On 12/08/2013 04:08 AM, Paxton Hoag wrote: Floppy, 2x serial and parallel I/O I think, going by the ICs immediately around each connector. Just below those appears to be a Z80 CPU, although how it's used (e.g. simply to control I/O, or to monitor the other processor cards) I have no idea. A quick google for Action Computer Enterprise showed a linkedin page and facebook group, amongst other things, so I'm surprised that there aren't a few folks around who can answer specifics (and note the "Discovery 500" system which seems to have built-in drives - so I assume the OP's system is designed to work with an external drive cabinet). I'm curious about the large connectors (60-way?) - are those interconnects to other cards which aren't in the photos, or something else entirely? (I assume the machine has a solid backplane, i.e. it's not like an RML380Z where the system bus runs over IDC connectors/cable?) cheers Jules