MULTICS
MULTICS 操作系统
MULTICS 操作系统
/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 , 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
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 )MULTiplexed Information and Computing Service (
OS ,
MIT ,
Bell )
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 .
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