ATI Radeon HD 2600 XT 512 MB (Diamond) - Mountain Lion - Video Problem

[nbpanjwa]

I'm using ATI Radeon HD 2600 XT 512 MB (Diamond) Video card with Mountain Lion installed. Everything else including Sound working fine.

 

I managed to get thru resolution 1680x1050 60Hz on DVI port using Aty_init and modified ATIRadeonX2000 kexts. I had to remove Vendor Id and Dev ID ex : (0x95881002) in ATIRadeonX2000.kext to get to the desktop without which I was hitting white screen with cursor. It seems that ATIRadeonX2000.kext is not loading. I can boot with original ATIRadeonX2000.kext but only with -v -x flags which gives me same problem, ATIRadeonX2000.kext is not loading. I think this kext needs to be edited or some other kext is needed to activate this kext. I have read more than 100 posts in last few months but could not find any solution out there.

 

Problem is that I cannot play DVD, videos in iTunes, Youtube videos, selecting new tab in Safari gives flickering screen and new notification center flickers.

 

kextstat | grep AMD

77 2 0xffffff7f814a2000 0x1ea000 0x1ea000 com.apple.kext.AMDSupport (8.0.0) <71 10 9 7 5 4 3 1>

78 0 0xffffff7f816a7000 0x49000 0x49000 com.apple.kext.AMD2600Controller (8.0.0) <77 71 10 9 5 4 3 1>

87 0 0xffffff7f8168c000 0x13000 0x13000 com.apple.kext.AMDFramebuffer (8.0.0) <77 71 10 9 7 5 4 3 1>

 

ioreg | grep AMD

| | | | +-o AMD2600Controller@? <class AMD2600Controller, id 0x10000027c, registered, matched, active, busy 0 (0 ms), retain 5>

| | | | | +-o ATY_Lamna <class AMDFramebuffer, id 0x10000028e, registered, matched, active, busy 0 (1 ms), retain 15>

| | | | | +-o AMDNDRVService <class AtiAppServices, id 0x1000002de, registered, matched, active, busy 0 (0 ms), retain 6>

| | | | | +-o ATY_Lamna <class AMDFramebuffer, id 0x100000293, registered, matched, active, busy 0 (0 ms), retain 12>

| | | | | +-o AMDNDRVService <class AtiAppServices, id 0x1000002e4, registered, matched, active, busy 0 (0 ms), retain 6>

| | | | +-o AMDSupport <class AMDSupport, id 0x10000027d, registered, matched, active, busy 0 (0 ms), retain 5>

 

I'm not willing to accept that the card is too old or cannot be used in Mountain Lion since the fact is that Mountain Lion still carries all necessary kexts for this video card. Therefore, it must work with tweaks and experts advice. I'm eager to learn and open to constructive advice.

 

I'll appreciate if anyone can help or at least guide me in right direction.