15 Oct
2007
15 Oct
'07
2:57 p.m.
On 10/14/07, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
I prefer mechanical horology, but anyway (actually, there have been
mechanical digital clocks, but I digress).
It's not that hard to provide the same fucntion using a pair of 7490s or
a 7490 + 7492 as approrpritate. Or to start from a wristwatch crystal
(32768Hz) and use a 15 stage divider.
The only 8-pin TTL chips I (just) rememebr the
7456 ands 7457 (I think)
which were /50 and /60 counters (desigend to get 1Hz clocks from European
or US power lines)
Those sound handy (since digital horology is one of my hobbies).
Never seen one, but I suspect they weren't common after, say, 1975.
I've never seen either.
-tony