For people interested in building/repairing S-100 systems Andrew at N8VEM and I at S100Computers.com have just completed a prototype of a new S-100 Serial IO Board utilizing a Zilog Z85C30 UART. The board also has a V-Stamp voice synthesizer and DLP USB port controller and two parallel ports (8255).
If you would like to read about this board please look here:-
There is a growing list of people getting interested in these S-100 systems. We get these bare boards produced in batches (typically $20-40, depending on demand). So if you would like to be kept in the loop as this board evolves you need to contact Andrew or me.