From:	"John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: [Q] DPMI
Date:	Sun, 07 Sep 1997 23:32:31 +0000
Organization:	Two pounds of chaos and a pinch of salt
Lines:	39
Message-ID:	<3413398F.14B6@cs.com>
References:	<01bcbba9$47869240$4a4e04c3 AT default>
Reply-To:	fighteer AT cs DOT com
NNTP-Posting-Host:	ppp108.cs.com
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Thomas Jansen wrote:
> 
> i did a small programm with DJGPP in a dos-box under windows and now i want
> to start this one without windows in the background.. but it crashes.. i
> guess the reason is the heavy usage of several dpmi-routines (i write to
> video.memory by mapping it with "_dpmi_map_physical_memory()").. when i
> start with the dpmiserver by charles sandman, a page-fault comes up and if
> i start with qemm8.0 (can't get my hands on a newer qemm) the screen
> crashes.. what should i do? anyone had the same problems? any solution? is
> there a dpmi-server that supports v1.0?

Some more details might help us solve your problem.  DPMI 1.0 extensions
are only fully supported, at present, by the 386MAX DPMI host.  cwsdpmi
supports a small subset of 1.0 extensions, such as NULL page protection
and mapping physical memory into protected mode, but Windows 3.1 and
Windows 95 do _not_ support these.  If your program was running
successfully under Windows' DPMI host, then there is probably something
wrong with it besides simple incompatibility between hosts.

FYI, there were some difficulties with the memory management in early
versions of cwsdpmi, but if you're using the latest version (v3), there
shouldn't be a problem.

In the meantime, you might try using the vast variety of DJGPP debugging
tools to identify the location and cause of the page fault; this could
give you some good insights into the problem.  For information on
debugging tools, look in chapter 12 of the DJGPP Frequently Asked
Questions list, available from SimTel as v2/faq210b.zip or online at
http://www.delorie.com/djgpp/v2faq/.

hth

-- 
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|      John M. Aldrich       | "Sex should be friendly.  Otherwise  |
|       aka Fighteer I       | stick to mechanical toys; it's more  |
|   mailto:fighteer AT cs DOT com   | sanitary."                           |
| http://www.cs.com/fighteer |                - Lazarus Long        |
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