CS 227 lecture -*- Outline -*- * computers (Scheme and the Art section 1.2) ** are amazing ------------------- A BIT OF HISTORY ELECTROMECHANICAL COMPUTERS 1939 Zuse-2 cost: $90000 mult time: 10 sec! VACUUM TUBES 1939 ENIAC (18000 tubes, 30 tons) cost: $100000 mult time: 50 usec 1959 IBM 704 and its ilk (vacuum tubes) SINGLE TRANSISTORS 1960 IBM 360 series INTEGRATED CIRCUTS 1971 IBM 370 series VLSI 1987 Sun 4 workstation cost: $10000 mult time: 400 nsec ------------------- Sun 4 is about 25 million times faster than the Zuse-2 costs about 225 million times less money to multiply numbers! (and currently costs about $2000 or so) Analogy: imagine if cars improved at the same rate 1938 Cadilliac costs about $30,000 top speed: 60 mph; economy: 15 mpg if cars improved at the same rate as computers 1987 Cadilliac costs about $3,300 top speed: 2 * c (twice speed of light) economy: 3 billion mpg in 1993 costs $700... source: Hans Moravec "Mind Children" (Harvard, 1988) as quoted in D. Crevier "AI" (Basic Books, 1993) ** are new many of the pioneers of computing are still alive (and attending conferences!) e.g., inventors of FORTRAN, Pascal, C, Scheme, LISP, all alive ** architecture ------------------------- A COMPUTER network mouse keyboard monitor ^ ^ ^ ^ v v v v <===============================> bus ^ ^ v v CPU <===> cache disk ^ v memory ------------------------- CPU = central processing unit (where compter adds, etc.) contains registers including the "program counter" disk stores your data (survives when you turn power off) each of the things written in lower case is really some complex electronics (a controller) all these are electronic, like a digital watch, or TV set no matter what inputs you give it, the computer doesn't care and can't be hurt by them.