Well, if they'd tried to keep the same general layout, I don't think EIS, floating point, etc would have all fit in 16 bits. Maybe they should have made it a 18-bit machine? ;-) But I keep circling back to the observation that the -11 architecture's incredible flexibility/complexity ratio happened precisely _because_ it had to be crammed into 16 bits (along with a big dollop of genius :-). Given that I think the big challenge of the next generation of computer science is going to be managing complexity, it's too bad we don't teach more young CS students the -11 and UnixV6 - to show them just how much you _can_ do, with how _little_, if you put your mind to it. No, I agree with you 100%. Plenty of PDP-11 OS's did not support them. Noel