Ok guys, the issue is resolved. It seems that the motherboard was the problem, as it completely died the next day (from reasons unknown). I got an ASUS Cubx, based on Intel 440BX with one ISA slot as the replacement, put in the exact same configuration (it's a socket 370 as well, so no problems there), and everything is working properly now. Thanks for all the advices and your time, though. 😀

I also hame a cubx board, looks solid, didn't have a chance to try it out though.

Considering the passthrough cable, the problem is definitely overhyped. In order to preserve my precious IBM CRT I use 2 passthrough cables: 1 short from host card to Voodoo, one 1.8m from Voodoo to make sure the monitor cable does not die from regular bending.

btw, my current rig has 4 videocards (usually disabled onboard S3Trio3D, TNT2, Voodoo 2 SLI) and works perfectly.

4 cards? Wow, that's nice! 😀
Well, the noticeable blur at 1280x1024 really does strain my eyes after a while, but on 640x480/800x600 there are barely any differences. And the game I've tested run flawlessly (eye straining-wise), even on high resolutions in D3D/passthrough.

It really depends on the cable a lot... I don't notice any blur at 1600x1200 in D3D, however, my monitor is only 17" and pixels can not be destinguished 😀