In this hackintosh tutorial find out how to install ATI Radeon X1800 xl 256mb Graphic card to OSX 10.6.3 Snow Leopard ( iAtkos s3 ) 32bit ( 64bit not tested ).
First step: Download this ATI kexts to your computer.
Second step: Edit Library/Preferences/SystemConfiguration/com.apple.Boot.plist file.
To do this first copy com.apple.Boot.plist to your desktop (now you are able to edit the file), open it with text editor and than add this string.
Save file and copy it from desktop back to Library/Preferences/SystemConfiguration/ and replace the old plist file.
This method will work on many cards, third step is only for ATI x1800 card.
Third step: Copy ATI1900Controller.kext and ATIRadeonX1000.kext you downloaded earlier to System/Library/Extensions and replace the old files if exist.
Run Kext utility to fix permissions and reboot, if kernel panic, reboot and try again ( if not working ).
Now your card should be fully functional, QE/CI Enabled, with high resolution…