From: kraft@gac.edu (Steven Kraft)
Newsgroups: comp.os.linux,alt.os.linux
Subject: New project:  S3 Acc. video support for Linux.
Keywords: S3, 86C911, X, local bus
Date: 13 Apr 92 17:07:30 GMT
Article-I.D.: gacvx2.1992Apr13.110732.836
Reply-To: kraft@gac.edu

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.  
	Consider the following scenario:  Suppose you are about to buy a new  
machine for Linux, and you find a motherboard with a proprietary direct bus  
SVGA card with an S3 chipset. It is very fast, but you are not sure if you  
should buy it since it's new and drivers may not be available yet.  You could  
also buy an S3 accelerated card for the ISA bus and stay with your current  
motherboard (or at least save a few bucks on the cost of a direct bus system),  
and get the benefits of S3 speed without the moderately higher price of a new  
motherboard with a direct bus.  So, should you buy a tried and true ET4000 card  
on an ISA bus system instead of newer technology?  
	(BTW, as I will mention later, Orchid does have the ProDesigner IIS/D  
which will let you have direct bus video and stay with an older video  
standard.)  
	I have an Orchid Superboard 486/33 motherboard with an Orchid  
Fahrenheit 1280/D 32 bit local bus video card.  Linux 0.12 works fine on it.  I  
hope to get 0.95c installed as soon as I can, and that will also work.  
	However, the fancy S3 accelerator chip functions of the Fahrenheit  
1280/D are not yet accessible to Linux (X Windows being one goal) since no  
driver has been written yet.  I hope to write that driver myself in the future,  
but I am still collecting info on that card.  
	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.
	
	I cannot say how long it might take to write the driver though...
	
	The beta version will be posted to an ftp site as soon as I have gotten  
that far and, of course, X Windows must be working also.  
	For now my video card looks just like any plain VGA card as far as  
Linux is concerned.
	To answer the question of how much faster the direct bus systems are  
than those on an ISA bus, I will discuss it briefly.  The Fahrenheit 1280/D is  
at least twice as fast as its 16 bit counterpart (the Fahrenheit 1280)  
depending on what kind of operation it is performing, according to benchmark  
results published by Orchid.  Since the Fahrenheit 1280 (the 16 bit card) is  
the second fastest S3 card reviewed recently in Byte magazine, it is no slouch  
either.  The 32 bit Fahrenheit 1280/D is a very fast video card, because it has  
both a fast S3 chipset design and a very fast direct bus.  
	Orchid does have another video card besides the Fahrenheit 1280/D for  
their Superboard motherboard's direct bus video slot.  It is the Prodesigner  
IIs/D, a very fast (non S3-accelerated) VGA card for those who want the  
standardization of VGA and the speed of direct bus video.
	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. 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 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.  Mine is set to  
72 Hz at 640 * 480 and 800 * 600, 60 Hz at 1024 * 768, and 48 Hz at 1280 *  
[960|1024].  These are the maximum refresh rates for all but the 1024 * 768  
mode.  My Samsung Syncmaster 4 is supposedly able to work at 70 Hz refresh at  
1024 * 768 but it doesn't for some reason.  Since the DOS utilities won't work  
in Linux, refresh rates will need to be set using the switches.  
	I will be writing this driver in my spare time :-), and it might be a  
while until I am done, but I will gladly work together with others even before  
a beta release is ready.  In the end it should be a lot faster than a generic  
ET4000 card because of 32-bit communication and bitblt's, etc.  And until this  
driver is ready, you can use these cards as standard VGA. 
	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.)
	Accelerated video will become a standard among OS/2 and Win users, so  
it will drop in price.  The number of Linux users who will have these will  
increase.  And we will be able to use X Windows once all the software is  
written. 
	
	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.
	
	If you would like to talk to Orchid about their systems, you can reach  
them at:
	Orchid Technology
	45365 Northport Loop West
	Fremont, CA  94538

	General line (800) 7-ORCHID
	Tech Support (510) 683-0323
	BBS          (510) 683-0327
	BBS (9600)   (510) 683-0555

P.S.
	I will also be working on a driver for Fractint, a DOS app that has  
been ported to X Windows and named XFractint.  We will, of course, be able to  
use XFractint once we get X Windows going under Linux to satisfy those of us  
who like fractal graphics, but some may want to have a driver available for DOS  
Fractint also.  Email me if you would like to be a beta tester for the DOS  
Fractint video driver.  
	Orchid has stated their intention to release an OS/2 2.0 driver for  
their Fahrenheit series in the near future.  If I get OS/2 before then, it  
won't be too much fun in 640*480.  (But what could be as much fun as Linux,  
anyway?)  


Steven Kraft KRAFT@GAC.EDU    Comp Sci major
Micro/Minicomputer Consultant
Gustavus Adolphus College, St. Peter, MN 56082
Newsgroups: comp.os.linux