[GreenKeys] Fwd: How the Baudot encoding was selected

Duncan Brown duncanancy at earthlink.net
Wed Dec 21 21:18:16 EST 2022


Joe,

I had forgotten that Morkrum had there own 5-bit code.  I have a 
code-card for them somewhere.

Is your  "Morkrum Printing Telegraph" machine    a predecessor of the 
2B?  Pictures?

Duncan


On 21-Dec-22 18:30, Joe Duszyński wrote:
> And to add to the Baudot 5bit, Murray 5bit there is also Morkrum 5bit
> code. This was the Morkrum Printing Telegraph "Blue code".
> It is completely different from Baudot or Murray; code it was
> specifically created to "reduce wear and tear" as the print head
> did not use a QWERTYUIOP  arrangement, it used the DHIATENSOR
> arrangement and it is probably where the confusion is...
> I'm currently playing with a Postal Telegraph "Morkrum Printing
> Telegraph" machine it is literally one of Teletype Corp's predecessor
> machines.
> Before Teletype, before Morkrum-Kleinschmidt.
> The Western Union "Green Code" machines are more common (They use a
> Murray ITA-2 variant)
> The type head and code bars in the green code machine are totally
> different from the Blue Code machine but basic operation wise they are
> identical.
>
> JD
>
> On Wed, Dec 21, 2022 at 6:06 PM Duncan Brown <duncanancy at earthlink.net> wrote:
>> The original "Baudot" code character assignment was quite different from the IAT-2 code we know and use. Baudot designed his 5-bit code to be easy to learn, since it had to be entered (on the 5-key keyboard) by hand.
>>
>> Here is a c1900 keyboard & printer manufactured in France and derived from Baudot's c1880s patent.
>>
>>
>>
>>
>> In about 1900, Donald Murray patented a typewriter-style keyboard that punched a five-bit pattern into a paper tape. He used Baudot's idea of a 5-bit code, but reassigned characters so that the most-used characters caused the least strain on the machines. He also envisioned reperforators and page printers and added the commands for Line Feed and Carriage Return that were not in Baudot's original code.
>>
>> So when we talk about mid 20th century teleprinters using the "Baudot code", we are only referring to a 5-bit code.  It would be more accurate to refer to it as the "Murray code."
>>
>> Have fun,
>>
>> Duncan Brown, K2OEQ
>> USASA    31J30
>>
>> i-Telex: 212503
>>
>> Antique Wireless Assoc. Museum,
>>    Asst. Curator, Commercial Equipment
>> (also chief TTY op & repairman)
>>
>> www.antiquewireless.org
>>
>>
>>
>> On 21-Dec-22 17:32, Michael Katzmann wrote:
>>
>> Yes Dave I've heard this too but I think it might be apocryphal.
>> https://www.historyofinformation.com/detail.php?entryid=3496#:~:text=%22Baudot%20invented%20his%20original%20code,and%20Wilhelm%20Weber%20in%201834.
>>
>> "Baudot's original code was adapted to be sent from a manual keyboard, and no teleprinter equipment was ever constructed that used it in its original form. The code was entered on a keyboard which had just five piano type keys, operated with two fingers of the left hand and three fingers of the right hand. Once the keys had been pressed they were locked down until mechanical contacts in a distributor unit passed over the sector connected to that particular keyboard, when the keyboard was unlocked ready for the next character to be entered, with an audible click (known as the "cadence signal") to warn the operator. Operators had to maintain a steady rhythm, and the usual speed of operation was 30 words per minute."
>>
>> I think a more plausible explanation is that it's faster to press one key for common letters than multiple keys.
>>
>> Michael
>>
>> On Wed, Dec 21, 2022 at 5:11 PM Dave Horsfall <dave at horsfall.org> wrote:
>>> Probably old hat here, but apparently the hole patterns were selected so
>>> that the most common letters had the fewest punches.  A tape fragility
>>> issue, or wear and tear on the punches etc?
>>>
>>> -- Dave
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>>
>> --
>>     |\      _,,,---,,_             Michael Katzmann
>>     /,`.-'`'    -.  ;-;;,_         NV3Z / VK2BEA / G4NYV
>>    |,4-  ) )-,_. ,\ (  `'-'
>>   '---''(_/--'  `-'\_)
>>
>>
>>
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>> 1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html
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>>
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>>>>> Jordan Spencer Cunningham's GreenKeys Search Tool: https://teletype.net/gksearch
>>>>> 2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/
>>>>> 1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html
>>>>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html
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