I have an ATI Radeon HD 2600 XT in my hackintosh as well. This card works FLAWLESSLY in Leopard 10.5.X (all versions) just by adding the ATY_init.kext. I have made some SLIGHT progress in Snow Leopard, 10.6.2 and 10.6.8 but seeing as Snow Leopard is going to lose official apple support due to the release of Mountain Lion, I am looking to move forward.
The interesting point here is that from 10.6 all the way to 10.8 the process is the same on this card. In order to get ANY resolution change we have to remove or mod ATIRadeonX2000.kext. I think there is something SMALL missing from a kext or something that we're normally unable to pinpoint.
A friend of mine is running a Mac Pro (2008ish) and he has the Radeon HD 2600 that works in Snow and Lion without OpenCL but he still has QE/CI support. (He dual boots because Lion doesn't support Rosetta.) I've tried copying his kexts from his machine on both installs but it appears they're identical to the ones in hackintosh builds.
THIS means that we need something extra OR it's the card itself (firmware). I'm not sure he'd let me go as far as to borrow the ATI card itself... but I also tried to copy his card's firmware to a .rom file in DOS and it worked... but unfortunately I cannot flash it to my card since it's 128kb and my card's chip is only 64kb.
The fact that the cards are different is due to their EFI preamble before the BIOS of the video card itself. BUT the EFI preamble shouldn't be a whole extra 64kb! That's almost insane. Also his card is only 256mb where as mine is 512. I know flashing my card to different firmwares works because I'm currently running it on a Club3D firmware (it's originally a HIS/Sapphire). So basically... here's what I want to try...
Either finding and flashing a 64kb Mac Firmware for the 2600XT
OR Copying all the original kexts from Leopard 10.5.8 to 10.6.8(+) (I know it probably won't work, but it's worth a shot.)
OR Taking the crazy amount of time to scrutinize every difference between my friends (Lion) Kexts for 2600XT and my (hackintosh lion) kexts to make sure that every tiny detail and MD5 hash is the same.
Oh in THIS VERY forum a user has managed to get the 2600XT working by using a flashed rom, but the details are vague. You can read that here:
http://legacy.tonymacx86.com/viewtopic.php?f=3&t=19629
(Yeah, I know it's for SL but the process should be exactly the same for L and ML. Same mods and kext adds...)
I think that's about all I have on the topic... Hoping for a solution soon. :-/
Also...
This is a list of the most popular supported cards...
http://legacy.tonymacx86.com/wiki/index.php/Graphics_Card_Database.... find your card here and see if that will help...oh wait, i don't see it......have a nice day.
"Note: this is not an exhaustive list, and many cards are currently working besides the ones listed here."
Which is RIGHT above the list of 'supported cards'. The INCOMPLETE list. >.>
