Radeon X1900 XT

Hello,
I was very foolish when I decided to upgrade my Mac Pro without researching the compatibility of my upgrades. I (foolishly) assumed my ATI Radeon X1900 XT 512MB card was automatically compatible. I realize now, that I may be wrong. I haven't received it yet, and am making another assumption it isn't going to work. However, I do know that it was taken out of a Gateway computer and so i believe it is BIOS instead of EFI. I am just learning about this stuff and so don't know what I am doing. I would greatly appreciate any help I can get toward learning how to flash my video card to work on my new Mac Pro. Thanks

Here is the primary link for flashing the X1900 XT

http://www.tenthousandpercent.com/?section=other&article=76

http://forums.macrumors.com/archive/index.php/t-261093.html

However, if you do not have a fair amount of experience both in building your own systems, nor familiar with flashing, I would NOT recommend this as your first experiment into flashing a board. Personally do not use any flash methods I find on internet without first verifying that others have indeed been successful. A bad flash can permanently damage the card.

Some forums to check out
extremeoverclocking.com
strangedogs
hardmac
anandtech