Toss a coin.

Meaning?.. It may or may not run on 75MHz? What does that depend on?

Nobody can answer your question with so little data. So toss a coin. If you want to troubleshoot this properly: get another board (430VX for example) and test your Voodoo I on both with 66 and 75 FSB. Another Voodoo I also would help.

The Serpent Rider wrote on 2020-04-13, 09:16:

Nobody can answer your question with so little data. So toss a coin. If you want to troubleshoot this properly: get another board (430VX for example) and test your Voodoo I on both with 66 and 75 FSB.

Apologies if it sounds like I wanted someone to troubleshoot it for me - I just wanted to know if Voodoo 1 cards were commonly problematic at out of spec PCI speeds.

It's random, but usually all Voodoo can tolerate 37 Mhz PCI. Then again, check your motherboard.

What CPU do you run on the TX board? I remember faster versions of K6 to cause troubles with Voodoo Graphics.

havli wrote on 2020-04-13, 19:07:

What CPU do you run on the TX board? I remember faster versions of K6 to cause troubles with Voodoo Graphics.

Cyrix 6x86MX PR233

Ok, that one should be on the safe side.
I don't remember if the VG issues were on only on AMD socket 7 CPUs or all non-Intel in general. Anyway, you could still try the older driver, just to make sure. It helped me to run VG properly on K6-2 400. The latest official win9x driver from 3dfx caused black screen and crash when running any 3D accelerated game. But the second latest (you can find it on the falconfly archive) worked very well on the other hand. Even when I manually copied over the latest glide 2x, 3x and OGL DLLs.

Another possibility is to swith the Cyrix to run at 3x66 for example... and check whether it helps or not.

havli wrote on 2020-04-13, 21:19:

Ok, that one should be on the safe side.
I don't remember if the VG issues were on only on AMD socket 7 CPUs or all non-Intel in general. Anyway, you could still try the older driver, just to make sure. It helped me to run VG properly on K6-2 400. The latest official win9x driver from 3dfx caused black screen and crash when running any 3D accelerated game. But the second latest (you can find it on the falconfly archive) worked very well on the other hand. Even when I manually copied over the latest glide 2x, 3x and OGL DLLs.

Another possibility is to swith the Cyrix to run at 3x66 for example... and check whether it helps or not.

Oh.. I tried various MiniGL driver versions but I did not try an earlier driver version! I will try this tonight for sure, thanks for the heads up havli!

Voodoo cards are sensitive enough to PCI bus usage even when not run out of spec. On my Sis 651 chipset, I can use a 3GHz P4 with a Voodoo as long as none of the integrated stuff on the motherboard touches the PCI bus - something that's configurable in BIOS. But if I move the USB controller or integtated audio to the PCI bus - something that's required to get a Matrox G200 not hard locking the system - then the Voodoo graphics starts crashing or showing display corruption artifacts.