Use the "s3virge" driver in your Xorg.conf file (should be automatically detected and set up in any decent linux distro).
The Windows XP driver seems to be very hard to find, but it is still on the manufacturer's website for now - 
http://ranger.s3graphics.com/swlib/362drv/ and you want the "53005.ZIP" file designed for win2000 (works with xp).
No page links to 8a13.
