Stack machines ARE fast! (was Re: Stack Machines)

With that proviso in mind you have an almost self-fulfilling assertion. Function calls in the modern sense (allowing recursion and re-entrancy) can either be handled by a genuine stack (as in "stack machine") or an emulated stack - and the latter has a virtual certainty of being slower. In the older sense where fixed locations and self-modifying-code was acceptable (eg in the CDC6600 and most pre-PDP-11 minicomputers) then a stack was either slower (because emulated) or required more CPU logic (and thus cost more). The B5500 was indeed a very potent machine of its era ... it was also an extremely expensive one. Nowadays any "reasonable" amount of CPU logic essentially costs the same and thus stacks are "free" ... unless, perhaps, you are trying to do something like the EIS on the big GE/Honeywell machines. "Now those four boards are the main CPU including floating point ... and those additional 9 boards are the EIS which is essentially hardware COBOL". (Although EIS also extended the range of address modes to a more complex set than I have seen in any other machine prior or later - the VAX had nothing like the range) Incidently old COBOL programs were notable for the almost complete absence of function calls - and I bet many "dusty decks" from 30 years ago are still being run daily with few significant modifications. I was going to stay out of this "discussion", but felt that a little light might moderate some of the heat. (However, I doubt it :-( Andy