Hi elunatix,

I got my 4870 working by:

-adding my my graphics card's device ID to the ATI4800Controller.kext
there are guides to show how to do this.

- using the following guide (in the link below) to add an efi string to snow leopard com.apple.boot.plist file in /Library/Preferences/SystemConfiguration/com.apple.Boot.plist

http://www.insanelymac.com/forum/ind...4&st=0&start=0

I also installed MacOSX_10.5.6_radeon_hd_48x0_drivers.pkg (you will have to google for this) but I'm not sure if that helped.

hope this helps.

cheers

sam