Teletype Model 14 Reperforator

The reperforator, the last piece of our 5-bit Baudot Teletype system, has finally been restored. Here is a little tour and demo. Explanation on how most of this works is here • Teletype Model 19 (and...
Music Credits: Swipesy Cake Walk by Scott Joplin, played by the great Scott Kirby

[@larryscott3982]

My god man! I can see the love and the reason for the love of this era of electro mechanical information technology. The BEST content on YT. Yes I binge on Curious Marc vids.

[@kbhasi]

I agree! Me too!

[@w9gb]

The 20th century started transforming mechanical to electrical, the 21st century continues this transformation.

[@AlainHubert]

Being a drummer I appreciated that the Scott Joplin (?) piano music was basically in sync with the reperf ! And being an industrial mechanic, I can also appreciate the complexity of such a beautiful machine ! And to think that there was no CAD software to design such mechanical devices back in the day. Thanks for sharing !

[@CuriousMarc]

Scott Joplin it is! Swipesy Cake Walk. Played by the inimitably cool Scott Kerby.

[@zh84]

@@CuriousMarc I also appreciated that when the video ended you let Mr Joplin come to the end of a musical phrase instead of cutting him off.

[@CuriousMarc]

@@zh84 Thanks! Glad someone noticed!

[@Colaholiker]

I wanted to make a similar comment, even though I am not an industrial mechanic, just interested in this stuff and not a drummer, but I used to play the piano until about 20 years ago. And I really loved playing Scott Joplin's music, or similar tunes from that era. Basically my favorite thing to play on the piano back then. Thanks, Marc! To be honest, I prefer videos like these over the AGC restoration. Sure enough, the technology used back then was very interesting and it is great that you guys try to make it come to life again, but on the AGC videos most things you see are guys wearing nitril gloves handling weird looking boxes with contacts between piles of wires trying to solve the puzzle. Probably a dream to participate in, but less entertaining to watch than these videos. The explanation of core memory is awesome though. So thanks for your videos, please don't see this as me complaining about them, I just wanted to mention my personal preference. And I appreciate any high quality content created for this platform! :) Now I have to get rid of my earworm of this catchy music.

[@MisterTalkingMachine]

I cannot put on words the joy those shots of the machine working along with the music brought me. Fabulous.

[@guerrerofrescotti]

Awesome! In this channel, each video is a gem. Thank you!

[@macgvrs]

That brings me back to my days as a office machine repair man. I do not miss the fun of re-soldering type faces when the solder would break and have to be re-soldered. It would sometimes take more than one try even though you were certain everything was properly aligned.

[@johnopalko5223]

There's just something about the old TeleType machines. They're wonderful to watch and listen to. The smell of the oil is nice, too.

[@TrainDriver186]

And just like that my nostrils seemed to fill with the smell of an old typewriter from 35 years ago. Not teletype admittedly, but the combination of machine oil and the inked ribbon must be about the same.

[@johnopalko5223]

@@TrainDriver186 Close. The oil has to be hot to release that unmistakable TTY aroma.

[@markhall7646]

CuriousMarc, like you I have a working model 19 now- with the "H" motor stop feature as well. I have since "inherited" 4 model 15 KSR's, two 14 TD's and one lone model 14 KTR- a typing reperforator like this one, but with its own keyboard. Thanks to your videos I have been able to restore them all, add the motor stop feature to my model 19, and all the 15 KSR's, and develop a circuit for all following your "loop boxes" design (tremendously clever!) I am in the process of locating the model 19/14 KTR/14 TD's in my radio station, the 15 KSR's in my house, shop and barn office, along with a magneto phone system! Many thanks to you and your friends for these outstanding videos- I owe you greatly!

[@CuriousMarc]

Congrats! You are on a roll! How did you get so many Baudot Teletypes? Do they grow them where you live?

[@markhall7646]

@@CuriousMarc lol it's the mountain air, the abundant rain and all the rabbit manure! It worked out about like the couple trying to get pregnant. I just quit looking and hoping and they bumrushed me!

[@bobl78]

that´s when communication technology needed regular oil and belt changes

[@andrewrobotbuilder]

"She'll do 40 characters to the gallon"

[@mattelderca]

kind of off topic, having worked on rotary dial telephone systems, there really is an inherent simplicity....and beauty in this "type" of thing.

[@andrewrixon2347]

Beautiful ! Like a work of art. Built when we were Engineers not program writers. You can see the results. There were still teletype & telex machines in operation when I first started in telecommunications 31 years ago London Heathrow Airport. It’s great to see once again. We had to be careful working on the cables as they “called” at something like 110v DC and if you were touching the wires at the time it could certainly make you jump !!

[@x0rZ15t]

What a magnificent piece of old technology. You guys are doing Gods work by restoring, preserving it and passing all the knowledge. Keep up such wonderful work!

[@ronsherr1]

I get so excited when I see that a new video has been published to the CuriousMarc channel. Thank you so much for sharing!

[@jamesseppa8135]

Such fine technology, mostly forgotten now. Thank you for keeping it alive!

[@kbhasi]

1:22 Wow, early "news wire" services were more interesting than I had initially thought. 2:00 At it again with the period era music! Great!

[@bobcharlie2337]

Wow!!! This video is a treat. Thanks

[@rejm1161]

It's the first time that I subscribe to a channel on the first video. It look like it will be very interesting. I use to work on some very old computers with punch cards. This reperf is a marvelous piece of mechanical technology. I can just imagine how the inventor was kept awake at night for just figuring out a small part of that machine.

[@rz350lc]

Congratulations on getting the final part of the puzzle together. Absolutely love the style and delivery of everthing you do for KZbin. Maybe a final technical challenge is to get hold of some old AM (Amplitude Modulation) equipment and set up an RTTY environment. Wireless teletype!

[@jlwilliams]

I just realized that in the wonderful 1973 film “The Sting,” which is set during the Great Depression, this must have been the type of machine that was used to steal the horse-racing results!

[@D3lor34n]

Love that sound

[@chap666ish]

This deserves a longer a video. A LONGER VIDEO, Y'HEAR!!!

[@SomeGuyInSandy]

Amazing!

[@bennylloyd-willner9667]

I'm so much more impressed of the old machines with the beautiful mechanics. Nowadays you just write software and let servos/motors/actuators etc do the movements with sensor feedback. It's just not the same beauty in it. Biiig thanks for another great video!

[@jgoep2310]

You seem to have selected the appropriate song that‘s exactly as fast as the Baud rate!😊👍

[@thelarch8329]

kzbin.info/www/bejne/nWOve2SfbJdlaMU

[@the_real_foamidable]

Wow, this would be a candidate for a high-speed camera and a macro lens

[@1968saigon]

I worked an operator on the 5 letter code tapes during the 1960s. At the time it was the 3rd largest major relay station as far as messages sent and received in the world . You can't imagine the noise produced by 20 or more printers, receive aisle reperfs, send aisle, high speed routing machines humming along on a 24/7 basis in prefab trailer in a relatively small area. I ran the QC on the messages as well as all the other operational aspects. The interesting part for us was when the power went down. The quite sound of no noise was very peaceful. I spent 3 year and 3 weeks in Vietnam. Thanks for sharing your knowledge so we could have a new prospective and appreciation of how it ticked. Your teaching was excellent! NNNN

[@MarcelHuguenin]

"A THING OF BEAUTY IS A JOY FOREVER!" (Dave Jones EEVBLOG)

[@ebekman]

It’s amazing era, today it’s so easy.

[@gusbert]

This would look great filmed in high speed!

[@confusedwolf7157]

Do you have a mylar tape punch / reader setup (as per the military) at the museum?

[@kevinszabo7035]

Marc, excellent video as always. WRT to the "mute" button I have a feeling that it is miswired. There isn't really a good reason for "mute" to send a break signal and cause leader to be punched. My experience with TTYs (ancient experience, 'cause I am getting toward ancient) is that the mute should have disconnect the repurf from the loop and forced loop current into the repurf (idling it). Of course, I could be wrong. On an barely related note, my favourite TTY is the ASR35 which I owned for a period of nearly 10 years (1975-1984). That was a beauty to behold as the square print block danced across the page. Unfortunately adult endeavours and changing priorities required a liberation of the space it consumed :-)

[@CuriousMarc]

That got me thinking for a second too. It’s not a line break. It simply shorts the output to the reperf. So it does not interrupt the loop and avoids making the rest of the devices in the loop chatter. Simple and efficient. Shown as such on the schematics too, so we’re pretty sure it’s correct.

[@kevinszabo7035]

@@CuriousMarc thanks for the additional explanation. Seems a peculiar mode of operation but there must of been a good reason back in the day. BTW, when I said "Break" I meant that the repurf was seeing a Break signal (zero current) since with its input shorted there was no current through its solenoid. I understand the loop is contiguous and the rest of the system has is seeing MARK because the 60mA is flowing. Since the repurf has been partitioned out of it it has no current and thus sees continuous SPACE (Break). Wow, it's been so long. I hope I haven't got my nomenclature backwards. Thanks again for the trip through memory lane

[@DanBowkley]

If ever there was a perfect place to insert some gratuitous high speed video, this is it...

[@DandyDon1]

I'm curious how similar the Western Union paper strip printer was to the reperferator mechanism.

[@staceybabepeterstaceyenter1269]

Coolest

[@edgeeffect]

That's right.... when the AGC gets too frustrating, go back to the Telytype for a while. ;)

[@carlclaunch793]

Life presents us with thousands of interesting projects and only a single timeline to accomplish them all. During any time someone is waiting on one project, you can hop over and play with another. Works like that for me, anyhow.

[@compu85]

Does the reader have to be set up specially for the chadless tape? I presume optical readers wound’t work with this... by the 70s were there many “new” tape readers that were mechanical?

[@carlclaunch793]

The regular readers, which had spring loaded pins that would push up through holes, also push the chad flap up and read accurately.

[@MarionMakarewicz]

My new Electronica Metal band name is Chadless Punch

[@gcewing]

So, hanging chads are actually a feature of this machine!

[@jacoforall]

The exact position where it punches can't be the same position where it prints, right? So it punches where the previous character is printed on the tape?

[@CuriousMarc]

And you are absolutely right! It’s 6 characters off.

[@miriamn9657]

So the Model 19 cannot punch incoming transmissions? Why? Magnet and keyboard drive the same bars which in turn control the punch, so that shouldn't matter. I'm just wondering, as german machines had that feature and it was used extensively. Reperforators were almost unkown here, the only big user I know of was the dpa. All others preferred having the message printed by default and kicked the punch in when it was needed.

[@matthewkriebel7342]

Is the typeface upside-down (and backwards?) on that?

[@CuriousMarc]

Sure is!

[@525Lines]

5:54 New Dymo tape. Gotta be a real vet to remember that stuff. Now, to find a new ink ribbon ...

[@CuriousMarc]

Actually, the ink ribbons are available off the shelf at Staples. They have not changed the design is 94 years!

[@phonotical]

How quickly would those things chew through a ribbon?

[@CuriousMarc]

Ribbon goes by pretty fast, but it reverses automatically at either end, leaving time for the ink to redistribute evenly. So it actually lasts for a while.

[@yoerim360]

what do you use to power the teletype when not on the desk power source? like when you where restoring it , you used something in blue boxes

[@CuriousMarc]

The supply shown in the videos is a HP 6645A that can do up to 120V DC. The blue boxes are for the current control resistor and loop jacks (explained in this episode kzbin.info/www/bejne/rnW9nKR_fryinM0). Eventually I bought a cheaper asian Tekpower TP12001X 120V power supply dedicated to this setup. A bit annoying to setup the current limit the first time, but otherwise works great. Got it from Walmart online: www.walmart.com/ip/TekPower-TP12001X-120V-DC-Variable-Switching-Power-Supply-Output-0-120V-1A-Digital-Display-With-Back-Light/144911196

[@yoerim360]

@@CuriousMarc seems the link is gone?

[@dumky]

I noticed 5 semi-circular parts on the top of the machine, which seem to be shifted by 5 arms going down the right side. Do you know what they do?

[@dumky]

Found your explanation (around 8m00s) in an earlier video. Awesome! kzbin.info/www/bejne/q5iYnYh_Ys2madU

[@carlclaunch793]

The semi-circular parts have slots milled in them. They are shifted to one side or the other based on the condition (mark or space) of the incoming bits. When all five bits have arrived and the semi-circular parts are in their final configuration, the mechanism releases all the type lever assemblies. Only one will have slots lined up in all the semi-circular parts, thus only that one falls forward a bit into the slots. This is a selector. It has selected one of the type bars, the one that is associated with the particular pattern of incoming bits. The type lever that has moved forward is contacted by the moving mechanism, causing the type bar itself to fling forward and strike the ribbon, tape and platen. The arms going down the right side carry those same positions, the captured character code, down to the punch unit.

[@CuriousMarc]

How it works is also explained in this video here: kzbin.info/www/bejne/oKnOqpqNfpKKnNU

[@ppokorny99]

Watching it print letters and numbers it hits me that a similar or same mechanism must have been used for stock ticker printers. Even today when you see scrolling stock quote ticker tapes the letters are on the top and the numbers on the bottom of the tape Also, I wonder if you were aware how these same tty with baudot code were used by the deaf community to communicate over the telephone.

[@pauldzim]

Don't understand how the T/D can read holes with the chad still attached? Did you see any errors when reading the tape?

[@gcewing]

Probably the holes are read by pins that push the chads aside.

[@CuriousMarc]

@Greg Ewin: Bingo!

[@willemkossen]

Everytime i see machines like that i kinda want one. I’ld never use it, i dont have space for it, i couldnt fix or operate it, but still, i want a teletype....

[@Veso266]

where do you buy this (pink) paper, is this old stock or you are producing it

[@CuriousMarc]

Old stock, from the one and only Mr. RTTY: kzbin.info/www/bejne/Y32naWpoerx-l6c

[@ingusmant]

Maybe a dumb question but why didn't they make a tape variant that was wider so you could print the code in an unpunched area?

[@CuriousMarc]

Because you want the resulting punched tape to be inserted in a regular T/D for transmission. That constrains you to a standard tape width. The chadless tape is quite a clever workaround!

[@TheRealColBosch]

It's down to simple bureaucratic inertia. Businesses and governments had already standardized on a tape width. They'd rather put up with a little inconvenience than replace all of their machines. I don't know if there were millions of teletypewriters, but I wouldn't be too surprised if there were. That's a lot of throwing out perfectly good equipment just to get a relatively tiny improvement.

[@vlycop7404]

This lake all the good part, where are the 10H of try and learn ? the debugging ? Great video non the less, but my nerdy side stay hungry for more :p

[@CuriousMarc]

I know. We did most of it off camera so we could finish it up quickly - that project got terribly late.

[@typograf62]

Punch and forward

[@kevinreardon2558]

This is great, thank you. Now, how about White Out? Did that work with this? What about backspace?

[@CuriousMarc]

Actually on the Model 19 perforator, there is a backspace key that enables you to correct tape errors. The way it works is explained in the Model 19 demo video.

[@aidenstech1285]

5:20 Is that an Australian plug?

[@gorillaau]

Yes, it is. Though we are not the only country to use that slanted pin styled plug.

[@TheRealColBosch]

Was there ever a device that could be attached after the T/D unit to "erase" the tape by automatically punching five holes in every character, making the tape impossible to read afterwards, or perhaps a shredding unit? I'm sure that operators would burn used tapes regularly in sensitive situations, but it would be another tool for security. Because if not, all we'd need is a time machine, and we could be rolling in it. ...or has the 21st Century just made me intensely paranoid?

[@cpufreak101]

I mean, being paper I can imagine just burning it would suffice

[@carlclaunch793]

There is a character that punches all five holes - it is the equivalent of 'white out' to correct a mistyped character by causing the reader to skip over it. You would back up, type that character to punch all holes, then type the corrected character. For security purposes, it wouldn't be sufficient. Tiny alignment differences between the original holes and the new five punches likely would leave remnants you could observe somewhere around the rim of the hole to detect where a hole had been previously punched. I bet you could recreate a substantial portion of the text this way given enough time to study the tape. Burning it seems to be better, but then the ashes have to be stirred or pulverized to be sure that blackened shreds don't give away parts of the message

[@davidmcgill1000]

@@carlclaunch793 So a machine that cuts the ribbon in half and splices it back together in correct places, then sets fire to the removed portion.

[@TheRealColBosch]

@@carlclaunch793 One of the things I most like about this channel is that so many of the folks in Marc's videos are willing to respond to comments here. Sometimes I learn as much from the comments as I do from the videos themselves, and that's not a thing I ever thought I'd write on KZbin.

[@Eo_Tunun]

These things kind of make me think of the Antikytera mechanism all the time. The complexity, the precision of make… The ancient Greeks basically had what it takes to make teletypes. They didn't. *Not so clever after all, eh?* ^^)

[@AA-iq6ev]

"Just send a message"

[@thcoura]

The bill of materials to put this device together might be over 200