Display problem on Linux

I’m using Cyrix 233

Display Card : Cyrix XpressGRAPHICS(TM)
Video RAM : 2560 KB

Monitor : Videocom DCM-1488(Analog)

(it only supports 640*480(16,256,16bit) & 800*600(16,256,16bit))

But i can’t configure it in Redhat Linux 7.1.what should i do?
If anyone knows,how to configure it by using XConfigurator,
or u know any Display card and Monitor which is working same like mine