From: broeker AT acp3bf DOT knirsch DOT de (Hans-Bernhard Broeker)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Allocating DOS memory in Windows
Date: 3 Nov 1999 18:07:57 +0100
Organization: RWTH Aachen, III. physikalisches Institut B
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Tim Updegrove (tupdegrove AT lucent DOT com) wrote:
> This is a followup to a question on 10/15/99.  I'm trying to get a
> program which allocates DOS memory for a DMA buffer to work when booting
> to MS-DOS and also work in a MS-DOS box under Windows 98.  I can get
> each to work in a separate program but I'm hoping to find a solution
> that works both places in a single program.  Here are the steps that
> I've found to work.

> Booting to MS-DOS:
> 1. Allocate DOS memory and use the returned segment*16 for the physical
> DMA address and use the returned selector with _farpeekl and _farpookl.

> In a MS-DOS box with Windows 98:
[rather complicated way ...]

To me, this looks like you're overlooking the easy and obvious solution:

1) Allocate DOS memory with __dpmi_allocate_dos_memory

2) Use the returned segment together with _dos_ds in the _far*
   functions, or in _movedata().

AFAIK, this method is guaranteed to work under any DPMI server, i.e.
regardless wether you're using Windows, or raw DOS with CWSDPMI.
-- 
Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de)
Even if all the snow were burnt, ashes would remain.