Path: utzoo!attcan!uunet!steinmetz!davidsen
From: davidsen@steinmetz.ge.com (William E. Davidsen Jr)
Newsgroups: comp.unix.questions
Subject: Re: Is UNIX(TM) Multi-User?
Message-ID: <11945@steinmetz.ge.com>
Date: 22 Aug 88 19:06:04 GMT
References: <880@taux01.UUCP> <213@bhjat.UUCP> <1640@uop.edu> <Aug.12.22.31.31.1988.1843@topaz.rutgers.edu> <404@cpro.UUCP> <15287@shemp.CS <365@pigs.UUCP>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: General Electric CRD, Schenectady, NY
Lines: 34

In article <365@pigs.UUCP> haugj@pigs.UUCP (Joe Bob Willie) writes:

| is unix REALLY a multi-user operating system?  or does it just act that
| way because it is a multi-tasking o/s?  i know most of the actual history
| behind unix, and i recall reading once that dennis didn't consider unix
| to even be an operating system.

  Any multitasking o/s can be a multiuser system, provided that the user
agent (shell or whatever) is a normal process. Given this, you can have
multiple user agents running, connected to several users.

  Note that this does not claim that any such o/s will work WELL for
multiple users, since the issue of response, etc, may make a system
impractical with more than one user. The dispatcher must give the CPU to
the correct processes to allow adequate response, often enough enough
to give the illusion of continuity, keep long running jobs going, and do
all of this without using all the resources of the machine deciding who
runs next.

  It is desirable to have a memory manager which can swap and/or move
processes in such a way that useful work can be done in a reasonable
memory space. It is desirable to have front end processing of incoming
characters, either in something like a device driver, or using a
separate front end communications computer.

  In my opinion, any multasking system fits the definition of multiuser,
but there are a lot of other details which make it a GOOD multiuser
system.

  Comments, clarifications, etc will undoubtedly follow.
-- 
	bill davidsen		(wedu@ge-crd.arpa)
  {uunet | philabs | seismo}!steinmetz!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -me