Message-ID: <D1FB30BBA491D1118E6D006097BCAE391C0F14@Probe-nt-2a.Probe.co.uk>
From: Shawn Hargreaves <ShawnH AT Probe DOT co DOT uk>
To: Shawn Hargreaves <ShawnH AT Probe DOT co DOT uk>,
        Eli Zaretskii
	 <eliz AT is DOT elta DOT co DOT il>
Cc: djgpp AT delorie DOT com
Subject: RE: Allocate physical memory?
Date: Thu, 26 Mar 1998 15:03:31 -0000
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Eli Zaretskii writes:
> I think that since CWSDPMI uses services provided by the memory 
> manager (if there is one) to get memory from the system, and the 
> memory manager also provides the VDS services, this problem is 
> taken care of automagically. 

I don't understand how that could be possible. My understanding
(which admittedly may be totally wrong, since I don't have any 
experience of using EMS, XMS, or suchlike systems), was that CWSDPMI
will call these functions to allocate the physical memory space it
needs, but that the protected mode mappings for this memory is then
entirely an internal matter for the DPMI to take care of. Surely
the memory manager doesn't have any access to the CWSDPMI page tables,
or any way to rearrange these pages? A VDS implementation needs the
ability to remap things at the virtual memory level, and I didn't 
think this could be done without the involvement of the DPMI server.

This isn't really important because I can get it working under win95
before I start to worry about a clean DOS implementation, but if
DJ or Charles is reading this, it would be great to have an 
authoritative answer on whether VDS is currently possible when
running under CWSDPMI...

	Shawn Hargreaves.