I think the problem is that it's impossible to find a singe and _undisputed_ definition for any of the terms above. Even computer isn't clear at all (just remember Raul Rojas' speak about the Z1), not to mention this when is a microprocessor a microprocessor discusion going thruout the list. Same for me, but if we follow the ongoing thread, it will be visible, thats it's less about whats the first of wich ever (unclear) kind, and more about vague concepts and the impact of a certain design. All this firsts and this-but-not-that things operate at borderlines where are no real borders. Maybe there is a 'Uncertainty Principle' of certain 'seem to be exact' terms. Like ordinary physiks, they are usable for every day life, but when (we are) try to define the very finest structur, we have to discover that they are no more usable. Gruss H. BTW: should I call it Frankes Uncertainty Principle of Computer Terms ? (SCNR *g*) (I meet Werner Heisenberg once in 1972 at a speech at our school - quite an notable man.) P.S.: I like Sam's point about regarding unpretended tasks AND is like Doug's idea about (technical/comercial) impact. Both have their advantages and disadvantages, but none can either be used as this blade everybody wants to have, since there is no strict this-or-that. I think both are to be considered. A concept without without follow up is not relevant, and if we only look for the (comercial) impact, so anything beside the x86 wouldn't be woth to be remembered ??? The true worth of this list is NOT to get this-or-that thing, it's about aquiering and enhance knowledge on all regarding fields, ideas, concepts, etc. -- Ich denke, also bin ich, also gut HRK