Vacuuum tube digital circuits (50 year rule)

[Ethan Dicks]

On 8/31/06, Michael Holley <swtpc6800 at comcast.net> wrote:
> I recently got a book titled High-Speed Computing Devices 1st ED. 1950...
>
> I have been adding to my magazine scans. I found a decade counter circuit
> implemented with four 12AU7 tubes (dual triodes) in the October 1955 Radio &
> Television News. (50 year rule.)
> http://www.swtpc.com/mholley/ElectronicsWorld/Oct1955/RTVN_Oct1955.htm

Cool!  I happen to have a dozen 12AU7s here in my desk - they were discarded
from the stock shelves when they cleared out "Skylab", the former home for a
wad of experiments dealing with aeronomy and auroral observation -
Carl Sassenrath of REBOL fame worked there once, many years ago).

Hmm... a decade counter with 4 tubes... with a dozen tubes, I'm
half-way to a digital clock - just add nixies!

Thanks for the pointer!

-ethan