QUOTE(Movax @ Mar 7 2012, 02:58 AM)

You should be able to use an old bios chip from a old PC - and possibly flash it on the PC as well.
I would just like to add confirmation. This does work. I have done many.
QUOTE(Movax @ Mar 7 2012, 02:58 AM)

It may or may not let you use the xbox bios image file. If it screws up turn off the PC and try again....
Using Uniflash, you can flash any bios file, regardless of whether it is for Xbox or PC.
As an added confirmation measure: Flash the chip with the bios of your choice, and before you exit the program, use uniflash to "backup" the chip. Then open the "backup.bin" in xbtool or similar program to confirm that the bios was read from floppy/written to the chip properly.