I've got an AOpen PT75 II card that I tried to set up under X. It has an 86C385 chip on it. I tried S3V, SVGA and VGA16 servers, I tried autoprobing it, specifying the chipset, calling it a generic VGA, etc. In almost all cases, X windows worked fine, but when I came out of X windows to a console, the text on the console was scrambled and stayed that way. I had to type "blind" in order to shut down the machine as the console wouldn't echo properly, and that was the only way the console would fix. Only if I showed it as a generic VGA with under the VGA_16 server would it sorta work.
It appears as though if the system finds out what kind of card this really is, the card thrashes video memory. Only if I run it at its lowest capability does it mostly work (in this case, the X screen bulges outward at the sides. This is a fairly common card. I finally replaced it with an older Diamond Stealth 3D 2000. But surely someone has had success setting it up? Paul M. Foster