Using VGA to TV converter with Windows 95/98
I have only personally got my converter to work with Windows 95 systems which have had Matrox Millenium or Matrox Mystique graphics card.
General information
Using VGA to TV converter with Microsoft Windows is harder than with plain DOS. Windows has it's own display card specific drivers which setup the the screen mode and provides the video services to other Windows applications. Making Windows display to work with TV would need the Windows driver to be modified to output the signal suitable for TV. Modifying existing drivers is very hard and getting tools and knowledge to write your own Windows drivers can be even harder.
So usually you can forget getting the normal Windows screen to TV using my circuit unless the driver is configurable enough (Matrox Millenium is very good in this). Nowadays some modern drivers have quite sophisticated options for defining used defined monitors. Using this route gives the best result if the setup program can take TV display parameters. Remeber that it is not worth trying more than 640x480 resolution in TV because of resolution limitantions of TV. 480 scanlines fill the entire NTSC picture vertical area, but in PAL picture there is more resolution available (you might try also 800x600 resolution with PAL TV).
DOS full screen sessions
You can use the DOS drivers in Windows full screen DOS sessions to run DOS programs in TV screen. I have used Windows 3.1 for various VGA to TV driver tests, because I can easily switch between TV display DOS session and Windows screen in VGA monitor by just using the normal active window changing key combination ALT-ESC. This is very nice feature in this setup if you can have both TV and VGA monitor connected to VGA card at the same time (you need monitor switch or signal aplifier box for this).
Tested systems
Matrox Millenium and Mystique
Matrox Millenium has very good configurability options for those who want to experiment. With the tools provided by Matrox and sometimes minor hand editing of the configuration files (which are mostly ascii files) gives excellent results as long as you know exactly what you are doing. I have got my circuit to work very nicely with Matrox Millenium on Windows 95. I have also got the system to work quite nicely with Matrox Mystique on Windows 95. I have not tested the system on Windows 98, but I would expect this to work also on it.
Matrox Millenium is the best card to be used with my VGA to TV converter I know. I have a special page for Matrox Millenium users to give more information.
Trident and Cirrus Logic cards
According some reports I have got it is possible to make the Windows95 to work with the VGA to TV DOS drivers in standard VGA modes and in 640x480 with 256 colors mode. If you make so that those DOS drivers are loaded in your AUTOEXEC.BAT file then the Windows drivers typically make use of those because they typically use BIOS routines to initialize the screen modes. If the driver just calls the BIOS routine and does not change the screen refresh rate after that then my VGA to Tv drivers whould operate without problems.
I have received some reports that the DOS drivers work with Windows95 quite nicely atleast with some graphics cards:
- Trident 8900 has been reported with DOS drivers both in interaced and non-interlaced mode
- Cirrus Logic 5426 has been reported to work with Paulo S�rgio Coelho's vgatv.exe
IBM Aptiva with an integrated ATI 3D PRO Turbo AGP2x grahics card
This information on getting the circuit wo work with IBM Aptiva with an integrated ATI 3D PRO Turbo AGP2x grahics card and WIndows 98 is provided to me by Anders G�vner. More of this kind of success stories are wellcome.
"I have successfully made your VGA -> Scart circuit, and I must say that it totally wipes the floor. Thanks to you I have saved a fortune! I have an IBM Aptiva with an integrated ATI 3D PRO Turbo AGP2x grahics card. It took a while for me to have good pictures in windows 98 because I had to spend hours tweaking the registry. The settings weren't as user-friendly as the Matrox ones, they were rather only hex numbers. I attach two reg-files which give perfect images in both 640X480 and 800x600 so other ATI users don't have to sit as long as I did in front of the screen. In fact I spent shorter time building the circuit than tweaking the registry! Hope they will be useful."
There is a couple of things that I have to add though:
- 1: The monitor setting in screen properties must be changed to "Television" or "TV". Otherwise my settings will be forgotten every time the computer is rebooted!
- 2: The user may have to edit my registry files depending on the actual refresh rate. If you have default 60Hz the first line in the registry file must be 640x480_60 or 800x600_60.
Other ideas
There are some commercial utilities designed for Windows95/98 for setting the screen refresh rates quite freely. The following programs might or might not be useful if you want to experiment with them (I have not tested their new versions in this):
Tomi Engdahl <[email protected]>