[lug] Newbie Column - The Birth of Unix

[Wayde Allen]

Please feel free to correct any inacurracies, and/or add to these posts. 

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UNIX is one of the oldest operating systems in use today, and has its
beginnings in the development of the MULTICS operating system by MIT, Bell
Labs, and GE in the late 1960's. I don't know much about the
MULTICS experiment, but do know that after Bell Labs dropped out of this
research project several computer scientists at Bell Labs continued
tinkering with the ideas developed during the MULTICS experiment.
Evidently Ken Thompson at Bell Labs had developed a game, space travel, on
an old GE computer that was later ported to run on a spare PDP-7. This
project gave Ken Thompson, Dennis Ritchie, and Rudd Canaday the
experience needed to develop a new operating system for the PDP-7 based on
a new file system they had designed. This new operating system, was
capable of supporting two simultaneous users and was nicknamed
(UNICS) for Uniplexed Information and Computing System. This system
garnered some financial support from Bell Labs to continue its
development, and the name UNICS evolved into UNIX. 

In 1973, Ritchie and Thompson rewrote the UNIX kernel in the newly
developed C programming language. Up to this point UNIX, and all of the
other operating systems, had been written primarily in assembly language.
Using C greatly facilitated the maintainability and portability of the
UNIX. 

Since AT&T wasn't really in the computer business, their new operating
system was not offered commercially, but rather was licensed to
Universities and Government agencies. This, along with the availability of
the source code, ensured further development of the project, and spawned
several variants of the operating system: UNIX System V, Berkeley UNIX
(BSD) , Xenix (Microsoft), SCO, HP-UX, etc.. In recent history, there have
been several attempts to try and unify these variants. I'm not too certain
how effective these movements have been. It may be interesting to note
that one of the unification efforts, the Portable Operating System
Interface for Computer Environments (POSIX), is a joint IEEE/ANSI standard
supported by NIST. NIST's support of POSIX is due in part to the Federal
Information-Processing Standard (FIPS). However, I don't know the current
status of FIPS.

That is probably plenty history. There are many sources for more detailed
information if you are interested. Most of the above was "almost"
plagiarized from the Osborn-MagrawHill book: Rosen, Rosinski, Farber, UNIX
System V Release 4 - An introduction for New and Experienced Users. My
next post should cover the basic idea or "philosophy" behind the design of
the operating system. I'll also try to keep these a bit shorter too. 

- Wayde
  (wallen at boulder.nist.gov)