3 ms·

Reminds me of the 90s when people had beepers, and everyone would send each other long strings of numbers that they knew how to translate into sentences. Beeper

Reminds me of the 90s when people had beepers, and everyone would send each other long strings of numbers that they knew how to translate into sentences. Beepers were in a way, the original texting device.

genewitch 5y ago
I understand your point, here - so don't take offense, please. The Hellschreiber was invented in the 1920s, and the "protocol" is still in use today. CW transmission of symbols (Morse code, for instance) began around 1913, this is after, of course, spark gap transmitters (such as those used on the Titanic) and telegraph. I personally cannot understand or use CW/Morse, but i have radios and software that do it for me. There are extremely tiny, battery powered CW radios, usually costing $50-$300. If one can use CW and understand it, that's wireless, telephoneless communication. Hellschreiber, though, requires a display (or clever OCR, due to the way it is transmitted over 3 identical horizontal lines), but a chiclet style keyboard could be used. Unfortunately i don't know of any consumer-y way to do any of this. APRS(c. 1984) 100% could do tiny, text-only messaging, and in fact does already, but requires licensing. I can send a text message to anyone at an internet connected device with a screen, or anyone, anywhere with a radio that supports it. X.25(1976) also exists, as does PACTOR(1991), both of which in theory don't need much more than a display and a way to input characters. Back to my point, though, telegraphs have existed since before 1792, and the idea was to be able to see semaphore further away. Electrical telegraphy(1809) was first 35 wires in 35 tubes of acid and the operator had to watch for bubbles in each tube. But about 110 years after that, teletype became more prevalent, and there we have Hellschreiber.
- gkbrk 5y ago
  Always nice to see people mention radio stuff on HN. Just a quick remark, I believe Hellschreiber is transmitted as a single line, just displayed as multiple in order to get around the skew caused by timing differences.
  - genewitch 5y ago
    You're correct, although it's not technically "a line" it's a column of "on" or "off" - the receiver is, per the protocol, supposed to output at least one copy of each character. The wiki mentions that having three possible rows allows for deviations in timing, however, three rows also allows for deviation of frequency. Today's radios, combined with FLOSS (or at least 'source available') software can get timing synchronized within 20ms, including the delay in actually getting the RF out of the 'antenna' - pci latency, soundcard buffer latency, radio soundcard latency (if you're using a radio that connects via USB, see ic-7100 for example). When I use WSJT-X, which is "weak signal" software, i routinely notice less than 1s timing deviation median. WSJT-X relies on the system clock that the software uses to be accurate, as transmissions start at published times - like exactly on the minute boundary, :00. all reception reports include the time delta. As another data point, slow hell mode uses 30hz of bandwidth, and i have used kiwisdr websites to 'hear myself' nearly everywhere in the world using slow hell mode. No one else is using this mode, so i generally have to use kiwisdr to test different modes, antennas, and radios. Another open source project, iirc.
- aceazzameen 5y ago
  Great details and history here. Thanks.

genewitch 5y ago

I understand your point, here - so don't take offense, please. The Hellschreiber was invented in the 1920s, and the "protocol" is still in use today. CW transmission of symbols (Morse code, for instance) began around 1913, this is after, of course, spark gap transmitters (such as those used on the Titanic) and telegraph. I personally cannot understand or use CW/Morse, but i have radios and software that do it for me. There are extremely tiny, battery powered CW radios, usually costing $50-$300. If one can use CW and understand it, that's wireless, telephoneless communication. Hellschreiber, though, requires a display (or clever OCR, due to the way it is transmitted over 3 identical horizontal lines), but a chiclet style keyboard could be used. Unfortunately i don't know of any consumer-y way to do any of this. APRS(c. 1984) 100% could do tiny, text-only messaging, and in fact does already, but requires licensing. I can send a text message to anyone at an internet connected device with a screen, or anyone, anywhere with a radio that supports it. X.25(1976) also exists, as does PACTOR(1991), both of which in theory don't need much more than a display and a way to input characters. Back to my point, though, telegraphs have existed since before 1792, and the idea was to be able to see semaphore further away. Electrical telegraphy(1809) was first 35 wires in 35 tubes of acid and the operator had to watch for bubbles in each tube. But about 110 years after that, teletype became more prevalent, and there we have Hellschreiber.

gkbrk 5y ago
Always nice to see people mention radio stuff on HN. Just a quick remark, I believe Hellschreiber is transmitted as a single line, just displayed as multiple in order to get around the skew caused by timing differences.
- genewitch 5y ago
  You're correct, although it's not technically "a line" it's a column of "on" or "off" - the receiver is, per the protocol, supposed to output at least one copy of each character. The wiki mentions that having three possible rows allows for deviations in timing, however, three rows also allows for deviation of frequency. Today's radios, combined with FLOSS (or at least 'source available') software can get timing synchronized within 20ms, including the delay in actually getting the RF out of the 'antenna' - pci latency, soundcard buffer latency, radio soundcard latency (if you're using a radio that connects via USB, see ic-7100 for example). When I use WSJT-X, which is "weak signal" software, i routinely notice less than 1s timing deviation median. WSJT-X relies on the system clock that the software uses to be accurate, as transmissions start at published times - like exactly on the minute boundary, :00. all reception reports include the time delta. As another data point, slow hell mode uses 30hz of bandwidth, and i have used kiwisdr websites to 'hear myself' nearly everywhere in the world using slow hell mode. No one else is using this mode, so i generally have to use kiwisdr to test different modes, antennas, and radios. Another open source project, iirc.
aceazzameen 5y ago
Great details and history here. Thanks.