From: cummings@hammer.Prime.COM (Kevin Cummings)
Subject: Re: New project:  S3 Acc. video support for Linux.
Keywords: S3, 86C911, X, local bus
Organization: Prime Computer R&D
Date: Mon, 13 Apr 1992 18:11:02 GMT

In article <1992Apr13.110732.836@gacvx2.gac.edu>, kraft@gac.edu (Steven Kraft) writes:
> To all who are interested in (or curious about) direct (local) bus video and S3  
> accelerated video cards being used with Linux:  
> 
> 	I have to decided to start discussion and development of S3 accelerated  
> video support in Linux.  

Being the owner of a brand spanking new Diamond Stealth VRAM S3 based video
card with 1MB of memory and the Hi-Color DAC, I share your interest in the S3
based video support category.

> 	This morning I received S3 Incorporated's manual on the "86C911 GUI  
> Accelerator."  I ordered it from Orchid Technology for $25.  If you want one  
> for yourself, just call Orchid's Tech Support and they will sell it to you.   
> (Numbers are below.)  The manual looks good, but I have only had a few minutes  
> to glance through it.  It states that:  "the S3 86C911 is a high-performance  
> GUI accelerator specifically designed to accelerate applications running under  
> Windows, Presentation Manager, and X."  I will try to contact S3 Inc. to see  
> what they might have already on the X driver.

Great news!  Maybe I should order up a copy, since Diamond doesn't provide
access to ALL the S3 supported modes in it's video BIOS.  On the other hand,
Diamond does provide a VESA BIOS, but it doesn't support all the S3 modes either.

> 	Now some info on the Fahrenheit 1280's modes.  The 1280 * [960|1024]  
> modes are interlaced.  The refresh rate can be set to 43 or 48 Hz.  The 640 *  
> 480 and 800 * 600 modes can be set to 60 or 72 Hz, and 1024 * 768 can be set to  
> 60 or 70 Hz.

So far, all this is pretty S3 standard, the Diamond supports these refresh rates
as well.

>               The primary way of setting refresh rates is through switches which  
> are easily accessible through a slot in the card's back panel.  A small  
> screwdriver is all it takes, no need to open the computer.

The Stealth only has 4 swithches on the back of its card.  Two of them help
select refresh rates.  I guess I'm lucky.  Two of these four states support the
NEC 3 and NEC 4/5 series monitors (I have a NEC 3D).

>                                                             The other way is a  
> resident driver for DOS (size of about 4k in memory I think) called FSCAN.  It  
> prompts you through setting the horizontal and vertical position adjustments  
> (to center the image at each resolution) and the refresh rates.

Diamond supplies an SMODE program to fine tune your video configuration, and select
other monitors or special frequencies/syncs/etc.

> Since the DOS utilities won't work  
> in Linux, refresh rates will need to be set using the switches.  

Yes, agreed, however, if we can figure out what the BIOSes are doing when they set
modes, maybe we can duplicate some of that in protected mode code so we don't need
the BIOSes (they're hard to access once LINUX gets running!).

> 	The various S3-based cards are basically the same except for setting  
> the modes or whatever.  (I could be wrong here.)  I think that they are very  
> much the same, and that if any changes are needed, #define's will do the trick.   
> I think that local bus video cards look just like a card on an ISA bus as far  
> as software drivers are concerned.  They have a memory address just like any  
> other video card.  The difference is that the data is sent to the card at 32  
> bits.  (Correct me if I am wrong.)

Uh, BIOS interfaces are probably card specific, though VESA support can help here.
As far as card interfaces, 8, 16, and 32 bits are all possible.  My card is a 16 bit
card with jumpers on board to restrict access to 8 bits if necessary (not recommended
in an AT+ class machine!).

> 	Soon I will start a channel on the linux-activists list for this  
> discussion.  If you have anything to contribute, please do, either through  
> email to me, the soon-to-be-created list channel, or comp.os.linux.

Great!  Please include me in your discussions!

Use either E-Mail address below if you start up a mailing list.   Thanx!

=================================================================
Kevin J. Cummings                       Prime Computer Inc.
20 Briarwood Road                       500 Old Connecticut Path
Framingham, Mass.                       Framingham, Mass.

Work:  cummings@primerd.Prime.COM
Home:  cummings@kjc386.framingham.ma.us

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		  I've come to the conclusion that your new
		  defense system SUCKS..."   --  War Games
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