for those having trouble with amd radeon 6xxxx cards
read this somewhere
Once you have the Mountain Lion installer created and the firmware on your motherboard up-to-date, you’ll need to fiddle with one file related to the ATI graphics card to get everything working. Open up the Terminal app and enter the following two commands:
defaults write com.apple.finder AppleShowAllFiles 1
killall Finder
This will temporarily reveal all of the hidden files on your computer. Navigate to the USB drive with the Mountain Lion installer and go to the
System/Library/Extensions folder. Locate the
ATI6000Controller.kext file,
copy it to another location on your computer, and then delete it from the flash drive. Be absolutely sure that you copied the file to a location you can access later on (like onto the installation USB drive). Enter the following commands in the Terminal app to re-hide the hidden files.
defaults write com.apple.finder AppleShowAllFiles 0
killall Finder
As your computer boots into Mountain Lion for the first time it may report errors about incompatible files, lack of network and/or audio function, and have an incorrect screen resolution. Ignore all this for the time being. Move the
ATI6000Controller.kext file you copied earlier to your Desktop and run
KextBeast to install it to the correct location (You will need to change the Gatekeeper settings in the Security Pref Pane to allow for applications downloaded from ‘Anywhere’). Restart your computer and this time do nothing at the Chimera screen. Your Hackintosh should boot normally and have the correct aspect ratio. At this point you’ll want to run
MultiBeast to fix any non-functional system functions (network, sound, 3rd-party drives, etc.). You’ll probably also want to select the Repair Permissions option to make sure that everything is correctly installed. If everything went as planned, then you should have a fully functional Hackintosh running OS X