TTL 7400's Available
cclist at sydex.com
Tue Jan 2 12:34:25 CST 2007
On 2 Jan 2007 at 0:23, Brent Hilpert wrote:
> The parametron circuit was AC-coupled wasn't it? .. read a little >
> bit about it some years ago, but not in much depth.
There was at least one production parametron-based computer:
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
> ..haven't heard of that one before.
Apparently, it's one of those things that is periodically "invented":
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
from 1962? I can send you a copy if you'd like."), intellectual
courtesy seems to go out the window. But the idea's the same, using
passively-combined microwave signals whose logic value is dictated by
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.
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