Need higher than 8 depth for NVidia TNT2

[xs411]

I have an NVidia TNT2 M64. I am running Blackbox on SlackWare and I was wondering how to get higher than depth 8 to work on my machine. I think I might not be configuring the svga server properly. I've tried moving around the different depths, but for some reason it needs to run the default depth of 8. I want to eventually get the new NVidia installed. Any suggestions?

Thanks,
XS411