800x600 Xwindows on Linux

[Darren Marshall <darren@theplanet.net>]

Can anyone tell me if its possible (or better still forward me their
XF86Config file) to get Xwindows to run at 800x600 under Linux on a 
Thinkpad 755CX.Also is it possible to get 800x600 at the command line.
I've tried setting PS2 mode3x on and then using loadlin to boot but 
although this gives me a full width screen,the bottom 3rd of the screen 
gets corrupted...

Any ideas

Regards Daz