Newsgroups: comp.arch
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: the Multics from the black lagoon :-)
Message-ID: <1990Feb7.221800.804@utzoo.uucp>
Organization: U of Toronto Zoology
References: <8859@portia.Stanford.EDU> <20571@watdragon.waterloo.edu> <49956@sgi.sgi.com> <4791@helios.ee.lbl.gov> <2093@crdos1.crd.ge.COM>
Date: Wed, 7 Feb 90 22:18:00 GMT

In article <2093@crdos1.crd.ge.COM> davidsen@crdos1.crd.ge.com (bill davidsen) writes:
>  I suspect that you have never used Multics and don't recall that UNIX
>was written because there was not enough access to Multics.

This is a rather drastic oversimplification.  Unix was not just "Multics
on a low budget", it was also "90% of the benefits at 10% of the cost".
Remember that Multics and OS/360 are the two classic examples of second-
system effect (overconfidence after a successful first system leads to
vast complexity and a union-of-all-wishlists approach on the second).
With the benefits of hindsight and a much more manageable system, Unix
ended up taking a lot of ideas much farther than Multics did.

>UNIX is just
>beginning to implement some of the ideas which have been working in
>Multics for two decades, such as mapping files to memory.

Gee, how could we ever have lived without that for two decades?  :-)
Maybe because we don't need it and it doesn't buy us very much?  Unix
evolution is now largely controlled by the marketdroids, who evaluate
systems by the length of the checklist of features.  All sorts of
silly and bizarre features are now crawling out of the woodwork and
burrowing into Unix as a result.  This does not necesarily mean said
features are good or desirable or even useful.

>  The only reason Multics is not where UNIX is today is that it was
>developed by one company which didn't know how to sell computers and
>then rights went to another...

I can think of several other reasons, actually, starting with Multics
being much larger, being much fussier about memory management and
such, and performing very poorly by comparison.  Unix did not suddenly
spring into its position of prominence when hardware reached current
levels -- it steadily grew into it through ability to run well on small
machines (most Unix machines were small until very recently) and ability
to port to almost anything.  Multics had no hope of ever copying that.
-- 
SVR4:  every feature you ever |     Henry Spencer at U of Toronto Zoology
wanted, and plenty you didn't.| uunet!attcan!utzoo!henry henry@zoo.toronto.edu