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From: freed@aum.UUCP (Erik Freed)
Newsgroups: net.micro.amiga
Subject: Re: Amiga MMU question
Message-ID: <397@aum.UUCP>
Date: Wed, 30-Oct-85 08:21:57 EST
Article-I.D.: aum.397
Posted: Wed Oct 30 08:21:57 1985
Date-Received: Sun, 3-Nov-85 07:49:19 EST
References: <192@ucdavis.UUCP> <141@amiga.amiga.UUCP>
Distribution: net
Organization: The Aurora Systems Bunch
Lines: 28

> >  A question for the Amiga experts.  I don't pretend to be an expert on the
> >subject, but doesn't a multitasking enviroment need some sort of memory
> >protection to keep processes from clobering each other.It is my understanding
> 

> Multitasking does NOT require an MMU.  Processes are allocated separate
> places in memory, and then are timesliced (the same way one would if one
> did have an mmu...).  There is no protection between different processes.
> One could write a program that trashes memory, and therefore the system
> (hence the infamous "GURU MEDITATION...").
> 
> Correctly written programs run without any problems, however.
  ^^^^^^^^^^^^^^^^^
> 

I think that this statement should be shanged to "bug free" software should
run without any problem. For single user systems this might be reasonable.
The place where you need the MMU is where there are multiple users each of
which could be in the process of debugging software. I will be interested,
now that there are alot of multitasking no-protection systems around, to see if
they are usable in a professional scenario where a crash could do more harm
than just annoy the user...
-- 
-------------------------------------------------------------------------------
                           Erik James Freed
			   Aurora Systems
			   San Francisco, CA
			   {dual,ptsfa}!aum!freed