Source : Free On-Line Dictionary of Computing

PDP-10
     
         Programmed Data Processor model 10.
     
        The series of {mainframes} from {DEC} that made {time-sharing}
        real.  It looms large in hacker folklore because of its
        adoption in the mid-1970s by many university computing
        facilities and research labs, including the {MIT} {AI Lab},
        {Stanford}, and {CMU}.  Some aspects of the {instruction set}
        (most notably the bit-field instructions) are still considered
        unsurpassed.
     
        The PDP-10 was eventually eclipsed by the {VAX} machines
        (descendants of the {PDP-11}) when DEC recognised that the
        PDP-10 and VAX product lines were competing with each other
        and decided to concentrate its software development effort on
        the more profitable VAX.  The machine was finally dropped from
        DEC's line in 1983, following the failure of the {Jupiter}
        Project at DEC to build a viable new model.  (Some attempts by
        other companies to market clones came to nothing; see {Foonly}
        and {Mars}.)  This event spelled the doom of {ITS} and the
        technical cultures that had spawned the original {Jargon
        File}, but by mid-1991 it had become something of a badge of
        honourable old-timerhood among hackers to have cut one's teeth
        on a PDP-10.
     
        See {TOPS-10}, {AOS}, {BLT}, {DDT}, {DPB}, {EXCH}, {HAKMEM},
        {JFCL}, {LDB}, {pop}, {push}.
     
        {news:alt.sys.pdp10}
     
        [Was the PDP-10 a mini or a mainframe?]
     
        (2001-01-05)