A1200 power through the floppy molex connector?

[doctorq]

Well, I did. Jumped an ATX PSU and hooked it up to see if this old MB worked. It came up just fine to the ROM screen.

There is no problem in doing this, but you will have sound issues unless you hook a -5V supply to the machine.

Running the machine with only this power source with a variety of expansion might not be a clever idea.

[doctorq]

-12v is missing in this thread,not unless someone is doing something special to use -5v.

A slight misprint from my side; it's -12V, not -5V. The other post got me confused there for a second.