ENIAC ....

On 2011 Jan 23, at 6:40 AM, Evan Koblentz wrote: I think you still miss the point. Your text now reads: "It?s true that the ABC used vacuum tubes for logic, but that concept was already established in other inventions such as ray counters." Just changing the one word does not account for it. 'Ray counters', if we are talking the same thing, were flip-flops chained into a typical digital counter. Atanasoff's development was to take the notion of performing binary arithmetic in terms of logic gates, not in terms of counting and not implemented in flip-flops and counters, and implement that logic in electronics. (To what degree he actually conceptualised it in _formal_ logic terms, I don't know.) Yes, there were electronic 'coincidence' gates before Atanasoff and the ray counters may have used them for gating pulses into the counter, but there is a fundamental difference between what Atanasoff did and 'ray counters'. An interesting point here is that the ENIAC did not use that concept, instead taking the more-conventional-for-the-time approach of flip-flop-based counters, and it wasn't until the DR on the EDVAC that the logic concept re-emerged, and the EDVAC looked more like the ABC in that they were both bit-serial separated-memory-and-logic machines. You also continue to write further down the page: "because it used vacuum tubes for counting"