Here's an auction for a Supermac expansion board for the 128K/512K Mac. It appears to have a connector which the seller describes as an expansion slot, however, it appears to be more of a SCSI hard drive connector. The copyright on the board is 1986 after the introduction of the Plus ROMs. Since the board appears to require a CPU socket to be attached to the motherboard, this upgrade likely required professional installation. However, did this upgrade board require the ROMs be upgraded too? Or did it use the original 64K ROMs (in which case the board implements its own SCSI compatible with the old ROMs)? Anybody know anything about these boards?