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Mail Archives: djgpp/1996/12/28/17:06:27

Message-Id: <199612282157.WAA10028@math.amu.edu.pl>
Comments: Authenticated sender is <grendel AT ananke DOT amu DOT edu DOT pl>
From: "Mark Habersack" <grendel AT ananke DOT amu DOT edu DOT pl>
Organization: Home, sweet home (Poznan, Poland)
To: DJ Delorie <dj AT delorie DOT com>, djgpp AT delorie DOT com
Date: Sat, 28 Dec 1996 22:57:01 +0100
MIME-Version: 1.0
Subject: Re: DPMI incorporation...
Reply-to: grendel AT ananke DOT amu DOT edu DOT pl

Once upon a time (on 27 Dec 96 at 19:10) DJ Delorie said:

> > DPMI was designed for i386+ only and it would never run on
> > iAPX286- machines.
> 
> Not true.  See http://www.delorie.com/djgpp/doc/dpmi/ch4.1.html
> where it states "0=16-bit application" and "if running on an 80386
> or later".  DPMI supports 80286 and higher processors.  However, it
> only supports the 32-bit operations on 32-bit processors (of course)
True. I must've overlooked this statement. Nevertheless, I have never 
seen any successful implementation of DPMI for 286 machines (perhaps 
Windoze 3.xx was such?). Even if there were a server for 286 it would 
provide only a limited set of DPMI 0.9 functions.There is no 
provision in 286 to implement any of the page-related functions, nor the 
debbuging-related ones.

> > DPMI heavily relies on features found only in i386+ machines (like
> > paged memory).
> 
> Not true. Even the DPMI in Windows95 doesn't support the paged
> memory functions of DPMI 1.0.
My fault. I used a wrong expression. What I meant was that DPMI uses 
i386 memory pages to implement virtual memory. This is opposed to the 286 
VM scheme where memory is swapped out in segments, not pages.

_http://ananke.amu.edu.pl/~grendel_________________________
The more I see, the more I hear, the more I find fewer
answers. I close my mind, I shut it out but you know it's
getting harder to calm down, to reason out, to come to terms
with what it's all about! I'm uptight, can't sleep at night
I can't pretend everything's alright! My ideals, my sanity
they seem to be deserting me but to stand up and fight I know
we have six million reasons!

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