[GreenKeys] Precise baud timing

[Harold Hallikainen]

On Wed, November 12, 2025 10:41 am, Jim Cooper wrote:
> On 12 Nov 2025 at 9:45, Harold Hallikainen via GreenKeys
> wrote:
>
>
>> However, if the printer loses sync,
>> it seems like the 31 ms stop bit allows the printer to resync more quickly
>> than a 22 ms stop bit.
>
> Exactly right.   The 22ms stop bit was
> mostly used by Western Union, who figured it would increase data throughput
> by a significant percentage on heavily used circuits.
>
> The longer stop bit assures that the shaft comes
> to a rotational stop and WAITS for the next start bit.
>
> w2jc

Thanks! With a 22 ms stop bit, I'd expect the shaft to stop rotating and
wait 11 ms to start rotating on the next start bit. If the stop bit is 31
ms, I think the shaft would wait 20 ms before starting rotation again on
the leading edge of the next start bit. Of course, when hand typing, the
"stop bit" can be any length of at least 22 ms.

Harold
https://w6iwi.org



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