The HellZXchreiber


Hellschreiber – German for ‘light pen’ – was developed in the 20s as a way to transmit text in a way that was much more robust than the teletypes of the time. These devices were used to great effect by the Germans in WWII, and later became popular with wire services and was used until the 80s. The fax machine then happened, and no one really cared about Hellschreiber, save for a few plucky amateur radio enthusiasts.

In the early 90s, a few of these amateur radio enthusiasts realized they could use their personal computers to communicate with this extremely simple protocol that’s also very resilient against interference and weak radio links. [Danjovic] is following in their footsteps by decoding Hellschreiber on an old ZX Spectrum clone.

[Danjovic] tested his code with the sound sample found in the Hallschreiber wiki article and some text generated by Fldigi. Everything works beautifully, an [Dan] can even change the intensity of the text with the volume control – a very useful feature should the HellZXchreiber ever make it out into the field.

Source and image files available for all you strange Speccy fans. Everyone else can check out the videos below.



23 thoughts on “The HellZXchreiber

  1. Lol, ‘Hellschreiber`’ is NOT german for ‘light pen’, it’ just the literal translation of the two words put together. ‘Hell’ was the last name of the inventor, Rudolf Hell.

  2. Even if the german “Hell” can be translated as “light”, the Hellschreiber was named after his inventor Paul Hell. So, the correct translation would be “Hell writer” (no, not “hell writer”).

  3. No jokes the Germans were and still are amazing engineers.
    Just look at how hard America had to work to build colosus to crack the lorenz cypher.
    And when WW2 was over they stupidly packed all the colosus’s into boxes.
    Even early Victorians had the chance for a mechanical computing age… but the man who wanted to build it was unstable and had bad help and was fobbed off a few times.

    The computer truly was born from blood, sweat and death.

    1. I will say they were amazing. As a person owning a modern German motorcycle, they are no longer amazing engineers but are now as incompetent as American engineers. Quality has dropped through the floor. BMW bikes from the 80’s and 90’s are 500X better designed and built than anything sold since 2010.

      1. German overengineering is legendary, and remains present in some fields (consider most Seimens hardware…). Sadly, as you’ve noticed, it’s been badly diluted by American (among others) engineering practices, and the precision for which German engineers have long been noted has been decaying badly of late. There will always be a high-level strata, but it’s becoming thinner and thinner (and thus more and more expensive to obtain)…

    2. > but the man who wanted to build it was unstable and had bad help and was fobbed off a few times.

      You clearly know nothing about Charles Babbage. Unstable? He was one of the few men in history to hold the Lucasian Professor of Mathematics! You don’t get that title by being “unstable”!

      Bad help? He had Joseph Clement as his chief machinist! This guy was arguably the top of his field at the time!

      As far as being “fobbed off” – as far as I can tell, this didn’t occur; if anyone wasted money on the projects, it was Babbage himself.

      What Babbage was – above all – was impatient. He had an idea (the Difference Engine), but quickly saw improvements for it (to generalize it), and before completing it, he came up with an improved version (the Analytical Engine). But before completing that new version, he kept improving it – never actually stopping and implementing the full version.

      The classic example of scope and feature creep all in one.

      There were also issues with Clement – which I think happened mainly because of poor contracts and miscommunication, coupled with the overall stubbornness and arrogance of both men; arguably it should have been the perfect marriage, but alas it fell apart due to various disagreements over the resulting machining technology (which helped to push forward that area of industry as well).

      I’m not sure where you got your impressions or ideas from, but you might want to review your understandings of the man and his inventions.

      1. … also helped by Ada Lovelace, the word’s first programmer. And if you want an entertaining take on the whole Babbage thing Google “2D Goggles”.

        Always wondered what the Hell was in Hellschreiber.

        1. I don’t know whether to thank you or damn you; the last thing I needed was a new and wonderful looking web comic re-imagining and exploring such topics!

          It looks wonderful, by the way… :)

          Though I keenly and thoroughly understand Ada’s own contributions, I didn’t make mention of them in my response to xeon simply because she wasn’t the subject being scrutinized…

          I’ve studied Babbage, Lady Ada, and the rest (along with a lot of Victorian history) for longer than I can recall; I am glad that you posted your comment, as I would have missed what looks to be an entertaining fictionalized treatment of the subject otherwise!

    3. That is a bit of a myth. First of all it was the Brits that broke the German code not the USA. The US code breakers broke the Japanese code which was also a difficult task. The Germans in WWII were good but take a look at things like their tanks. Big but would often break down. Aircraft? The FW-190 and ME-109 where okay but not really as advanced as the P-51 or P-47. German bombers were terrible. Even the Me-262 would have soon been overshadowed by the P-80 that the US was bringing into service at the end of the war.
      They where good but a lot of the myth comes from the grass is always greener.

  4. Hellschreiber (which is obviously a pun name by Herr Dr. Hell as it can mean both “Light/Bright Writer” and “Hell Writer”) is very clever, and for the 1920’s is amazing, but the problem I see with this hack is where the Hell (HA, HA!) do you get a ZX spectrum!?

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