From: "John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: putpixel in inline at&t asm
Date: Fri, 17 Oct 1997 22:48:05 +0000
Organization: Two pounds of chaos and a pinch of salt
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Anders Clerwall wrote:
> 
> Hi..
> How to I access the video memory in inline asm do, let's say, plot a pixel
> on the screen. I use a 'unsigned char *mcga;' pointer to the screen.
> Can anyone help.. Would appreciate it.

Direct access to conventional memory does not work in protected mode. 
The full subject is far too large to discuss here, but this is one of
the most commonly asked DJGPP questions and as such is given full
treatment in the DJGPP Frequently Asked Questions list (v2/faq210b.zip
from SimTel or online at http://www.delorie.com/djgpp/v2faq/).  Look
specifically in chapters 10, 17, and 18 for solutions to graphics and
other hardware-related coding in protected mode.  Also check out some of
the other user-created DJGPP resources, such as Brennan's DJGPP2+Games
Resources page at http://www.rt66.com/~brennan/djgpp/.  This page has
some of the best graphics and inline assembly tutorials on the net, as
well as pointers to numerous libraries that you can use to make your
graphics tasks easier.

hth

-- 
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|      John M. Aldrich       | "It may be better to be a live jackal|
|       aka Fighteer I       | than a dead lion, but it is better   |
|   mailto:fighteer AT cs DOT com   | still to be a live lion."            |
| http://www.cs.com/fighteer |                - Lazarus Long        |
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