Maybe drivers, then? Older versions of the drivers might do the trick.
Methinks my video card may be a bit too new. As for drivers for other video cards, like Voodoo 3/4/5, I'm afraid to do that given my money situation and the fact that my video card may go "thhbbt!"

Strangely, I have a friend that can run the game in Direct3D using his modern PC. I think he even has a GeForce card not that much older than mine, but he tells me he didn't do anything special.