from
Jargon File (4.4.4, 14 Aug 2003)
PDP-11
Possibly the single most successful minicomputer design in history, a
favorite of hackers for many years, and the first major Unix machine,
The first PDP-11s (the 11/15 and 11/20) shipped in 1970 from {DEC};
the last (11/93 and 11/94) in 1990. Along the way, the 11 gave birth
to the {VAX}, strongly influenced the design of microprocessors such
as the Motorola 6800 and Intel 386, and left a permanent imprint on
the C language (which has an odd preference for octal embedded in its
syntax because of the way PDP-11 machine instructions were formatted).
There is a history site.
from
The Free On-line Dictionary of Computing (8 July 2008)
PDP-11
Programmed Data Processor model 11.
A series of {minicomputers} 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)