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Thread: Morse code transmitter with memory and keyboard

  1. #1
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    Default Morse code transmitter with memory and keyboard

    I must have read about this in QST or 73 more than 50 years ago, but now, I'm trying to remember the details of this particular machine.

    It consisted of a slowly rotating drum with rows of pawls, one pawl for each letter and number of the alphabet.

    If a key was pressed, a corresponding pawl would be flipped and later read mechanically to send a Morse character. Once a pawl's position had been read, it was returned to the inactive state.

    The idea was that an unskilled operator could type in a brief message and have it sent in perfectly-timed morse code.

    Does anyone recall this device? Is this one of the earliest types of read/write memory?

  2. #2

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    Sorta... But I wouldn't have been able to read about it that long ago; I must have read about it later than that.

    What defines read/write memory though? Are Hollerith cards read/write or read-only?

    If I had to guess, the mechanism in that transmitter must have been used for some kind of automated manufacturing as well, potentially making it even older. Unfortunately, the history of industrial automation is mostly lost.

    By the way, would this be considered the same as a latching relay (which must have come later)?
    Last edited by KC9UDX; August 19th, 2019 at 06:09 PM.

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    No, not a latching relay exactly. Just a bunch of pawls that can be flipped one way by the keyboard and read and reset mechanically. AFAIK, no electrical coils involved. What I can't recall is if the message was set into the drum in one step, then read out in a second step. I suspect that the whole affair could be driven by clockwork.

    Punched card is more of a read-only memory in the sense that once information is entered, it can't be erased and rewritten (practically).

    More like a combination action on an organ. You can set it up any way you want and then "read it out" and then set it up differently.

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    One example was reprinted in a blog about 10 years ago, see http://blog.modernmechanix.com/morse-code-typewriter/ A bit lacking in information and while Willard Guthoerl is mentioned in a lot of indexes, nothing I can find shows a more detailed description.

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    No, this was purely electromechanical. The drum was visible.

    [quote}Sanford Research Institute’s computer lab, Menlo Park, Calif. [/quote]

    Wonder what the folks at SRI thought of a competitor?

  6. #6

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    Well a latching relay doesn't have to be electrical. That's why I'm thinking this is the same concept. It's mechanical in stead of electrical. You could do it pneumatically or hydraulically, or by vacuum too.

    The combination organ is a good example. You can manually set and reset the stops, or you could electrically actuate them as a preset.

    I'm trying to imagine if I ever saw such an action in a screw machine. Probably not because everything can be done with cams. But this could be implemented, to reduce cam changes. The oldest things I have worked with that do this (set and reset, read and write, fully mechanically) are grinders. I don't know how long they were made this way; certainly WWI, but earlier than that I don't know.

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    I found a mention and illustration here.

    ca. 1925. You can see the drum quite clearly. There's a 1925 Pop Sci article that this was essentially copied from.

    A very long time ago, I read a very detailed description of the thing by someone who actually had hands-on experience.

    At least I now know that I'm not hallucinating.

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    Huh... Newer than I thought.

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    Found the patent--took a bit of doing, though. The fellow's name is "Edwin H. Piersen" patent 1,359,463. (1920) All I've got so for is an image of the device, but I'll keep looking.

    Here it is

    It's interesting to note the 1919 reference to "a storage element".

    One wonders if a electromechanical computation device could be worked out using this technology.
    Last edited by Chuck(G); August 20th, 2019 at 08:48 AM.

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    Curious: Do you think it employs some sort of FSK or AFSK?
    Surely not everyone was Kung-fu fighting

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