[comp.sys.ibm.pc.misc] PGA compatibility.

uhhyung@MANI.KAIST.AC.KR (Uhhyung Choi) (03/09/91)

	Hello?
	I have some questions on PGA Compatibilities.
	IS PGA COMPATIBLE WITH CGA OR EGA?
	Any comments on this will be helpful.
	I'd prefer e-mails.
	Thanks.

	Uhhyung Choi
	uhhyung@mani.kaist.ac.kr

mir@opera.chorus.fr (Adam Mirowski) (03/11/91)

In article <9103091404.AA02310@mani.kaist.ac.kr>, uhhyung@MANI.KAIST.AC.KR (Uhhyung Choi) writes:
%% 	I have some questions on PGA Compatibilities.
%% 	IS PGA COMPATIBLE WITH CGA OR EGA?
%% 	Any comments on this will be helpful.

IBM PGA was compatible with CGA only. Matrox had a PGA compatible board
that had a better text-mode CGA emulation (twice vertical resolution).

However, the compatibility is a bit peculiar: CGA screen can coexist
with the PGA screen, and you switch the display with a simple I/O
operation. Just as if you had two cards connected to a single display
through a switch.

Matrox CGA emulation wasn't very good in graphics mode. Microsoft Word
had problems with it.
-- 
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