From:	jpdelprat AT teaser DOT fr (JP)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: How to determine the physical address from a DPMI descriptor
Date:	Sun, 23 Aug 1998 18:10:52 GMT
Organization:	Guest of France-Teaser
Lines:	32
Message-ID:	<35e04c8f.1705102@news.teaser.fr>
References:	<Pine DOT SUN DOT 3 DOT 91 DOT 980823162729 DOT 1451D-100000 AT is>
NNTP-Posting-Host:	ppp2816-ft.teaser.fr
NNTP-Posting-Date:	23 Aug 1998 17:59:51 GMT
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> wrote:

>
>On Tue, 18 Aug 1998, JP wrote:
>
>> My need is to create and lock a 2Mo continuous buffer (under Windows
>> 95), and determine its physical address to give it to a video capture card.
>
>I think section 18.7 of the FAQ should get you started.
>
>> With DPMI functions (under Windows 95), I allocate my buffer then 
>> lock it, but despite the call to dpmi_lock_linear_region, the buffer
>> is still mixed and partially swapped out.
>
>Did you remember to make your segment to have a size that's a multiple of 
>4KB?

Thanks for the advice. I hadn't noticed this point. Fortunately, my
buffer is exactly 2M. So it should be ok. 

I have found another solution : I allocate and lock an xms buffer
before Windows starts. This buffer is continuous and cannot be used by
Windows. The drawback is that my system now has less memory. I would
prefer to allocate my buffer when I run my program, but I could find
any way.

Thanks very much, 
  JP
Jeepy (Jean-Pierre Delprat)
jpdelprat AT teaser DOT fr
www.teaser.fr/~jpdelprat (JPTUI home page)

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