** NVIDIA Geforce GTX880M Mac Edition ROM **
** NVIDIA Geforce GTX870M Mac Edition ROM **
** NVIDIA Geforce GTX860M Mac Edition ROM **
Genuine Native Boot Screen & Brightness Control
View attachment 942200
Pre-installation Requirements:
- iMac12,2 (27-inch Mid 2011) Mac-942B59F58194171B (Tested machine)
- BootROM:
87.0.0.0.0. Please use High Sierra to update your BootROM to latest version.
- One of the following GPUs:
NVIDIA GeForce GTX 880M
N15E-GX-A2, MXM-B (3.0)
8GB VRAM
NVIDIA GeForce GTX 870M
N15E-GT-A2, MXM-B (3.0)
non-functional cards/original_ROMs:
80.04.EF.00.A2 (MSI)
80.04.F7.00.0C (MSI)
NVIDIA GeForce GTX 860M
Kepler (GK104) N15P-GX-B-A2
Base ROMs:
80.04.F5.00.06
80.04.E8.00.0D
80.04.E9.00.03
Maxwell (GM107) N15P-GX-A1? -
non-function with MacOS; cannot trust sources with GPU Variant
Base ROMs:
82.07.24.00.19
82.07.34.00.03
82.07.34.00.08
82.07.49.00.05
The GTX880M is the first
8GB VRAM card to work in our machines! I now have as much vram as system ram. I'm happy to report that macOS sees all the ram. It is boosting fully even at base clock speeds. When I purchased this card, the rivets were very long and kept too much of the GPU away from the heatsink surface. It was thermal throttling early as it sensed an overheat situation. When I removed the rivets, and used screws to secure it, I was able to get a much tighter seal and the card boosted properly.
Tested on a 2011 iMac using High Sierra 10.13.6. Please feel free to test on other MacOS versions, I will update this post as necessary with success/failures.
- These ROMs do not require a 3rd party bootloader like OpenCore.
- They will require a modification of the base AppleIntelPanelA/ApplePanels/F10Ta007 brightness stepping.
- The frame-buffer depth issues remains for now, and can be temporarily corrected by entering a sleep cycle.
As previous, these roms should bring back:
⦁ Genuine native brightness control
⦁ Genuine ‘gray’ early-boot screen (stage 1 & 2 progress bar)
⦁ Genuine macOS bootloader compliance
Post-installation Requirements:
Brightness Control Stepping Mod:
-Turn computer on, hold down Command(⌘)-R
-Choose Utilities > Terminal
-Enter:
csrutil disable
-
MacOS Catalina: requires you to make root writeable:
sudo mount -uw /
-Reboot
-Download and open 'Kext Utility v2.6.6'
-Navigate to S/L/E (System/Library/Extensions)
-Copy "AppleBacklight.kext" to Desktop
-Edit:
AppleBacklight.kext/Contents/Info.plist
-Scroll down to:
IOKitPersonalities > AppleIntelPanelA > ApplePanels
-There you find several Apple LCD profiles.
-For the iMac 2011 27" machine locate:
Code:
<key>F10Ta007</key>
<data>
ABEABgALABQAHAAnADMAPwBOAFwAZwBzAIEAkQClAL8A2wD/
</data>
-Change the <data> section to:
ABEAAgA3AF8AigCzAOsBJAFnAakB1AIJAlQCogL4A00DlgRpBGk=
-Drag your modded kext into Kext Utility, allow it correct permissions
-"Applebacklight.kext.bak" folder will be created
-Reboot
The above data pattern will allow for a wider span of steppings for the brightness control and utilizes more of the capacity of the HD3000. If you have a different machine, your panel ID can be found by going to
System Preferences > Displays > Color > Open Profile > mmod
Caveats post-install/Bugs:
-16bit resolution glitch of UGA_DRAW_PROTOCOL - temporary solution: activate a sleep cycle and return, this should now clear the issue.
**update 9/4/2020**
please note the 870M_6GB_UGA.rom is
experimental and in testing phases for those interested and have the card.
"insanely great!"
-Steve Jobs
View attachment 940773 View attachment 940774
