TTL 7400's Available

On 2 Jan 2007 at 0:23, Brent Hilpert wrote: There was at least one production parametron-based computer: http://archive.computerhistory.org/resources/text/NEC/NEC.1103.1958102 646285.pdf Vacuum-tube logic circuits with AC coupling weren't uncommon (e.g your typical instrumentation ring counter), but I was wondering if AC logic ever made it into a production semiconductor system. The parametron subject came up again when Josephson junctions were hot. (ouch!): http://www.amazon.com/Quantum-Flux-Parametron-Superconducting- Supercomputers/dp/9810204590 Apparently, it's one of those things that is periodically "invented": http://ceng.usc.edu/~bkrishna/research/papers/RAWCON98_ghzdigital.pdf It probably wouldn't do to write the authors and tell them that the basis for their patents is more than 40 years old. When I've done that (e.g., "Did you know that your work was discussed in a paper courtesy seems to go out the window. But the idea's the same, using passively-combined microwave signals whose logic value is dictated by phase. Sometimes it seems that much of human innovation is just a rehash of old ideas that failed when the time just wasn't right. I believe that the same book that discussed microwave logic also talked about storing bits in a bottle of water using some sort of nuclear spin technique. About the only thing I recall is that it involved timed reversals of an external memory field and that reading back the stored bits was a real chore. Cheers, Chuck