And some didn't: The HP 2100 and the PDP-8 (and I think the Honeywell x16s), instead of a stack, would store the return address of subroutine calls in the first word of the subroutine; obviously, this made recursive subroutines impossible without handling a stack manually. Reading up on the early history of CDC, I stumbled across the "Little Character" - Seymour Cray's six-bit proof of concept for his first computer designs at CDC. Apparently, one was actually built, because it's now at the CHM. However, I haven't been able to find any significant information about this on the Web (my Google-fu must be failing me). Does anyone know where I could find some documentation about this machine? Performance specs (memory size, speed, etc.) would be nice, but I'd really like a detailed architecture and instruction set description - you know, in case someone wanted to make an emulator or something... ~~ Mark Moulding