From:	"Charles Sandmann" <sandmann AT clio DOT rice DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Mem mapped device questions
Date:	Mon, 28 Jul 1997 23:38:42
Organization:	Aspen Technology, Inc.
Lines:	13
Message-ID:	<33dd2d82.sandmann@clio.rice.edu>
References:	<33DBB874 DOT 57DF AT polbox DOT com>
Reply-To:	sandmann AT clio DOT rice DOT edu
NNTP-Posting-Host:	spica.dmccorp.com
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

> I think the access to memory mapped devices is more simple
> in DJGPP v1. I can simply use 0xE0000000 linear address instead
> of manipulating __dpmi_physical_address_mapping and other DPMI functions. 

While this is true, it's also more limited.  You can only access the first
256Mb of physical address space this way, and it doesn't work at all in 
enviroments like Windows/DPMI.  GO32 had some cool features, but unfortunately
Microsoft didn't consult DJ when they created DPMI 0.9- for windows..

> should the access to memory mapped device be faster/slower or
> the same comparing DJGPP v1 and DJGPP v2.

They should be the same.

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