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Mail Archives: djgpp/1998/10/27/10:57:55

From: Harold Roman 978-461-0402 Ext 223 <harold AT giganet DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: CWSDPMI Physical Memory Addresses
Date: Tue, 27 Oct 1998 10:45:48 -0500
Organization: GigaNet Inc.
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> 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).
>

Shawn Hargreaves wrote:

> 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...

Yes, that would be simpler. But, I really need to use mega-byte sized
buffers and I need for the buffers to be placed in any/all memory
locations for my card and my application. Thanks for the comments.

    Harold Roman


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