[comp.graphics] VGA register programming

lance@motcsd.csd.mot.com (lance.norskog) (11/06/90)

Hello-

What are good references for VGA register-level programming?
In particular, do any books explain how to calculate register sets
for different speeds?  The Nanao 9060S is rated at 90khz, I was wondering
how to actually operate it at that speed.

Also, is it possible to program the VGA to be double-buffered?
That is, can you feed the screen from more than one memory chunk?

Lance
lance@motcsd.csd.mot.com
thinman@cup.portal.com

kulas@sunb2.cs.uiuc.edu (11/08/90)

You might have a look at Michael Abrash's book.  I forget the title.  Abrash
is the guy who writes the great PC graphics articles for Programmer's Journal.
The book is a collection of those articles.  If you pick up a recent copy of
Programmer's Journal, there is sure to be an advertisement for the book (full
page, if I recall).

A couple of his articles discuss graphics modes available on the standard VGA
which support double buffering.  You can double buffer 640x350x4(bit planes) on
an EGA (and so, of course, on the VGA).  I don't think you can double buffer
640x480x4 on the VGA due to the way memory would have to be organized.  Abrash
discusses some interesting modes, not supported by the BIOS, but available on a
vanilla VGA, which may be double buffered.  One of these is 320x400x8.

I would imagine at least one of his articles goes into depth on the kind of VGA
registers you're interested in, though I can't remember offhand.

Mike

herrickd@iccgcc.decnet.ab.com (11/08/90)

When my computer with an Orchid VGA came, the Orchid manual made
reference to a technical reference manual that Orchid would sell
and a phone number to order.  When the "manual" came, it was a
photocopy of the documentation for the Tseng Chip Set.  This kind
of source has always seemed more useful to me than derivative
books.

Call the technical assistance number in your VGA manual.

dan herrick
herrickd@astro.pc.ab.com

eli@aspasia.gang.umass.edu (Eli Brandt) (11/10/90)

Does anyone have a good reference for VGA text-mode register-tweaking? 
I have the _Programmer's_Guide_to_EGA/VGA..._, which lists the  
registers but really doesn't discuss text mode.  So far all I've managed
is a rather nice 92x50 and a disgustingly flickery 120xsomething-or-other.
And a lot of crashes and snow, of course.  Are there any books, papers,
examples of commented sources code, etc. out there?
Thanks...

Eli