Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!ames!apple!motcsd!xdos!doug
From: doug@xdos.UUCP (Doug Merritt)
Newsgroups: comp.sys.amiga.tech
Subject: Re: MEMF_PHYSICAL?
Message-ID: <373@xdos.UUCP>
Date: 4 Jun 89 00:07:39 GMT
References: <8906030123.AA14671@jade.berkeley.edu>
Reply-To: doug@xdos.UUCP (Doug Merritt)
Organization: Hunter Systems, Mountain View CA (Silicon Valley)
Lines: 42

In article <8906030123.AA14671@jade.berkeley.edu> 451061@UOTTAWA.BITNET (Valentin Pepelea) writes:
>But when we are comparing operating systems with different memory models, we
>have to compare operating systems which offer the same other features. Doug
>is comparing an operating system with virtual memory, memory protection and
>separate addressing spaces to an operating system with virtual memory, no
>memory protection and a single addressing space.

Yes, I was at various times talking about various different things, 
and worse yet I was speaking about VM design in *general* rather than
what is most desirable on the Amiga; you're quite right that that clouded
the issue.

I finally realized this in my posting just *after* the one you replied
to most recently, and changed the Subject: line to reflect that an
entire proposal was contained therein.

Since I think I took pretty much everything into account in that one,
in a much clearer way, I'm going to defer comment on the current batch
of VM postings until I see some response to that one.

I'm saving these other postings in case a response is still called for
at that point.

>Doug's operating system:
>1. Slow context switches. Slow message passing. (requires MOVES instrucions)
>2. No real-time response. Needs real-time 'extensions' which basically consists
>   in implementing shared physical memory...
>3. Does not allow shared code, no shared libraries. Can be 'extended' to allow
>   these.
>4. Does not allow programs to monitor each other. Needs special operating
>   system primitives to allow debugging.
>5. As compatible with current AmigaOS software as MS-DOS software is.

I can see how you thought so, but truly none of these five points apply
to what I suggest in the actual proposal; you'll see. Sorry to have been
so unclear previously!
	Doug
-- 
Doug Merritt		{pyramid,apple}!xdos!doug
Member, Crusaders for a Better Tomorrow		Professional Wildeyed Visionary

"Welcome to Mars; now go home!" (Seen on a bumper sticker off Phobos)