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Path: utzoo!mnetor!uunet!nuchat!sugar!peter
From: peter@sugar.UUCP (Peter da Silva)
Newsgroups: comp.sys.amiga
Subject: Re: The Next Generation
Message-ID: <1217@sugar.UUCP>
Date: Thu, 3-Dec-87 13:47:24 EST
Article-I.D.: sugar.1217
Posted: Thu Dec  3 13:47:24 1987
Date-Received: Wed, 9-Dec-87 07:29:36 EST
References: <2785@megaron.arizona.edu> <17218@glacier.STANFORD.EDU> <582@zippy.eecs.umich.edu>
Organization: Sugar Land UNIX - Houston, TX
Lines: 51
Keywords: MMU paging swapping

In article <582@zippy.eecs.umich.edu>, pla@zippy.eecs.umich.edu (Paul Anderson) writes:
> Peter, I understand your points about paging, swapping and VM, but I'd
> like you to understand my point that anything less than virtual
> memory+paging+interprocess protection is a hack...

Well, you apparently don't understand it, because I have never said I don't
want interprocess protection. I also would like paging if I can safely
turn it off (not lock a process into memory... turn it off completely)
when I want to run real-time (like, in a video game). During program
devlopment and for some soft real-time work it is an absolute win.

> My experience is that the Amiga is about 1/4 the effective system
> speed of my Apollo DN3000.  An awful lot of this has to do with the
> quality of the software on the system, including compilers, debuggers,
> unix-type utilities, and other related things.

An awful lot has to do with the fact that you're using a faster CPU with
a faster bus and a faster hard disk, and you're not using TRIPOS. TRIPOS
is a bug come to life, and has nothing to do with VM. It's an orthogonal
issue.

> Anyone that thinks that
> the quality of the software on the Amiga even remotely approaches the
> quality of the system software on the Apollo really should try porting
> 10 or 15 megabytes of software to both before claiming it as fact.

I never said nor hinted this. The quality of UNIX software and tools
is awesome. Apollo's O/S seems to be in the ballpark.

> Your comment about software breaking without MEMF_PUBLIC is well taken,
> also.  Someone earlier (lost the article, sorry) mentioned that message
> passing OS are wonderful.  Well, they are, but things like MEMF_PUBLIC
> are part of the price we paid for AmigaDOS.

I don't see where MEMF_PUBLIC is such a problem. How much of your code
is public? What's the chance that in a protected system a bad pointer
will hit it before the much larger proportion of protected memory?

> My personal suggestion is for Commodore to forget trying to slowly add
> virtual memory to AmigaDOS... freeze what we know as AmigaDOS...
> [and get AmigaDOS emulator under UNIX, or UNIX/AmigaDOS under some
> sort of combined system].

Nope. Get UNIX onto the Amiga, and then let people run with it while you
get back to work on fixing AmigaDos. It's got advantages over UNIX. Real-time.
Works with floppies only. Etc...

Merge them when you KNOW you can do it right.
-- 
-- Peter da Silva  `-_-'  ...!hoptoad!academ!uhnix1!sugar!peter
-- Disclaimer: These U aren't mere opinions... these are *values*.