Ethan Dicks said: I just found this thread. This is a great idea and should have been tried sooner. I'll buy one. The only thing I see missing is the expansion bus connector. (Did I miss that part?) There are hundreds of things that would be nice to have, but it's important that the design be finished and the boards made. Leave the bells and whistles to the end users. If you create an Elf that can address about 2K, has a small prototype area, and has a good expansion bus, then all things are possible. (Including S-100 interface) You should copy one of the two Super Elf buses. A prototype area should be for wirewrapping. I don't see any need for plated-through holes, and pads are not REALLY necessary either. The 1861 should be easy to add on later. In the prototype area or hot melted to the top of another chip. Just make sure it's easy to cut the trace for the original clock circuit and wire in the new one. I think there is a source code listing in Paul Moews book on Elf interpreters. ========================================= Doug Coward Press Start Inc. Sunnyvale,CA =========================================