Michael,
If the graphics board is not supported by the Vibrant Video drivers you have
two options.
1) There are new Vibrant drivers that I believe you can download here, then
your card may be supported.
or
2) You can install the DOS VESA driver for your card to add 256 support. Then
in 3DS_VIBCFG set the displays to VESA (your resolution) x 256.
Shaun