the group seem to point towards 6809 or IMS6100 for the processor, so now I'm looking at representative designs to springboard from (first project). Found several online 6809 designs, but only one 6100 (at www.sparetimegizmos.com) Are there any good print resources on these? (other than the bitsavers/manx resources on PDP-8 and DECmates)? (I have datasheets)=0D=0A=0D=0A When you say print resources be more specific about what you looking for. I'm sure the info is available. Check out Dave Dunfields 6809 portable page at: www.parse.com/~ddunfield/museum A very buildable and straightforward design. With a simulator as well and software that is interesting. I'm doing a varient on this one as the CUBIX OS is refreshing and fairly well documented. The sim allowed me to play with 6809 and the OS on the PC. Now if you've been to Bob's page www.sparetimegizmos.com then also check out a PDP-8 sim (win-8). The STG design is a really nice one as it really does the console as DEC PDP-8 complient rather than decmateII/III flavor. Makes a difference when your running paper tape software. [yes i know you can patch it but.. why if you dont have to.] There is a third choice the 1802 aka COSMAC or more common as the ELF. There are sims for that too. There are other CPUs like 8085, Z80 and relatives with sims around for them. Never minding 6800 and 6502s. So its a matter of taste. In all cases having a sim for the target machine will make design work and software more real and less dreaming. Allison