IBM System360 1964 IBM System360 overview z Announced

IBM System/360 – 1964

IBM System/360 overview z Announced in 1964 z First shipped in 1965 z Six models initially announced (ultimately more than a dozen shipped) z 40 compatible peripherals z 100 other devices (e. g. , 029 card punch)

Before System/360 z Every machine was custom y Basic market target x. Business, scientific • For IBM, the 1401 character-oriented business machine, and the 7090 / 7094 scientific machine y Word length x 16 bits, 20 bits, 32 bits, 36 bits, variable y Arithmetic x. Binary, decimal y Operand addressing x 1 -address, 2 -address, 3 -address y Registers tended to be special-purpose (accumulator, index, PC) y Operating system

System/360 innovations z 8 -bit byte z Byte-addressable memory z 32 -bit words z 2’s complement arithmetic z Commercial use of microcoded CPUs z IBM Floating Point Architecture z EBCDIC character set z I/O architecture (channels), PSW, SVC z Many brilliant tradeoffs (e. g. , instruction format, halfword alignment, etc. ) z A family

Performance range at announcement z Core memory: 8 K bytes -> 8 M bytes (x 1000) y 60 x previous largest available z Cycle time: 1 usec -> 200 nsec (x 5) z Processing speed: x 50 y From 1401 to 2 x previous fastest IBM system (Far greater performance range over time)

IBM System/360 family 1964 30, 40, 50, 62, 70 1965 1966 20, 25 44 65, 75 67 1968 1969 1970 Baby scientific machine (FPRs) Focused on small business 85, 91, 95 DAT cache 195 S/370

z IBM 2314, 1965 y 233 MB y $256, 000 (x 6!) y 60 msec latency y. 312 MB/sec xfer y $1099/MB (x 6!) z From Dell, 2006 y 500 GB y $300 y 10 msec latency y 375 MB/sec xfer y $0. 0006/MB z Improvement ratio y 2000 y 5000 y 6 y 1000 y 10, 000

© 2004 © 2006 Jim Gribble, Gray, Microsoft Lazowska, Corporation Levy

IBM System/360 people z Fred Brooks, project manager z Gene Amdahl, architect z Gerry Blaauw, architect (many aspects incl. Model 67) z 819 pages of further information … IBM’s 360 and Early 370 Systems Emerson W. Pugh, Lyle R. Johnson, and John H. Palmer MIT Press, 1991