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From: david@kessner.denver.co.us (David Kessner)
Newsgroups: comp.os.msdos.programmer,comp.graphics
Subject: Double Buffering on a ATI VGA Wonder
Message-ID: <1991May20.063352.1561@kessner.denver.co.us>
Date: 20 May 91 06:33:52 GMT
Organization: Kessner, Inc.
Lines: 30

Here is the story...  I have a 512K ATI VGA Wonder board and have written
several routines to support it's 256 color modes-- like a blindingly 
fast line drawing function.

I am doing rather complex 3-D animations and have also been very
sucsessful at that also.  (I've been rotating a wire frame couch at
26 frames/sec, amung other things-- using floating point even!).

What I need now is how to double buffer the display.  What I'd like to do
is use a 640x400 display mode (which uses almost 256K of RAM) and divide
the video RAM into two logical "screens".  Then display one while drawing
on the other.  Sounds simple enough.  While I have been doing graphics
for quite some time, VGA programming is another thing-- but I am not
afraid to get my hands dirty with some assembly...

So, how do I do this?  BIOS Calls?  VGA Register programming?  (I am also
not afraid to make this ATI VGA Wonder specific-- read on.)

While code fragments would be nice, an answer like, "Look up INT 10h
Function ??, etc" would suffice quite nicely...

While on the subject... This program(s) are really for my own amusement
and learning-- but if you happen to own a 512K VGA Wonder and a math
chip (386 prefered, as well as an IIT 3c87 FPU) I'd be willing to share
what I have-- which is minimal but could spin store logo's for you...

-- 
David Kessner - david@kessner.denver.co.us            |
1135 Fairfax, Denver CO  80220  (303) 377-1801 (p.m.) | Reunite PANGEA!
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