Article View: comp.sys.amiga.tech
Article #7852Re: Help --> How to prevent the visit from the dreaded guru
From: Chris Hanson
Date: Sat, 05 Jan 1991 21:36
Date: Sat, 05 Jan 1991 21:36
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3058 bytes
In article <17130@cbmvax.commodore.com> jesup@cbmvax.commodore.com (Randell Jesup) writes:
> Correct. First of all, 80-90% of all Amigas do not have an MMU, and
>aren't likely too (though maybe eventually - nowhere near soon - low-end
>machines may have MMUs). Also, using protected-process-techniques for
>inter-process communication would slow down the OS a lot (unacceptably so
>on a 68000 machine). They add a lot of overhead, and add it even when there's
>no MMU in the system. Witness the Bill Gates comments that multitasking will
>require 4Meg, a 386, and your first-born son.
Couldn't you just make all inter-process communication be done using
MEMF_PUBLIC memory? As it was supposed to be? Since most people didn't do
this, Maybe make all the Message functions automagically force the
exchanged memory to be MEMF_PUBLIC temporarily. It'd be a pain, and a
megakludge, but it might work.
As for Bill Gates: Did anyone else notice the InfoWorld Christmas-list
column, wherein they suggested that he wants a Video Toaster for Christmas,
to produce his next "IBM/Microsoft invented/is-leading-the-market-in
multimedia" video?
> AmigaDos isn't likely to support protection any time soon - it's not
>designed for it, and attempting to add it would break almost any program that
>uses anything more complex than Dos functions (tty-style). This may be a
>(very slight) exaggeration, but it's mostly true. VM is far easier.
Agreed, adding protection might break large quantities of stuff. How
about some kind of retrofit? Create a new object file hunk, say HUNK_FLAGS,
which tells you intimate info about the program that LoadSeg is bringing in.
You could have a flag to signify "I'm a nice program and I work well under
memory protection, so protect me if you can". This would also be an
excellent place to finally settle the PURE code problem. Make a hunk flag
that signifies, regardless of what the FS bit says, "This code is pure,
damnit." ;)
>Randell Jesup, Keeper of AmigaDos, Commodore Engineering.
>{uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com BIX: rjesup
Chris - Xenon
--
#define chanson Christopher_Eric_Hanson || Lord_Xenon || Kelson_Haldane
I work, but you don't know who I work for. And they don't know I'm here.
"We apologize for the inconveniences." -GOD. (According to D. Adams)
Technical Details
Message-ID:
<1991Jan5.213642.16547@isis.cs.du.edu>Path:
arc1-ca.pugleaf.net!utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!clyde.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!apple!usc!wuarchive!uunet!isis!chansonReferences:
<611@caslon.cs.arizona.edu> <1991Jan4.224833.24914@ncsuvx.ncsu.edu> <17130@cbmvax.commodore.com>Show Full Headers
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Path: arc1-ca.pugleaf.net!utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!clyde.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!apple!usc!wuarchive!uunet!isis!chanson From: chanson@isis.cs.du.edu (Chris Hanson) Newsgroups: comp.sys.amiga.tech Subject: Re: Help --> How to prevent the visit from the dreaded guru Summary: Would this work? Keywords: Exec, Messages, Protected memory, MMU, Hunks, Caffeine. Message-ID: <1991Jan5.213642.16547@isis.cs.du.edu> Date: 5 Jan 91 21:36:42 GMT References: <611@caslon.cs.arizona.edu> <1991Jan4.224833.24914@ncsuvx.ncsu.edu> <17130@cbmvax.commodore.com> Reply-To: chanson@isis.UUCP (Chris Hanson) Organization: Matrix Lines: 43