maybe help you
Ok people, this is a reply to you & any other person that wants to follow my method and see what can come out of it...
I suggest you install first modbin's X1650 package, reboot, select the desired resolution, and get ready to modify the files.
Get a Hex Editor, i suggest 0xED (Yes, this is the name of the Hex Editor Program).
Copy files "ATIRadeonX1000.kext","ATIRadeonX1000GA.plugin","ATIRadeonX1000GLDriver.bundle" from /System/Library/Extensions on your desktop.
1) Show contents of "ATIRadeonX1000.kext", go into /Contents/MacOSX and hex edit "ATIRadeonX1000" binary file. Replace *every* occurence of C071 with your Device ID (Example, my Device ID in reality is 0x71C1 so in the file i'll write it as C171). Save the modified file. In the same .kext edit "Info.plist" file with TextEdit and replace the *only* 0x71C01002 entry with yours. In my case it is 0x71C11002.
2) Show contents of "ATIRadeonX1000GA.plugin", edit "Info.plist" with TextEdit, and you will see 2 strings in the following format: 100271C0-0000-0000-0000-000a27898d3e. Again replace the 71C0 with your Device ID on both. Save the file.
3) Show contents of "ATIRadeonX1000GLDriver.bundle", hex edit the binary inside /Contents/MacOSX and replace C071 entries with your own, just like you did on step (1). Save the file.
Drag n drop those 3 files form your desktop into /System/Library/Extensions (Authenticate & Replace).
Open Terminal:
sudo -s
chmod -f 755 /System/Library/Extensions
chown root:wheel /System/Library/Extensions
diskutil repairPermissions /
reboot
