XFree86 4.3 FreeBSD 4.8 ATI Rage Mobility P Inspiron 7500

[$mage]

Has anyone been able to get X to function properly. My LCD is 15.1 1024x768.
My video adapter has 8192KB. I have been trying to use the ATI Mach64 which
was in a few articles ive seen. However I always get can not open /dev/io
and server fails. I also tried XFree86 -configure but results are the same.
Is there someone who has had success with Inspiron 7500. I also have
gathered with LCDs you dont specify Horizontal and Vertical Sync Ranges. Can
someone clarify this for me. Also is it possible that I need to specify
specific Modelines in the config to bring X up. I want to apoligize for
making this so complex, but I have been hacking away at this for a couple of
months. Any help from the gurus out there would be great. This has been
quite a frustrating battle.
Thank you to all.
-smage