From:	pneyz <pneyz AT armory DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Screen Offset register + Gravity Force
Date:	Tue, 09 Dec 1997 23:30:26 -0800
Organization:	Smoof Team
Lines:	16
Message-ID:	<348E4512.32ECB120@armory.com>
References:	<348E198F DOT 4CAE AT manc DOT u-net DOT com>
NNTP-Posting-Host:	scz-ca17-22.ix.netcom.com
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

> I've sussed waiting for the vertical blank in machine code
> (kind of!) but have probs with screen offsets and pages/double
> buffering etc.  I know the screen is at 0xA0000 but what PORT is the
> x/y offset for a particular page? (I know 0x13 -> 0x3D4, 0x3D5 is the
> virtual page width but so far to no avail..)

You should check out Denthor's VGA Trainer Program, which was originally
for Pascal but has been converted (partly) to C by Snowman/Hornet. You
can find it at http://www.hornet.org/code/tutors/denthor (tut??new.zip).
It will teach you all you need to know. By the way, I have found it
easier to just use pointers to 64k blocks of memory for virtual pages.
That alone is reason enough to get DJGPP since it's so much easier to
handle that much data.

				pneyz[smoof.ganja]
				"Fine Malt Coding"

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