Source : Free On-Line Dictionary of Computing

PDP-11
     
        Programmed Data Processor model 11.
     
        A series of {minicomputer}s based on an {instruction set}
        designed by C. Gordon Bell at {DEC} in the early 1970s (late
        60s?).  The PDP-11 family, which came after, but was not
        derived from, the {PDP-10}, was the most successful computer
        of its time until it was itself succeeded by the {VAX}.
     
        Models included the 11/23 and 11/24 (based on the F11
        chipset); 11/44, 11/04, 11/34, 11/05, 11/10, 11/15, 11/20,
        11/35, 11/40, 11/45, 11/70, 11/60 ({MSI} and {SSI}); LSI-11/2
        and LSI-11 (LSI-11 chipset).  In addition there were the 11/8x
        (J11 chipset) and SBC-11/21 (T11 chip) and then there was
        compatibility mode in the early {VAX} processors.
     
        The {B} and {C} languages were both used initially to
        implement {Unix} on the PDP-11.  The {microprocessor} design
        tradition owes a heavy debt to the PDP-11 {instruction set}.
     
        See also {SEX}.
     
        (1994-12-21)