LANGUAGE” •"Easy to use” computers require tremendous speed. By the end of the 20th century, speeds are measured in MIPS- millions of instructions per second. Many computers now do 1000 MIPS ( a billion instructions/sec)