No, you don't need any extra drivers for DOS. For mismatched cards, however...

http://falconfly.3dfx.pl/voodoo2.htm

kitten.may.cry wrote on 2022-06-11, 09:01:

No, you don't need any extra drivers for DOS. For mismatched cards, however...

http://falconfly.3dfx.pl/voodoo2.htm

A modified GLIDE2X.OVL would be actually needed for mismatched cards and I haven't seen a third party GLIDE2X.OVL file that works on a real Voodoo card.

Technically a new one can be compiled from here (which has improvements including mismatched SLI support), but it would writing a glide2x Watcom makefile which generates a DOS/4G dynamic library (and the required files for that aren't freely available).

I don't think there's any DOS 3Dfx game that can run at 1024x768 or take advantage of the second V2, so it shouldn't really matter whether or not you're using mismatched cards in this case.

The Voodoo2's GLIDE2X.OVL supports SLI and can be disabled by typing SET SSTV2_SLIDETECT=0 prior running a DOS game that uses the Glide API without having to remove the second Voodoo2 card. That environment variable in DOS can be removed by simply typing SET SSTV2_SLIDETECT=.

Huh, the more you know. I wonder if there exists any DOS 3Dfx game where the second card can increase performance provided the CPU can feed it data fast enough. I think there were maybe a couple games that allowed 800x600 support, but even that was very uncommon as most games targeted Voodoo 1.

It might prove beneficial for Q2DOS though.

Thanks everyone for their help!
I see I have the SLIDETECT=1 at the moment and will set it to =0 because inserting and removing it every time I boot up to Win98, will frustrate me and the 2nd card a but too much.

Gmlb256 wrote on 2022-06-11, 14:04:

it would writing a glide2x Watcom makefile which generates a DOS/4G dynamic library (and the required files for that aren't freely available).

OpenWatcom might be of some help though.

Azarien wrote on 2022-06-12, 10:02:

Gmlb256 wrote on 2022-06-11, 14:04:

it would writing a glide2x Watcom makefile which generates a DOS/4G dynamic library (and the required files for that aren't freely available).

OpenWatcom might be of some help though.

The compiler isn't the problem, it is the libraries required to build the DOS/4G dynamic library which OpenWatcom doesn't come with. 🙁