Date: Tue, 27 Oct 1998 21:06:08 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: djgpp AT delorie DOT com
Subject: Re: CWSDPMI Physical Memory Addresses
In-Reply-To: <3634FD57.7034AA15@giganet.com>
Message-ID: <Pine.SUN.3.91.981027210547.8711U-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Reply-To: djgpp AT delorie DOT com


On Mon, 26 Oct 1998, Harold Roman 978-461-0402 Ext 223 wrote:

> 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). This technique uses the "sgdt"
> instruction to find the global descriptor table and the "str"
> instruction to find the current task structure.

Try the advice in section 18.14 of the DJGPP FAQ list (v2/faq211b.zip
from the usual DJGPP sites).  It describes a couple of ways to achieve
this that are much simpler than messing with SGDT.