There was drivers for radeon 5 series in macmini 10.6.4 image
so let's try to use them
ATI5000Controller.kext ATIRadeonX3000VADriver.bundle
ATIFramebuffer.kext ATISupport.kext
ATIRadeonX3000.kext
ATIRadeonX3000GA.plugin
ATIRadeonX3000GLDriver.bundle
so let's try to use them
ATI5000Controller.kext ATIRadeonX3000VADriver.bundle
ATIFramebuffer.kext ATISupport.kext
ATIRadeonX3000.kext
ATIRadeonX3000GA.plugin
ATIRadeonX3000GLDriver.bundle