X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f
From: RayeR <glaux AT centrum DOT cz>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: How to access 0xFF800000 data ?
Date: Fri, 2 Oct 2009 15:09:10 -0700 (PDT)
Organization: http://groups.google.com
Lines: 6
Message-ID: <75c9d2b1-6067-460a-98e6-ab578628ebbc@m11g2000yqf.googlegroups.com>
References: <850b568b-640c-435e-b6ca-deb8953ef1d5 AT y10g2000prf DOT googlegroups DOT com> 
	<cvWdnfdIDYbh1wLXnZ2dnUVZ_sadnZ2d AT earthlink DOT com> <1f6bf27d-a58c-4242-8411-acc03958afc2 AT x25g2000prf DOT googlegroups DOT com> 
	<5b184576-9f64-46a0-a183-97d812ce9a6d AT w36g2000yqm DOT googlegroups DOT com>
NNTP-Posting-Host: 94.113.157.229
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
X-Trace: posting.google.com 1254521350 28387 127.0.0.1 (2 Oct 2009 22:09:10 GMT)
X-Complaints-To: groups-abuse AT google DOT com
NNTP-Posting-Date: Fri, 2 Oct 2009 22:09:10 +0000 (UTC)
Complaints-To: groups-abuse AT google DOT com
Injection-Info: m11g2000yqf.googlegroups.com; posting-host=94.113.157.229; 
	posting-account=Q0wMHAoAAADjYrghh94FTf6YnbpTqZgp
User-Agent: G2/1.0
X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.23) 
	Gecko/20090825 SeaMonkey/1.1.18,gzip(gfe),gzip(gfe)
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

Simply,
WinXP (and all NT-based) don't allow accessing entire physical memory
for DOS applications. It's memory protection policy which became more
restrictive since ages of Win9x. The same for win32 apps in user mode.
You will need to write some kernel mode driver that will access
physicam memory and transfer data from/to your program.