Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!umich!umeecs!gilgalad
From: gilgalad@zip.eecs.umich.edu (Ralph Seguin)
Newsgroups: comp.sys.amiga.tech
Subject: Re: MMU + A3000 + AmigaOS2.0 == Non-crashing system?
Message-ID: <3024@zipeecs.umich.edu>
Date: 9 Aug 90 05:41:37 GMT
References: <2489@clinet.FI> <13624@cbmvax.commodore.com> <1990Aug6.115552.14352@sisd.kodak.com>
Organization: University of Michigan EECS Dept, Ann Arbor, MI
Lines: 37

In article <1990Aug6.115552.14352@sisd.kodak.com> jeh@athena.sisd.kodak.com (Ed Hanway) writes:
>valentin@cbmvax (Valentin Pepelea) writes:
>>In article <2489@clinet.FI> dix@clinet.FI (Risto Kaivola) writes:
>>>
>>> 1)If the OS2.0 does not support the MMU upto the extent where all
>>>   application programs could run independently, i.e not corrupting other
>>>   programs' data, can you tell me what is the reason?
>>
>>Backward compatibility.
>
>As an intermediate step to full memory protection, why not just forbid read
>and write access to free memory?  This won't do a thing to stop programs
>from corrupting each other, but it might help catch the bugs that cause
>these problems.  I think the only "correct" programs that might break
>under this scheme would be those that use the kind of non-standard memory
>allocation like VD0:.
>--
>Ed Hanway
>(speaking for myself, not my employer)

Why not make code segments read only as well?  This would kill off all
ugly self-modifying code.  
Personally, I th8ink that Commodore should define their paradigm and
present it to developers so that they can be prepared for it.  In any
case, I'm sure the people at Commodore are well aware of what is needed.

			See ya, Ralph

 
gilgalad@dip.eecs.umich.edu       gilgalad@zip.eecs.umich.edu
gilgalad@caen.engin.umich.edu     Ralph_Seguin@ub.cc.umich.edu
gilgalad@sparky.eecs.umich.edu    USER6TUN@UMICHUB.BITNET

Ralph Seguin               |  In order to get infinitely many monkeys to type
565 South Zeeb Rd.         | something that actually makes sense, you need to
Ann Arbor, MI 48103        | have infinitely many monkey editors as well.
(313) 662-1506