I know the 640 took a dos board, but I do not have one. Not sure on the 580 as I only have a 575. Other than the ram slot it's identical in system profiler.

Now I just need to find out if the connection on the rca/s video in board was meant for anything.

Lots of what ifs with these I just skipped over its kind of fun.

Just need some cheap full 040's and they will be all set.