www.delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/1998/10/27/06:07:13

Message-ID: <8D53104ECD0CD211AF4000A0C9D60AE3235E64@probe-2.Acclaim-Euro.net>
From: Shawn Hargreaves <ShawnH AT Probe DOT co DOT uk>
To: djgpp AT delorie DOT com
Subject: Re: CWSDPMI Physical Memory Addresses
Date: Tue, 27 Oct 1998 11:02:49 -0000
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.0.1460.8)
Reply-To: djgpp AT delorie DOT com

Harold Roman writes:
> I am writing a progam that interacts with a card that does DMA 
> and is memory mapped. I need to get physical addresses for my 
> data buffers. I looked through the archives and found a "back 
> door" described by Charles Sandman (posted 9/22/96).

I can't advise you on this CWSDPMI issue, but I think that this 
may be a more complex approach than is really needed. If you use 
__dpmi_allocate_dos_memory() to set up some data buffers in 
conventional memory, you can then program the DMA controller 
directly with these addresses, and use functions like dosmemget() 
or _farpeekl() to fetch the data into your normal address space. 
IMHO this would be a lot simpler and more reliable than trying 
to directly map virtual addresses into physical ones...


	Shawn Hargreaves.

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019