IBM System/360 (and
IBM System/370)
The architecturally compatible line of
MainframeComputers whose success, following huge financial risk, allowed IBM (
InternationalBusinessMachines) to dominate the
BigIron business in the 1960s and 1970s. The whole project was led by
FredBrooks;
GeneAmdahl was the chief architect for the hardware.
Its logo was a compass rose, signifying the 360 degrees - the full circle - of computing applications that could be addressed with the System/360 architecture, replacing the previously customarily separate lines of commercially oriented
MainframeComputers versus scientifically oriented
SuperComputers.
Also the full software-compatiblity across (almost) the entire price range of 360 models, another "first" and one of the line's central achievements.
Brooks decided that it would adopt
EbcdicCode, an 8-bit character set including lower-case letters, another significant milestone for the time.
Its instruction set was summarized on a folding quick reference printed on mint-green
card stock, thus coming to be known throughout much of the computer industry as the
Green Card. The instruction set of its successor
System/370 architecture, whose fully developed models were characterized by
virtual memory and
cache features,
was printed on yellow or light-goldenrod card stock, and quickly dubbed the
Yellow Card.
While the hardware was considered a great success, the project to create the system software became a bellwether of the
SoftwareCrisis.
MythicalManMonth was mostly based on
FredBrooks' experience as head of the project.
CategoryMainframeComputing CategoryHardware CategoryComputerArchitecture