Almost-Modern TeleType Is Silent

If you’ve ever used a real TeleType machine or seen a movie with a newsroom, you know that one TeleType makes a lot of noise and several make even more.[CuriousMarc] acquired the silent replacement, a real wonder of its day, the TI Silent 703. The $2,600 machine was portable if you think hauling a 25-pound suitcase around is portable. In 1971, it was definitely a step up.

The machine used a thermal printer, could have a built-in acoustic coupler for talking over the phone. You could also get a dual tape drive that acted like a mostly silent paper tape reader and punch.

Of course, thermal printers require thermal paper, which has its own issues. [Marc] doesn’t just turn the machine on, but connects it through an RS232 analyzer and scope to get it working as a real I/O device. He also tears into it, something you probably couldn’t do back in the day since you probably leased them rather than pay the total price which is almost $18,000 today.

There was surprisingly little inside and, of course, compared to a real TeleType, very few mechanical parts.  If you remove the printer and power supply, there’s a simple CPU board and a modem board, none of which look terribly sophisticated. The highlight, though, is watching it trade traffic with an ASR33.

If you really want to get into TeleTypes, you can use one as a Linux console if you have a Baudot to ASCII decoder ring. Or use one to send text messages.

25 thoughts on “Almost-Modern TeleType Is Silent

  1. “If you really want to get into TeleTypes, you can use one as a Linux console if you have a Baudot to ASCII decoder ring.”

    ASCII TeleTypes we’re very, very common in the timesharing world, and found a new home in the burgeoning personal computer world.

    1. People used Baudot machines for radioteletype, and the system to help the deaf communicate over the phone.

      So at the point of the Altair, they were the machines most likely to be in hobbyist hands.

      So yes, they saw some computer useage. But you needed a conversion, and had to deal with missing characters. Only viable if you had a machine.

      You could buy an ASCII tty from MITS if I recall. And right about that point they were starting to appear as surplus. Since ASCII wasn’t yet allowed on the ham bands, they were only useful for computers.

      Anything coming in, TTYs, glass terminals, printers woukd have been ASCII. The Silentypes were ASCII too.

      SWTP had a forty column printer, just the mechanism. That and an ASCII keyboard would you an almost modern TTY

      1. I heard of those but never actually saw one. I’ve torn apart the 28s many times. Only been inside a 33 a few times. I loved the key rollover mechanism on the 28…. who thinks of that stuff?

  2. I had my first ever computer programming class on Silent 700 terminals at Marquette University around 1973 or 74. IRIC they were connected to a PDP-11 and we programmed in Fortran 4. They were very fast and quiet compared to other printing terminals of the day, and there were no punch cards or paper tape.

  3. In the mid 80s, I did some contract work for a guy whose customers were the “big 3” car companies who were trying to “upgrade” their equipment. One job was update for some Ford assembly plants. Every night, HQ (Detroit) sent work orders for daily builds to an IBM “something” at each factory, and that IBM machine would then broadcast cryptic jobs sent to each work station’s ASR33 printer via an factory-wide current loop (not sure what current was used) “network”. Originally, each station would tear of a vehicle “build” for their station from the ASR33 and then had to decipher what parts to get for their work (e.g. red bucket seats). The first phase of the upgrade was to convert those ASR33 stations into 25″ color CRTs that used CGA cards to pick out what that station’s codes were, convert that to something more readable and display those specific work info for that station as 3 sets of two lines of BIG letters of different color. Part of that was to synchronize the vehicle number to each station (part of each build order), which used to be done manually and was error prone (i.e. might result in green bucket seats in a red car). It system also had to hand rework and reordering of vehicles that were temporarily pulled off the line and then reinserted later (messy stuff).

    One of the last upgrades was to intercept a specific ASCII string, convert it into Baudot, and then send it to a VIN plate punch machine (that obviously only knew Baudot) twice, since it had to punch two sets of plates (one on the dash and the other for the engine block).

    I did all this work off-site and it worked the first time it was tested. I never had a Baudot anything to test it on. Simpler time, huh? My employer got several “awards” from the auto makers, especially Ford, who claimed that it improved their daily production by 20% or more, especially for the resequenced/reworked cars.

  4. To say that the Teletype was noisy, is an understatement. In 1976 I resqued a broken one from a dumpster and repaired it.
    In a noisy mainframe room it was loud but tolerable, in my study though, it sounded as if there was war going on. In the end, I had to get rid of it, because it would put my wife in a rage!

    1. I love the rhythm of the Teletype. I used to have one in my dorm room. I pity the person in the room below. My wife understands, but I think she appreciates my Laserjet 5 a lot more than the old TTY :-)

  5. I remember reading about how there are chemicals in thermal paper that can absorb through your skin. I think it was something that in the body mimics estrogen, maybe BPA, I don’t know. They also said that hand sanitizer actually makes one’s skin more permeable to the stuff.

    Well, if getting a receipt from the grocery store can affect ones health then I wonder what using one of these teletypes day after day did.

    1. I also had an old flexowriter and yes they were even heavier than the old 28s and certainly heavier than a mostly plastic machine like the 33. I don’t know if it was just mine or not but it had a very distinct smell to it as well which I assume was the lubricant or maybe pent up tobacco smoke from the last owner lol.

      1. That smell should remind you of your age, or should I say heritage?

        My great grandfather’s pendulum clock came with a small bottle that he referred to as “organ oil”. This oil has a distinctive – but not unpleasant odor – that I have learned to associate with very old, precision machinery. I suspect that this is what you smelled.

        This oil was harvested from sperm whales, and before the Endangered Species Act., it was widely used for many types of light machinery. Today, because of the law, it has been replaced with synthetic oils.

  6. I used to work on KSR-35 teletypes for the Navy 10 yrs ago. Fun stuff, setting 100 little levers and pivot points. Lubing the chassis up. Adjusting everydamnthing. I also made an adapter to hook the teletypes up to a serial port to test them with a pc instead of the OJ172. Worked well enough most of the time. On worn out units the timing was a bit fast.

    1. I had a KSR35 surplus from the phone company which I used for I/O for the single board computer I built in 1979. It was a tank! Our basement flooded twice and although it got soaked, after it dried up it ran fine!

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