Got GeForce FX5500 to work with Win98!
I finally got it working!! Hurray!!
I run a dual boot computer with two different hard drives. One has Fedora Core 6 linux and the other has Win98. The motherboard is an ASUS A7N8X, the monitor is a BenQ FP731 17" LCD and 512MB of RAM. I originally had an ATI 9200 video card and wanted to upgrade a little bit and cheaply. So the GeForce FX5500 seemed a good choice for both price and performance.
After installing the card my linux install refused to allow me to increase resolution from 800x640 and something higher and enable 3D acceleration with the nvidia drivers. It turns out that the BenQ FP731 LCD does not support EDID properly so the nvidia driver refused to allow anything higher (I suppose to protect me). I had to go into xorg.conf file and add a single line to tell nvidia to ignore EDID and use the xorg.conf settings. That worked great.
I really didn't expect any problems in win98, but guess what... I couldn't change resolution from 800x640 or get 3D acceleration to work. The nvidia configuration tools wouldn't even work. I used driver cleaners, deleted
everything I could, disabled ATIPOLL, tried manually changing registry settings changed vcache to 25% of 512MB (524288 ->131072 bytes), set BIOS AGP aperature size to 128MB, and disabling monitor plug-n-play. I just couldn't find how to get the nvidia driver to ignore EDID information. After all that it just starting magically working after one of my restarts.
What a pain. What a relief.