MULTICS

Multics
 /muhl'tiks/, n.

   [from "MULTiplexed Information and Computing Service"] An early
   timesharing {operating system} co-designed by a consortium including
   MIT, GE, and Bell Laboratories as a successor to {CTSS}. The design
   was first presented in 1965, planned for operation in 1967, first
   operational in 1969, and took several more years to achieve
   respectable performance and stability.

   Multics was very innovative for its time -- among other things, it
   provided a hierarchical file system with access control on individual
   files and introduced the idea of treating all devices uniformly as
   special files. It was also the first OS to run on a symmetric
   multiprocessor, and the only general-purpose system to be awarded a B2
   security rating by the NSA (see {Orange Book}).

   Bell Labs left the development effort in 1969 after judging that
   {second-system effect} had bloated Multics to the point of practical
   unusability. Honeywell commercialized Multics in 1972 after buying out
   GE's computer group, but it was never very successful: at its peak in
   the 1980s, there were between 75 and 100 Multics sites, each a
   multi-million dollar mainframe.

   One of the former Multics developers from Bell Labs was Ken Thompson,
   and {Unix} deliberately carried through and extended many of Multics'
   design ideas; indeed, Thompson described the very name `Unix' as "a
   weak pun on Multics". For this and other reasons, aspects of the
   Multics design remain a topic of occasional debate among hackers. See
   also {brain-damaged} and {GCOS}.

   MIT ended its development association with Multics in 1977. Honeywell
   sold its computer business to Bull in the mid 80s, and development on
   Multics was stopped in 1988. Four Multics sites were known to be still
   in use as late as 1998, but the last one (a Canadian military site)
   was decommissioned in November 2000. There is a Multics page at
   http://www.stratus.com/pub/vos/multics/tvv/multics.html.
    

Multics

   <operating system> /muhl'tiks/ MULTiplexed Information and
   Computing Service.  A {time-sharing} {operating system}
   co-designed by a consortium including {MIT}, {GE} and {Bell
   Laboratories} as a successor to MIT's {CTSS}.  The system
   design was presented in a special session of the 1965 Fall
   Joint Computer Conference and was planned to be operational in
   two years.  It was finally made available in 1969, and took
   several more years to achieve respectable performance and
   stability.

   Multics was very innovative for its time - among other things,
   it was the first major OS to run on a {symmetric
   multiprocessor}; provided a {hierarchical file system} with
   {access control} on individual files; mapped files into a
   paged, segmented {virtual memory}; was written in a
   {high-level language} ({PL/I}); and provided dynamic
   inter-procedure linkage and memory (file) sharing as the
   default mode of operation.  Multics was the only
   general-purpose system to be awarded a B2 {security rating} by
   the {NSA}.

   Bell Labs left the development effort in 1969.  {Honeywell}
   commercialised Multics in 1972 after buying out GE's computer
   group, but it was never very successful: at its peak in the
   1980s, there were between 75 and 100 Multics sites, each a
   multi-million dollar {mainframe}.

   One of the former Multics developers from Bell Labs was {Ken
   Thompson}, a circumstance which led directly to the birth of
   {Unix}.  For this and other reasons, aspects of the Multics
   design remain a topic of occasional debate among hackers.  See
   also {brain-damaged} and {GCOS}.

   MIT ended its development association with Multics in 1977.
   Honeywell sold its computer business to {Bull} in the mid
   1980s, and development on Multics was stopped in 1988 when
   Bull scrapped a Boston proposal to port Multics to a
   {platform} derived from the {DPS-6}.

   A few Multics sites are still in use as late as 1996.

   The last Multics system running, the Canadian Department of
   National Defence Multics site in Halifax, Nova Scotia, Canada,
   shut down on 2000-10-30 at 17:08 UTC.

   The {Jargon file} 3.0.0 claims that on some versions of
   Multics one was required to enter a password to log out but
   James J. Lippard <[email protected]>, who was a Multics
   developer in Phoenix, believes this to be an {urban legend}.
   He never heard of a version of Multics which required a
   password to logout.  Tom Van Vleck <[email protected]>
   agrees.  He suggests that some user may have implemented a
   'terminal locking' program that required a password before one
   could type anything, including logout.

   (http://multicians.org/).

   Usenet newsgroup: news:alt.os.multics.

   [{Jargon File}]

   (2002-04-12)
    

MULTICS
       MULTiplexed Information and Computing Service (OS, MIT, Bell)