Just finished this project and thought it would be of interest to people here. The 7800GT Mac edition card is a relatively powerful card for late-2005 G5 computers. It is also rare, like most Mac Edition cards. Additionally, it is a real chore to flash a PC 7800GT into a Mac Card. This is because the Mac ROM is larger than the PC ROM, so the Mac ROM will not fit on the EEPROM chip on the PC card. To work around this, install a larger ROM chip. To do this, you will need: Replacement thermal paste for GPU chip Replacement thermal pads for memory (I bought from this listing) Soldering iron and solder Replacement EEPROM chip For the replacement EEPROM chip, I used the Atmel AT25F1024 chip that I purchased from this (you will get 10 of these chips, which is great if you mess up). I was concerned that they might be bad fakes, but the first chip I used worked fine. This is the same chip that is used in the Mac edition 7800GT card. The PC version uses the smaller SST 25VF512 chip. Chip-quik SMD removal makes it a lot easier to desolder the PC EEPROM Here is the whole process: Create a DOS bootdisk and put nvflash 5.63 on it Use nv563 to back up the ROM on the PC card The commands to do this can be found on themacelite or by running nv563.exe (or whatever the nvflash executable is named) Having backed up the card, remove the heatsink by unscrewing the screws on the bottom The chip you will need to remove is on the left side of the card (the side with the DVI ports) Desolder this chip, taking note location of the dot on the chip Solder in the AT25F1024 chip, making sure the dot is in the same orientation. Replace thermal paste and pads Reattach heatsink Use the --check command to determine which "number" is the card to be flashed. It will probably be zero or one, depending on how many NVidia cards are found. Use the following command --index=X -4 -5 -6 -j nvmac.rom X is the number that you found using the check command. Replace nvmac.rom with the ROM you would like to flash. You can get the ROM at themacelite. The card should flash and be ready to put in a late-2005 G5 Note: I've attached pictures of the card I did this on. This procedure might not work on all cards.