Message-ID:	<32FE66E9.272F@pobox.oleane.com>
Date:	Mon, 10 Feb 1997 01:08:09 +0100
From:	Francois Charton <deef AT pobox DOT oleane DOT com>
Organization:	CCMSA
MIME-Version:	1.0
To:	KaRNaGE <dlydiard AT linknet DOT kitsap DOT lib DOT wa DOT us>
CC:	djgpp AT delorie DOT com
Subject:	Re: VBE 2.0 Pmode Bank Switching...
References:	<Pine DOT SUN DOT 3 DOT 95 DOT 970208215834 DOT 13653A-100000 AT linknet DOT kitsap DOT lib DOT wa DOT us>

KaRNaGE wrote:
> 
> Video Card: Cirrus Logic SuperVGA (CL-GD5422) with 1 Mb
> RAM DAC:    Cirrus Logic 24 bit DAC
> Clock Chip: Cirrus 5422/24/26/28 Internal Clock
>  . Installing VBE 2.0 32 bit protected mode extensions
> 

I had one of those (well I still have it, but the machine it is installed 
on refuses to boot...), and experienced several problems with it, when 
trying to use it in VESA modes... Garbage on the screen, errors in the 
detection: it reported 1MB video memory, whilst my card only had 512k. I 
guess it is only half-VESA compliant...

Here is some basic information on how to program it directly (I can send 
you the programs if you want, but it was written for DJGPP v1.x, and will 
require some work to port it to v2.x).

> (this is for mode 101h - 640x480x256)

This mode is 0x005F, so ax=0x005F, int(10h) would do.

Bank switching is done by

outportb(0x3CE,0x09);
outportb(0x3CF,bank_address);

bank_adress being the starting adress for the bank (bank_nr * 16).


This info (and more) can be found in vgadoc4b.zip on simtel, directory
msdos/vga.
Also, routines for the Cirrus54xx can be found in Allegro.

Hope this helps
Francois

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