Notes about S3 chipset and VGA to TV converter
S3 based chipsets are one of the most common PC grapahics chipsets on the market and used by very many graphics cards makers. Unfortunately my VGA to TV converter system does not work properly with many S3 chips (it works nicely with almost all other fully VGA compatible chipsets).
Not all S3 chipser versions or cards have although this problem. I have also received some success stories with S3 cards (like one with Diamond 2001 Video graphics card whcih use S3 trio 64 chipset, it has been reported well with DOS and Windows).
Normal VGA to TV drivers can't be used
For some strange reason none of the drivers has been found to work properly on some S3 chipset. At the best you might get textmode and some graphics modes to work (but VGA mode 13h 320x200 with 256 color never work). There are not enough S3 information freely available to write S3 chipset specific drivers and I don't have any S3 card to do testing.
If you don't need that 320x200 graphics mode (you need only text and maybe some other graphics modes) you can try some of the VGA to TV drivers. Some of the work on some of the card and some don't. I have received that scart.com and Game Zapper drivers are the ones which work best.
I have put quite an amout of time to try to figure out the S3 card problems and solution to them without any success. The further devellopment of S3 specific drivers are halted until somebody can supply enough information to easy implement the needed modifications. If you are an experineced S3 chipset programmer and want to contribute to this free driver project them contact me using e-mail me for more details. If somebody can supply me the information what to write to which S3 chipset specific registers in what order to make those problematic screen modes to work I can easily add this to my VGA to TV drivers.
I don't have programmign documents for S3 chipsets
The freely available S3 programming information (VGADOC 4) is not enough to get the drivers working without lot of experimenting with S3 based card. I am not planning to invest lots of money to to buy a set of those problematic S3 based graphics cards just to test the drivers because I don't get any money for making my drivers. S3 did not consider my project to be so be support by sending me a free databook (I have sent requests for databook few times but they have not sent me anything).
Windows setup utility availablability
Card manufacturers or S3 have not traditionally provided any special monitor setup utilities for Windows and the drivers don't provide any other way to use user-defined refresh rates. Scitech Display Doctor program could have been used to set the refresh rates of quite many cards, but I have not found any way how to get the Tv frequencies with it. The newest Windoews 95 drivers directly from S3 should include new "S3 resfresh" menu which allows adjusting the rfresh rates (I have not been able to test this yet).
I have heard that Miro has some kind of special setup tool for their cards, but I have not been able to verify it's suitability for use with VGA to TV converter.
I have also received a tip ahat you can download some configurable drivers from S3 at http://www.epanorama.net/counter.php?url=http://22.214.171.124/swlib/enduser/?license=accept. I have not tried those drivers (I don't anymore have any S3 based graphics card), so I don't have information how to get those to work and if they work at all.
S3 cards and Linux Xfree86
Linux Xfree86 gives user a freedom to select the graphics card parameters quite freely. If your graphics card has a clock generator which can be programmed to wide range of requemcies, you might be able to figure out the correct Xfree86 settings for your card. For more information look at my Xfree86 to TV page.
Help is needed for making working drivers
Somebody reading has interrests to write free drivers for S3 cards, then contact me. I can supply a working (work with many other chipsets) driver source code and you would only have to add the necessary S3 specific stuff (you have to first find out what this is).
Links to S3 information and utilities
Tomi Engdahl <Tomi.Engdahl@iki.fi>