Hot Flashing Guide Rev. 2.0 (2004)
archive.techarp.com
2 threads
I had to do this once, after a blackout during a BIOS flash bricked my motherboard. Fun stuff. I don't think the working motherboard donor knew what he was signing up for.
When I worked in the PC hardware industry, I used to do this all the time with certain machines of the small form factor variety where the chips were removable, replaceable. I still have one of those machines, e.g. Socket AM2+ compatible, though have not turned her on in over 12+ years.