First off wanted to say hello. Been hanging around vogons for several months now and have found it to be quite interesting and informative.

I finally have a question I would like to ask the community about a build I am working on where I have hit a strange issue. I have a very small form factor (almost LPX type?) case with a riser card. The riser is 16 bit ISA only. I have been slowly getting parts off ebay and replacing as I can and I finally have everything but with the last piece which was a speedstar video card I have introduced an issue.

I get strange colors and it isn't bad VRAM. At POST screen the colors will be randomly off. Like the yellow energy star logo will be blue, then next reboot it will be red, then it will be fine on the next reboot, but seconds later something else will have a different color. However you also can get a screen full of jumbled color bars with lines as well at random times. This didn't happen til I put the speedstar64 ISA card in the system. I have tried both the IRQ and wait state jumper on the new video card with no change. Tried disabling all caching and set everything to fail safe type settings in AMI bios with no change either. I have found that the only way to correct this anomaly is to remove my IDE/Floppy controller from the riser. If I put the controller directly in its own slot in the mainboard the system seems normal and happy. Now this is great, but I can't normally run the controller card in a different slot unless I have the case fully disassembled since the back won't line up properly and the case won't go back together, so I am limited to using only the riser. The old trident card didn't have this issue, so I guess the speedstar is running faster or the controller won't let it work properly. I also tried it with turbo button enabled or disabled, it didn't change anything.

Has anyone heard of this type of issue? I know I have been working on PC's since the early nineties and I have never had this issue, of course 99 percent of the machines I serviced were not using risers.

Just wondering if someone thought a jumper on the mainboard might help me out or if everyone thinks I should try a different IDE controller. I don't have access to another controller to try out at the moment, as I would have to get one on ebay. At all the places I work for, I can't seem to find anything older than a Pentium 4 775 LGA. Old hardware is hard to come by in these parts...

The specs..
Genuine Intel 486DX 33MHz
V4P895P3 SMT /V1.0 socket 3 mainboard
ISA speedstar64 Video card /w 2MB
ISA UN1075GT Controller (winbond w83758p + w83757F)
ISA Creative SoundBlaster 16 (removed altogether for testing purposes)

Thanks for any input anyone has.