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 Z80 Board. The board is capable of reaching up to10MHz in a system with an active terminated bus. It also can address up to 1M of address space with 16K windows useful for CPM+.
If you would like to read about this board please look here:-
http://s100computers.com...d/Z80%20CPU%20Board.htm 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.