Source : Free On-Line Dictionary of Computing

IBM 360
     
         The generic name for the {CPU}s and architecture
        released by {IBM} in 1964.  The 360 was marketed as a general
        purpose computer with 'all round' functionality - hence 360
        (degrees).
     
        Models ranged from the 360/20 to the 360/65 and later the
        360/95, with typical memory configurations from 16K to 1024K.
     
        Elements of the architecture, such as the basic {instruction
        set} are still in use on IBM {mainframes} today.  Associated
        {operating systems} included {DOS}, {OS/MFT} and {OS/MVT}.
     
        The 360 architecture was based on an 8-bit {byte}, 16 general
        purpose {registers}, 24-bit addressing, and a PSW (Program
        Status Word) including a location counter.
     
        {Gene Amdahl}, then an IBM employee, is generally acknowledged
        as the 360's chief architect.  He later went on to found
        {Amdahl Corporaton}, a manufacture of {PCM} {mainframe}
        equipment.
     
        The 360's predecessors were the smaller {IBM 1401} and the
        large {IBM 7090} series.
     
        See also {ABEND}, {ALC}, {BAL}, {Big Red Switch}, {HCF}, {mode
        bit}, {PL360}, {PL/S}.
     
        (1999-01-24)