I lived with my parents in Nigeria, in West Africa, from the early 70's until mid 80's. I'll never forget when my dad got a Telex machine for his construction company. It was like magic realising that you could key in a text message and send it anywhere in the world at the push of a few buttons! How quickly the world has changed! Thanks for the trip down memory lane!

Long ago, I used to work with an engineer named Ed. Back then, we used Bishop Graphics tape layout, so PCB design was a significant process. In order to avoid board spins, Ed would always ask for blank space on the board to include a 0.1in grid. We didn't bother to get these drilled, since if (really, when) we had to do something, we'd drill out the pads and modify the design. Once everything was stable, our PCB engineer Tim would finalize the layout and we'd call it 'done'. For more decades than I'd like to admit, we called these grids 'Ed Zones'.

I've heard those two-tones used as sound effects in in movies, radio and television to indicate “technology!” but I never knew what they were before.

My grandfather was deaf and had a Western Electric Teletype in the house up until other devices became available. I can remember it operating and the warm machine oil smell it had. I am not sure what he replaced it with. I want to say I connected to it once with my computer but that was wow long ago. In the late 2000s one of the radio stations I worked for still had a telex feed. It was a computer with a printer by then.

I am a licensed Amateur Radio Operator. I learned more about RTTY from your video than I did from 20 years as a ham! What a fascinating video! This video has inspired me to get back on the HF bands and try out some digital modes!

The rhytm of telerext machines typing is hypnotic. When I was in the Navy we used to monitor news broadcasts on HF and have teletext machines typed out breaking news.

Working for a well known British Telcommunications company back in the late 80’s I remember changing over a cable that was loaded with telex machines and we had to twist & tip solder the cable…I got so many “belts” from the wires when I stripped them I ended up wearing leather builders gloves. Much to the humour of my colleagues !! I had an old friend, William “Bill” Livens try explaining RTTY to me once my eyes glassed over but a young lad, Jamie Morgan, picked it up in 5 minutes ! Age & youth !!

My Dad had one similar at home it was thermal (UK). I used to be amazed with telex op at his office who used to be able to read the punch tape.

The wonderful thing about standards is that there are so many to choose from! When you look at the choice of audio tones, consider the following. Over the radio, the FSK will go into a sideband transmitter. Back in the day, the usual first IF on a ham rig would be 9 or 11 MHz. A 35-39 MHz LO would be out of reach for many hams, so the convention was that 160, 80 and 40 metre bands would use LSB and 20, 15 and 10 would use USB. Tuning knobs would have the scales for the higher bands printed in reverse! But more importantly, this meant that on the lower bands, the 1 bit would be the higher frequency, but on the higher bands, it would be the lower frequency. In the 1980s, most ham TNC's could decode reversed sidebands because they happened, particularly since all the new radios by then were starting something like a 45 MHz first IF with a 46-75 Mhz local oscillator. Sideband selection was done by switching the BFO frequency. And in the 21st century, RTTY, AMTOR, Hellschreiber, and a whole zoo of other digital modes are just built into the rig, implemented in software. Eric knows all this. Does it make Marc's head hurt?

WOW, what a flashback. Back around 1980 I got heavily into RTTY. Had a Model 15 Teletype that I'd stripped / Cleaned / refurbished and rewired. Looked brand new when I'd finished. Used it for many years as a printer on my Tandy TRS-80 along with a communications receiver and Oscilloscope and electronic decoder (Electronics Australia 730 kit) and tuned into news agencies all around the world. then later bought a "Tono Theta 777" decoder that did everything and connected to the computer via a serial connection and THAT did so many other things. Ahh good memories.

3:26 Nice to see I'm not the only one with a bench filled up with several projects on the go at once!

An incredible publication. Another excellent item in the historic collection. Congratulations. Thank you very much.

Another great video. Thanks Mr Pumpkinhead for the donation!

Marc: This brings back memories when I built in the late 1970s a FSK demodulator for RTTY, with my SSB Drake receiver, to drive an ex Swiss PTT teletype to receive all kind of messages. Also I had to build custom assembler code with my NatSemi SC/MP to convert from 1200 bps ASCII to 50 baudot code to drive the teleytpe. As a young eng student it was like a miracle when my PLL chip locked on to the FSK frequencies and the 'machine' started to spit out the lower case only letters... Thanks for your journey back 50 years !

I used to repair ASR-33s when in college. IIRC, the higher of the two tones is the MARK (1270/2225) and the lower is the SPACE (1070/2025). Usually, when you make a connection, your modem is expecting to see the "answer" MARK tone (2225) from the terminal answering your call. In response, your modem will send the "originate" MARK tone, (1270). These are the standard "Bell 103 modem" tones. The modem originating the call uses the lower set of frequencies and the modem answering the call uses the higher set of frequencies. An idle connection is always sending MARK. This simple FSK works at 1200 baud as well, but uses a different set of tones (Bell 202 modem). Above 1200 baud, things get much more complicated, due to the frequency limitations of the standard telephone line. Also...you can get an entire 103 modem on a chip (but it's not as much fun) Mitel MT3530BE BELL 103/V.21 Single Chip Modem, or NXP MC145443B. Trivia: Caller ID uses the Bell 202 modem tones (1200 mark/2200 space) to transmit the calling number between the first and second ring of an incoming call RTTY, as you point out, uses a different set of tones, but since it's half duplex you use the same tones for TX and RX.

Cool video with an added bonus: getting to watch Master Ken hard at work reverse engineering in the background while Eric explains the disassembled assembly code!

1070 kilohertz? Gotta be Hertz. 13:00

Takes me back to my Creed 7ERP, later relaced with a Creed 444, for RTTY. On the 7ERP you had to turn the mechanical governor adjustment screw seven and a half turns to change from 50 baud to 45.5 baud ;)

You might have enjoyed the VFCT (Variable Frequency Carrier Teletype) boxes we used back in the analog days. It allowed us to use one nominal voice channel for up to 24 TTYs.

"Always a good day when you wake up to a nice long Curious Marc video!". Correction for the start of your video 😊

Very cool Marc! I always wanted a whisper writer, and an FSK TTY modem back in the day with my dad's ham radio shack and ASR 32 and 33 TTYs.

Fascinating as always. 👍

Oh! I knew telex is what we called teletypes here, didn’t know it actually used a different code rate :) but 50Hz makes sooo much sense for the rate to use in Europe with AC power!

Love the sound of rtty. You guys rock... great video

Would love to see a demonstration of all of this on the air! And even better: the opportunity to work your station!

I don't know what is more amazing - the fact that you got the conversion working or that you actually got something figured out with Ghidra. I tried using it to reverse engineer some 8051 stuff, but the C compiler used to write the original code mixes code and data in a way that all disassemblers, including Ghidra, don't produce anything remotely usable. Had to write my own disassembler that understood some of the peculiarities of the compiler generated code...

My dad ZL2SJ built a tty modem for is vz200. It was fun showing my friends messaging like that back in the 80s

i barely understand thus channel but I can't sop watching it!

4000 character memory now finally allows long tweet support

"waiting for baudot" a new play by curious marc...

0:55 Western Onion. Are you saying you like onions fried in oil? :)

I love the massive orange light on the top. How did we ever move away from having massive lights on our electronic equipment?

Amazing work! Nothin like a Sunday Afternoon CuriousMarc episode to remind me I am beta nerd by comparison, lol. I sure hope you decide to print a final version of the modem board to make the bodge situation permanent.👌

@13:12 - "That's 10.7kHz (or thereabouts)...as his display resolution goes out to a zillion digits. I think that's pretty much bang-on in my pea brain.

I’m astonished he figured out how to do this with just two bytes: that is serious talent

I hope Eric was using at least ghidra 10.3.1 : it includes some MCS-48 bug fixes from me and others !

The Whisper Writer connected to the Noisy Writer (and of course to the Silent Writer as well)... nice! Interesting to see that audio FSK apparently was a thing with Telex in the USA. Over here, when you got a Telex connection, it would be delivered as current loop. It would be physically over a local phone line, but that would be patched through to a Telex exchange, not a phone exchange. So no modem required.

OMG that sound 27:38! Pure joy!

Simply great!

Nice build... Brings back a few memories getting going on RTTY I built the BARTG ST%V Terminal Unit, modified to run at 5V output, then wrote a Tx/Rx decoder for the CBM PET. Regarding your speed issues when the decoding did not quite work: You mentioned 45Baud and 45.5 baud a few times, and also the paperwork your showed indicated 45.5 baud. However the standard is 45.45 baud, and the difference between 45.5 and 45.45 is enough to give the effect you showed. Andy. BARTG = British Amateur Radio Teleprinter Group.

I would go mental with these high pitched tones constantly in my ears while working on them.

24:57 - And amazingly enough the covers DO fit! Much better than Dr. Frankenstein.

Fascinating.

"The XR-2211. Do you know what that is?" "The muffler bracket for a '79 Pinto?"

Some great tty action! Loved it. Make a video together with Usagi, writing at each other :)

Nice video!

Ha only you guys would do this, brilliant love it

That bodge area is very clever, if I ever design I hope I remember to do that. I'll never be a first time right kind of person 😂

I fkg love this stuff

Nice mods, I've been thinking of building my own, as I have never found anything online etc. Obviously you've had more success in the states along with your vast viewer base. My biggest holdup is a suitable keyboard, I wanted to use the old Siemens 3 row format, however this would entail custom keycaps - which is were my project is stuck.

Excellent!

That must have been like magic when it was current tech. I am just discovering rtty on hf radio with an android app. I actually think it may be useful still.

Geil!❤ btw - I learnd at Siemens in Bocholt NW/Germany 'Industrieelektroniker Gerätetechnik' - and - tada - there was the phone production for 'German Bundespost' (Telekom) later in the 90s there was founded the 'Megaset' and 'Gigaset' and there where build the Siemens cellular phones ( S4 S6 S10 and the A-Series) - today it is the 'Gigaset'-Company :-) 73 de DL1LEP

A rebadged Trendcom 200 thermal printer. Used a Trendcom 100 one with my Atari 400, driven by the joystick ports to print out program listings and their results when run.

I remember using those two XR chips in an attempt to add a cassette tape storage system to a homebrew computer in my teens. Sadly it never really worked properly -- I couldn't get it to decode at more than about 4 bytes per second. In hindsight it was probably a bad idea to build it using components scrounged out of old TV sets. :-( Later I replaced it with something much simpler that just used a single square-wave tone, generated in software, that was either on or off. The decoder consisted of a monostable. It worked great.

Dude you are hard core

Heya Marc. I see you are doing a teletype video. I have an extra 3M Whisper Writer, fully operation, from the Red Cross. It looks a bit different, has a white button instead of a red button. If ypu have use for it I'd love to donate it where it could get a loving home

That is fantastic. Digital signals from a steampunk baudot monster, translated to and from slightly less ancient teletype flavors. But could you send teletype from the moon?

The autodefrost timer on my refrigerator broke. Totally agree no one should go looking for a manual defrost refrigerator.

Reminds me of when we used to send RTTY on Commodore 64's in the '80's.

The whisper writer can also be setup to do ASCII. I worked with them back in the early 80's.

It is important to have a Juno-6 in the lab! @12:00

6:11 I have those same little powered speakers!!! Is your little blue power LED way too bright as well?

Got here after a debunking video about the lie of supposedly fastest typing person in the world. oh, this is pure gold!

Fabuloso

I'm just old enough to remember when people and companies put out telex numbers.

18:12 I laughed so hard. Just two bytes. Marc was like, "two bytes, that's what friends are for" Wisdom received: Keep friends that are close enough to you to figure out you are off by two bytes.

Is the paper still available? I think I have one of those Whisper Writers up in the attic somewhere.

The "it sounds like this" gave me a real Twin Peaks moment: I am the TELETYPE and I sound like this: bidubibidubdubidubidu

What’s up with the Juno synth in the background? I’m looking forward to hearing some Curious Kraftwerk.

Next, the smoke signal interface!

I would love to see it do Ttytdd for the deaf too. A machine that does all 3 formats. My tdd does 45.5 and50 baud. Would love to receive snd send rtty on it too.

21:25 it is frustrating how fast it can print the first part of a line (basically at scroll speed), then it has to slow down and print the rest at the baud rate.

Nice job!

If you have a shortwave radio you will often hear TTY traffic in the 14mhz ramge.

Those look like they have a similar print mechanism to the Apple Silentype I had back in the '80s.

We are calling for a collaborative video between you and @Usagi!

w00t, rtty!

14:00 The latest KZfaq app allows video zooming. Just a reminder for everyone who watches this on a tiny screen.

13:07 1070 KHz? My ears must be superhuman, super-canine, super-audio as I am sure I can hear a tone resembling C2, noticeably sharp but closer to C than C# =)

What is that loop supply you are using? Nice work!

I’d design the “prototype areas” on the board to be more like solderless breadboards, with 2 rows of connected columns 4-5 pads high, and separated by two rows, “X” pads wide; one for +Vcc, and one for ground, on 0.1” centers, of course. This way, you can transfer a small circuit directly from your real solderless breadboard over to the prototyping area pretty much verbatim. 😊 I wonder if C-3P0 has an RTTY translator built in?

Very interesting. You mentioned that the old TTY was Baudot coded. As far as i remember Baudot uses 5 bits and the newer TTYs like the asr-33 uses 8 bits. Did you have a 'convertor' or so in between or is the Whisper writer capable of talking and receiving 5 and 8 bits? BTW Do you know of the existent of converters 5/8 bits?

I just realized something. And a lot of the older sci-fi another movie is where there is some sort of computer terminal of one sort or another. It seems like a lot of times there is tones associated with texting print on the screen. I'm thinking that this is what was been going for and might be wanted this is associated with this. I'm trying my best describe this but the mind is not exactly working at the moment those brain ker-plop things! But it kind of makes sense as to do this in a movie with a computer terminal or otherwise. But then again this might have been representing some type of actual terminal. I was not around computers at the time that this type of turmoil maybe really have been used much so not sure if this is actual fact or it's just something that was done to adver Matic effect or be computer like I guess you could say input greatly appreciated Pun ntended

Dat hex edit

The Mainline ST5 will drive a 8251 USART

3:13 which one of you is gonna freestyle on that?

Hope you can create a similar mod for the Ultratec Minicom - as those are way easier to find than the 3M machines. Thank you !

It's ready to go in ssb radio. Ready to go en CB! :) I don't know if this helps in some way, but some modem chips only detects the mark tone and not the space tone. I'm thinking they use commuted filter technique to detect one but any other signal will be treated as space. If you use a SSB radio you can tune it to decode the mark tone and the other one can be dismissed. I'm thinking they use different tones based it the Rx SSB filters or local radio standard they use. I never use this, but the HAM radios have a designed input for RTTY and I'm think is for the mark signal. Keep working nice retromod..retroupgrade? :)

kool

while you're at it: replace that battery could not see if 3V or 3.6V but the latter WILL leak and corrode like crazy. 3V CR type batteries seldomly leak, but they can, just as well (and may very well be empty anyways by now)

Are there alternatives to AQV253? They seem pricey.

Interesting that the apostrophe (CURIOUSMARC'S) doesn't seem to be translated.

Think I'm first. May I have a baudot bit? 😊

That point pattern on that Western "Onion" box looks a bit... strange. Like from 80 years ago... Or Orlando.

Question for the future zombie apocalypse or whatever might collapse our communications networks. How far can this tech be used to send messages? I'm mean when the telephone networks are no longer being powered and all we have are the wires. Can we boost the signal, and how far and how easy would that be?

Should have used the 8251 USART.

THAT tone could be used to keep teenagers (and troublesome seniors) from loitering. ps What is that thing just under the Whisper Writer @ 29:33?

now, where does the 45.5 baud comes from ?? now it needs crypto capabilities (a la KW-7)

What about hellschreiber?