Fixed Frequency Monitor

[dfhhr]

I have successfully managed to hook up a SUN GDM 1962 B fixed frequency monitor to my Mystique 220. Everything works fine with Windows 98 drivers. With the appropriate settings the monitor works with all Windows resolutions from 640x480 up to 1280x1024 at a horizontal frequency of 61 kHz and 72 kHz.

This shows that (in theory) the monitor should also work with DOS resolutions (VGA text, 640x400, ...). To make the monitor actually work in DOS mode I suppose that I have to somehow patch the VGA BIOS.

According to my tests it will be necessary to set the horizontal frequency to 61 kHz and keep the vertical frequency below approx. 86 Hz.

Does anybody know how to make the required patches? Any suggestions are highly appreciated.

[Kruzin]

You might be able to do something with old Windows 3.1 drivers. In those drivers, there should be a DOS TSR included(MGASET or something if I recall correctly) that might be able to do what you need.

http://matrox.com/mga/support/drivers/latest/prev_latest.cfm

[dfhhr]

No chance.

"This installation utility is designed for Windows 3.1 only"

[Kruzin]

OK...maybe I was thinking wrong. It's been a while
Try downloading the latest BIOS (setup351).
There are a couple DOS utils/TSRs in there...check the readme included with the package...

[dfhhr]

That's what I did first. But I did not find any reference to DOS text mode there. If it supports DOS text mode it will still not show BIOS startup screens since it will be loaded later. But surely this would be helpful since it would e. g. support DOS full screen mode in Windows.

I still think that it would be the most effective way if I manage to patch the video BIOS - if I get the information about the video BIOS tables or data structures that should be patched.

[Kruzin]

You might find some useful info about Matrox BIOSes at GBM's site, and possibly some utils that could be helpful...

http://grafi.ii.pw.edu.pl/gbm/matrox/