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From: C506634@UMCVMB.MISSOURI.EDU (Eric Edwards)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Memory Protection!
Message-ID: <900816.150215.CDT.C506634@UMCVMB.MISSOURI.EDU>
Date: 16 Aug 90 20:02:15 GMT
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On 10 Aug 90 19:56:24 GMT Valentin Pepelea said:
>Another problem is that even if you provide the possiblity for new applications
>to run protected within the environment, the fact that older programs cann
>still
>jog around the address space and wreak havoc, defeats the initial purpose.
>Either you provide memory protection to everybody simultaneoulsy, or you
>don't at all.
Obviously we can't provide memory protection to everybody simultaneously.  For
the forseable future there will always be old programs that will not work
properly with memory protection and people that want to run them.  However,
memory protection is too valuable to just write off.

As has been mentioned before (I beleive) The operating system and unprotected
programs could be lumped together.  Protected programs would, of course, be
isolated from each other and the OS.

Now, what happens when an unprotected program tries to step on a protected.
program?  I'd call that a task held.  It's not very nice but at least it stops
the errant program from doing real damage.

Is this as good as "real" memory protection?  No.  But it's better than we have
now and starts the process going toward "real" memory protection.  In the
beginning it wouldn't be much differnt than now becuase protected programs
be few.   But if the memory in protected programs is larger than the OS then
errant programs will usually be stopped by protection violations.  This *would*
be more stable.  And as time progressed it would only get better.

Eric Edwards: c506634 @    "The 3090.  Proof that by applying state of the
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