Arduino Computers & Mobile Technology
From typewriter to teleprinter
typewriter_printer.jpg

Spotted in the MAKE Flickr pool:

Flickr user numist had a typerwriter that he wasn’t using anymore, so he converted it into a teleprinter. What’s that? It turns out that teleprinters are basically a printer and a keyboard put together in a single device, but not directly connected. Instead, both are connected to a remote computer using a serial connection. When you type on the keyboard, it gets interpreted by the computer, which then prints a response on the printer. They probably don’t make much sense anymore, but before electronic displays were readily available, these were one of the main ways of programming mainframe computers.

To make his version, numist took an old electronic typewriter, and added some electronics between the keyboard and printer board. He used an Arduino microcontroller to read in each key press and relay it back over a serial port to his PC. When it receives characters back from the PC, the microcontroller emulates the keyboard to feed them into the original typewriter circuitry, causing the typewriter to print. Now, I’m not entirely sure what one could do with such a modernized typewriter, but I’ll bet there are lots of potential projects there. Got any ideas?

11 thoughts on “From typewriter to teleprinter

  1. This would be very neat if you could transmit over the internet. Then you could install a 2-way “chat” with real paper and ink. It would be even better if the typewriters used their original keyboards and printed both parties’ input.

  2. RSS feed printout seems like a given, but who’d want to waste so much paper? Need to find some ink that fades over time, then rig up some mobius strip paper feed system. Maybe a water soluble ink, then have the paper strip (or rather something water resistant) feed through a trough of water before returning to be reused?

  3. Can’t we see more perspective added to posts before they go up? To often I’m seeing posts that act like everything was invented just now.

    Starting shortly after WWII, surplus Teletype machines were available (though phone companies and military surplus) and thus amateur radio Teletype came about. The keyboard was used on transmit, the printer used on receive.

    In 1975, if you were lucky you had a Teletype machine around, or could get one cheap, because then you’d have a terminal for your new home computer, but unlike the glass terminals, you also had a printer (which were otherwise expensive). Indeed, many people had a chance at using a computer before there were home computers via a Teletype machine at the local high school or wherever that connected via a phone line t a timesharing mainframe.

    Right from the start of the home computer era, there were various schemes to convert Selectric typewriters into printers. The Selectrics were desirable since you could change the type ball, and interface wise you needed to control only a few points. There were articles about converting more mainstream electric typewriters, but that usually required controlling each of the keys on the keyboard separately. probably someone even did that before the era of home computers, since a printer was desirable. I can almost picture such a project in “QST” in the sixties.

    Slowly home computers had built in video interfaces, and then the price f printers came down. My second printer, in 1984, was a Smith Corona daisywheel, which did seem to be an electric typewriter with the keyboard chopped off. (You could get Teletype machines without the keyboard, they were “read only”).

    There was even a period of time that followed where electronic typewriters were available, with small LCD displays, and some even included an RS-232 interface so you could connect it to your computer as a printer.

    So novel as this project may seem, there actually was a time when it wasn’t uncommon, and actually served an important purpose.

    Michael

    1. Yep, that was my first “personal computer” – an ASR33 with 110 baud acoustic coupler sitting in the living room. A few years later, it was replaced by a work-supplied suitcase teleprinter with a blistering 300 baud coupler…

      And here we are, coming full circle, with many users switching to local user interfaces to remote computing resources, in the “Cloud”! Now I can use my desktop PC, laptop, netbook, or iPhone, all in multiple modes covering completely local work to “dumb terminal” to virtual machines on remote servers. At least the data rate has improved substantially!

    2. Hi Michael,

      Thanks for your sharing your knowledge about teleprinters, it’s a fascinating topic. I’m not sure what you meant by presenting this as a new thing- I’ve read and re-read my post, and can’t see where I might have implied that. We try to add as much perspective as we can, however we cover a large range of topics in only a short amount of time. For instance, I actually had to look up what a teleprinter was to write this article- I grew up in the era of the personal computer, so this is new stuff to me. We do what we can, and it is great when knowledgeable people such as yourself chime in with firsthand knowledge.

  4. What’s it useful for? Well that’s easy! Simply set up an identical typewriter in an alternate universe, and you can communicate with people there.

    Yes, I’m a Fringe fan…

  5. Amateur radio operators regularly use text modes over the air. Traditionally, these used teletype keyboards from military or industrial surplus sources. Of course, these days most hams use personal computers for the text modes, but a hard core (lunatic fringe?) of hams still like to text each other the old school way. A setup like this could capture the same feel without having to scrounge up a working teletype machine.

  6. My college job was repairing the ASR-33 Teletypes used for timesharing. I used to be able to strip them down and rebuild them.

    I still have a ex-military TT-253 typing reperforator in my basement, waiting for me to complete the interface that will make it run again.

    Teletypes are true marvels of engineering evolution. Starting with the telegraph in the 1830s, evolving from pen recorders to the first stock tickers and finally to the teleprinter, they are the culmination of years of experiments and design for reliability and (relative) speed. All wiped out by the arrival of the DECwriter dot matrix printer and the “glass Teletype” CRT terminal in the early 80s.

    Teletypes, by the way, come in two varieties: the Military and “Telex”; which use the 5 bit Murray or Baudot code, and the more modern Model 33, 35, 38 and 40, which use the ASCII 8-bit code. Hams tended to use the 5-bit machines, because they were plentiful and cheap as the industry moved to the ASCII machines in the 60s and 70s.

  7. Yeah There is a need . My wife is looking for something to print through multiple copy’s (5or 6) what she uses now are metal plates similar to a credit card with raised letters similar to metal Dog Tags ,which is rolled through like they were in Gas Stations ETC each form has to be done separately and each tag found in a file cabinet of sorts, she asked me to find a solution where it could be done from her computer So if any of you know of a purchasable product please E-mail me with product information mpainter49@yahoo.com

  8. I’d rather start with an IBM Mag Card or Mag Tape rosier. The keyboard transmit block is simple to jack onto an interface, and the carriage return just needs to drive a solenoid.

  9. Teletype machines can be used for ham radio projects. There’s probably a way to interface the makeshift TTY, computer, and radio antenna for an older feel.

    “RTTY (radio teletype) is the original keyboard to
    keyboard mode, based on the 5-bit Baudot code, began with mechanical
    Teletypes as mentioned above. It is still a popular communications
    mode, but now uses PCs for coding and decoding, using 170 Hz frequency
    shift keying at a 45.45 baud rate — 60 words per minute.”

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