[GreenKeys] Baudot's machines
John W9DDD
w9ddd at tapr.org
Sun Nov 21 19:59:04 EST 2021
I as wondering how they measured in synch? No oscopes back then. Maybe some sort of range finder and tune for best copy? But different test signal for each channel?
John, W9DDD
> On Nov 21, 2021, at 2:39 PM, Duncan Brown <duncanancy at earthlink.net> wrote:
>
> Thanks to Tom for the history lesson!
>
> For extra credit, how where the multiplex distributors kept in synchronization? What was used for a frequency standard in the 1880s?
>
> 73
> Duncan
> K2OEQ
>
>> On 21-Nov-21 16:48, Tom Hunter wrote:
>> Jim,
>>
>> The Baudot system (1874) was inherently time division multiplex. He used four five-key keyboards. They were sequentially connected to the line by a distributor. A synchronised receiving distributor separated them and sent each to its own printer.
>>
>> In 1901 Donald Murry Developed the code we use today.
>>
>> The start-stop system was not invented until 1907 by C.L. Krumm and H. Krumm and eventually Teletype Corporation was born.
>>
>> Download navships 0967-255-0010 from Nick England's site. You will learn more than you ever wanted know about Teletypes. It is fascinating reading.
>>
>>
>> Tom N3CRK
>>
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>
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