Sujet : Re: the early teletype
De : g4ugm (at) *nospam* dave.invalid (David Wade)
Groupes : comp.misc alt.folklore.computersDate : 15. Nov 2024, 01:34:06
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vh64tu$31ak2$1@dont-email.me>
References : 1 2 3 4 5 6
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On 14/11/2024 22:29, Lawrence D'Oliveiro wrote:
On Thu, 14 Nov 2024 22:19:48 +0000, Sn!pe wrote:
Lawrence D'Oliveiro <ldo@nz.invalid> wrote:
>
On Thu, 14 Nov 2024 18:45:48 GMT, Charlie Gibbs wrote:
>
Original Teletype machines ran at 45.45 baud.
>
I remember labels on Creed machines saying "50Bd".
>
I had a Creed 7B 60 years ago, I used it for RTTY. It had two
governers, one for 45.45 Bd, the other for 50Bd. They had white strobe
marks on the circumference to set the speed accurately.
Hmmm ... presumably the strobe marks were for use with a fluorescent
light ... driven from AC mains frequency? Did they have different marks
for 50Hz versus 60Hz mains?
No, that wouldn’t work, you would need entirely different gearing for the
strobe wheel ...
You used a tuning fork with a thin "slit" attached to each leg. The slits were arranged so they opened and closed as the fork vibrated creating a tuned shutter.
You viewed the bands on the governor through the slit and so could adjust the speed and when they were stationary the spped was correct. You had different forks for 45.5 and 50 baud. Some machines could do 75baud as well.
I found this site with some pictures and more info. There will be others...
https://www.cryptomuseum.com/telex/tools/fork/index.htmDave
G4UGM
the early teletype
Re: the early teletype