There are ATI drivers in the kernel itself. Also, you can find linux
drivers on the ATI servers (though not opensource). I am working with
an ATI Radeon Xpress 200M right now using the kernel drivers. You
probably just need to tweak your x config files. Try using xorgconfig
to get a basic working xorg.conf file then use xorgcfg to be able to
tweak it.
Hope this helps =]
daeglo
"ABSENCE OF ANY INDICATED DEFICIENCY DOES NOT MEAN THAT NONE EXIST."