Source : Free On-Line Dictionary of Computing

PS2
     
        {Sony Playstation}

PS/2
     
         {IBM}'s second generation of {personal computers}.
        The PS/2 series introduced three advances over the PC series:
        3.5" 1.44 megabyte {microfloppy} disks, {VGA} and {8514}
        graphics {display standard}s, and the {Micro Channel} bus
        architecture.  The 3.5" disks and VGA can be easily installed
        on other PCs and will become the standard for new compatible
        computers.  The Micro Channel bus allows for multiprocessing
        and less aggravation, but cannot be retrofitted to older PCs.
     
        PS/2 models 25 and 30 are {ISA}, other models have Micro
        Channel and {ESDI}.
     
        (1995-11-27)