Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!corton!chorus!opera.chorus.fr!mir
From: mir@opera.chorus.fr (Adam Mirowski)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: IBM's Professional Graphics Adaptor
Keywords: PGA,EGA,WP
Message-ID: <7880@chorus.fr>
Date: 14 Feb 91 14:52:48 GMT
References: <16369@milton.u.washington.edu>
Sender: mir@chorus.fr
Reply-To: mir@opera.chorus.fr (Adam Mirowski)
Organization: Chorus systemes, Saint Quentin en Yvelines, France
Lines: 58

In article <16369@milton.u.washington.edu>, johnston@milton.u.washington.edu (Craig Johnston) writes:
%% 
%% 	I have recently come to use a machine (AT) that has an IBM professional
%% graphics adaptor (PGA) installed.  It is set to emulate a CGA for nearly
%% everything it does.  A couple of applications that they have on this machine
%% will recognize the PGA, and make use of it (Design CAD).  What I would like,
%% is some sort of driver/TSR/trick, that would allow more programs to use the
%% high resolution/multicolor graphics modes that it is apperently capable of
%% displaying.  I`ve seen programs that allow a Hercules to emulate a CGA (or vv),
%% and I thought there might be something out there that would do the same for
%% the PGA; like PGA->EGA for instance.  It is frustrating to see the high
%% resolution graphics that it can do, and then have to view your WordPerfect
%% documents in CGA mode. :(
%% 	Perhaps someone could give me some pointers along these lines.  I
%% would also like to know just what this PGA can do.  Any info would be greatly
%% appreciated.  Please mail me.

When I was a student, our CC has bought a bunch of machines equipped
with PGA clones made by Matrox.  As some docs and demo diskettes came
with them, I had the opportunity to use the high resolution mode, to
write a fairly complete Turbo Pascal Interface and some simple programs.
A pal adapted it later to Turbo C.

The card is quite powerful (at least the Matrox clone was). You can
directly manipulate 3D, 2D and bitmap scenes through the comand language,
using arbitrary coordinate system. 4096 colors are available (Matrox has
16 millions), 256 at a time. But palette manipulation is slow, because
of the absence of a built-in shift. Also, Matrox text mode was 640x400,
not CGA.

No, there is no chance to make an EGA/VGA from it :-).  The CC people
hoped like you in the beginning too...
The communication with the card goes through a 1Kb shared memory,
which is organized as three 256 bytes FIFOs and some shared variables.
You write ASCII or binary commands into the input FIFO, read card
responses from the output FIFO and error messages from the error FIFO.
Shared variables are the pointers.

(In fact, on a 386 it could be possible to turn memory writes into
 PGA orders and reads into reads from a cache...)

It could be VERY easy to write a BGI driver to use the card with
Borland languages (using the bitmap set of commands). But at the
time, the BGI standard wasn't publicly available and later I have
already bought my own machine.

As for Windows... I don't know the standard for their graphics drivers.
Also these drivers are usually 70Kb in size -> too much effort.

Through a TSR program you can switch between the two modes.

Also some years ago, Dr Dobbs published a program that can turn the PGA
screen into a DOS device, for output only. I have a copy, but no diskette.

If you want some of these 'works', mail me.
-- 
Adam Mirowski,  mir@chorus.fr (FRANCE),  tel. +33 (1) 30-64-82-00 or 74
Chorus systemes, 6, av.Gustave Eiffel, 78182 Saint-Quentin-en-Yvelines CEDEX