Date: Wed, 9 Feb 94 14:15:00 CST
From: csaba AT vuse DOT vanderbilt DOT edu (Csaba A. Biegl)
To: djgpp AT sun DOT soe DOT clarkson DOT edu

>From csaba Wed Feb  9 13:58:50 1994
To: dridge AT MIT DOT EDU
Subject: Re:  Cirrus 6420 Video Chipset?

	From djgpp-bounces AT sun DOT soe DOT clarkson DOT edu Tue Feb  8 21:04:18 1994
	To: djgpp AT sun DOT soe DOT clarkson DOT edu
	Subject: Cirrus 6420 Video Chipset?


	I've got DJGPP set up on my WinBook portable which uses a Cirrus 6420
	Video Chipset.  It has 512K VRAM, and drives my monitor just fine
	in 800x600x256 under Windows.  I can't get anything to happen with
	DJGPP however...  the best it can muster is 320x200x256 - yuch.

	I am using an included (with the computer) VESA driver, and not specifying
	a video driver in the GO32 line... anybody know why it might still not
	be working?

	--------

	SE SYSTEMS:  Breakfast for your head!

I am not familiar with the Cirrus 6420 chip, but a couple of hints:

1) Use the VESAINFO program from the GRX distribution. If there is a 
   VESA BIOS extension (either ROM BIOS or TSR) on your system, this
   program will identify it and list all supported modes.

2) If VESAINFO works and lists graphics modes but these modes don't
   appear supported by GO32's (1.11!!) driver, then the only explanation
   I have is that the memory organization of these modes is incompatible
   with GO32's paging scheme. The built-in driver performs extensive
   checks on the mode parameters reported by the VESA BIOS before 
   adding the mode to the list of supported modes. If the mode is
   incompatible with the GO32 paging scheme then it is rejected.

Csaba Biegl
csaba AT vuse DOT vanderbilt DOT edu