Teletype Basic Ro Repair Manual Teletype
Kanisha Dezarn
threads with questions on how to do something with teletype. some of these threads are pretty old, so things that were considered impossible might be entirely possible now. if you have a question and none of these threads answer it, post it here: Teletype workflow, basics, and questions
for additional control, you can use 16n faderbank or other i2c enabled controllers (via i2c) or grid and MIDI controllers (via the USB port). for the latter, make sure your case provides sufficient power! also, if you have an older revision of teletype (green PCB), you might need to power USB devices externally - see below.
teletype can also talk to many i2c enabled modules - telexo, just friends, er-301, disting ex and many more. see the relevant section below. use this thread for any questions on how to connect i2c devices:
nothing reveals teletype potential like i2c. it was added first to control the monome trilogy modules, but since then grew into a sprawling ecosystem - i2c enabled controllers, additional inputs and outputs, sound processors and generators, all controlled directly from teletype without patch cables.
While the manufacturer called the Model 33 teleprinter with a tape punch and tape reader a "Model 33 ASR", many computer users used the shorter term "ASR-33". The earliest known source for this equipment naming discrepancy comes from Digital Equipment Corporation (DEC) documentation,[6] where the September 1963 PDP-4 brochure calls the Teletype Model 28 KSR a "KSR-28" in the paragraph titled "Printer-Keyboard and Control Type 65". This naming convention was extended from the Teletype Model 28 to other Teletype equipment in later DEC documentation, consistent with DEC's practice of designating equipment using letters followed by numerals. For example, the DEC PDP-15 price list from April 1970 lists a number of Teletype Corporation teletypewriters using this alternative naming convention.[7] This practice was widely adopted as other computer manufacturers published their documentation. For example, Micro Instrumentation and Telemetry Systems marketed the Teletype Model 33 ASR as "Teletype ASR-33".
"Dumb terminals", such as the low-cost ADM-3A (1976) began to undercut the market for Teletype terminals. Such basic video terminals, which could only sequentially display lines of text and scroll them, were often called glass teletypes ("glass TTYs") analogous to the Teletype printers. More-advanced video terminals, such as the Digital Equipment Corporation VT100 (1978), could communicate much faster than electromechanical printers, and could support use of a full-screen text editor program without generating large amounts of paper printouts. Teletype machines were gradually replaced in new installations by much faster dot-matrix printers and video terminals in the middle-to-late 1970s.
Grid integration allows you to use grid to visualize, control and execute teletype scripts. You can create your own UIs using grid ops, or control Teletype directly with the Grid Control mode. Built in Grid Visualizer allows designing and using grid scenes without a grid. For more information and examples of grid scenes please see the Grid Studies.
An internal metronome executes the M script at a specified rate (in ms). By default the metronome is enabled (M.ACT 1) and set to 1000ms (M 1000). The metro can be set as fast as 25ms (M 25). An additional M! op allows for setting the metronome to experimental rates as high as 2ms (M! 2). WARNING: when using a large number of i2c commands in the M script at metro speeds beyond the 25ms teletype stability issues can occur.
Grid operators allow creating scenes that can interact with grid connected to teletype (important: if your Teletype has a green PCB, grid must be powered externally, do not connect it directly to teletype! See the power section of our grid docs for external powering suggestions. Black PCB units are the only version capable of providing power to grid.). You can light up individual LEDs, draw shapes and create controls (such as buttons and faders) that can be used to trigger and control scripts. You can take advantage of grid operators even without an actual grid by using the built in Grid Visualizer.
Generic I2C ops allow querying and sending commands to any I2C enabled devices connected to teletype. Before you can send or query you need to set the I2C address of the device using II.A (you might want to place that in your INIT script so that the address is set when you load a scene).
You can send up to 3 additional parameters, which can be either byte values or full range teletype values (for something like velocity), which will get sent as 2 bytes (MSB followed by LSB). All parameters must be of the same type - if you need to send both byte and word values, use the bitshift ops to combine/split bytes.
I picked up an old army an/ugc-74A(V)3 teletype in really good condition but no power. I'm looking for some troubleshooting info for it. I found the pinout for the PS TP1-TP16 but any insider knowledge of any other test points to check (hopefully with a circuit diagram and/or schematic to match) that might help me narrow it down would be appreciated.
A Teletypewriter (TTY) Installer is a professional who installs and repairs telegraphic transmitting and receiving equipment. A teletypewriter is known as an electromechanical typewriter meant for point-to-point communication. According to the U.S. Bureau of Labor and Statistics (BLS), a Teletypewriter Installer falls into the category of telecommunication equipment installer (telex).
A teletypewriter is also known as a teletype machine, teleprinter, or just a teletype. The installer adjusts the features, link the proper interface, and fix minor troubles. They will occasionally inspect, lubricate, and clean the terminal during a service interval for better functionality. Some companies have replaced the teleprinter with electronic computer terminals.
To become a teletypewriter, the professionals need to have essential skills which will help boost their career. They should have an understanding of transmission, switching, broadcasting, control, and procedure of telecom systems.
The second most complicated unit in the Model 28 KSR is the keyboard. It contains the keyboard itself and the signal generator (which turns keypresses into serial Baudot signals), as well as providing a mount for the motor unit and terminal unit. On some teletypes it additionally includes an automatic answer-back mechanism capable of spooling out 20 Baudot characters.
The bad news is that the lead-in wires on the motor are tied (and possibly epoxied) into the windings. However, once they enter the motor case, they are rather firmly bound in place with lacing and cannot move much, so the insulation past the grommet at the case was in pretty good shape. I was able to carefully cut and strip the lead-in wires near the motor case, solder on a short length of line cord (cut out of an IEC power cable), and wire it to the appropriate terminals on the motor unit chassis. There are three wires leading into the motor, two for the primary winding and one for the outboard end of the starter winding, so a three-wire line cord does the job neatly. I do not know how long the line cord will survive in that environment (I suspect the original wires failed due to the large quantities of oil in the motor unit and the teletype cabinet in general), but so far it is at least not leaking to the chassis!
In the Teletype Corporation manuals being used as the source material some variants of a Model 33 teletype could easily be used without the metal stand. Catch is the Teletype model 33 ASR is the exception due to the papertape punch. I certainly can't say that it was impossible to use on a desk because if you throw enough money at a purely mechanical problem like this they can usually be solved.
In 1869, the stock ticker was invented. It was an electro-mechanicalmachine consisting of a typewriter, a long pair of wires and a ticker tapeprinter, and its purpose was to distribute stock prices over long distances inrealtime. This concept gradually evolved into the faster, ASCII-basedteletype. Teletypes were once connected across the world in a largenetwork, called Telex, which was used for transferring commercialtelegrams, but the teletypes weren't connected to any computers yet.
There was a plethora of teletype models around, all slightly different, sosome kind of software compatibility layer was called for. In the UNIX world,the approach was to let the operating system kernel handle all the low-leveldetails, such as word length, baud rate, flow control, parity, control codesfor rudimentary line editing and so on. Fancy cursor movements, colour outputand other advanced features made possible in the late 1970s by solid statevideo terminals such as the VT-100, were left to the applications.
A user types at a terminal (a physical teletype). This terminal is connectedthrough a pair of wires to a UART (Universal Asynchronous Receiver andTransmitter) on the computer. The operating system contains a UART driver whichmanages the physical transmission of bytes, including parity checks and flowcontrol. In a naïve system, the UART driver would then deliver the incomingbytes directly to some application process. But such an approach would lack thefollowing essential features:
Next on the list is restoring the very same Ascii encoded KSR-33 which I owned and used as a computer printer in the 80's. Being a KSR unit, it doesn't have the paper punch or reader. While I had completely forgotten what I had done with it, an old friend called me when he heard I was looking for one, and reminded me that I had loaned him the machine in the mid-80's after I had gotten a Star-Micronics dot-matrix printer to use with my C-64 computer. This was originally an Island Tel machine, one of several given to local Hams in 1985 - I was one of the fortunate ones to get one at the time. My friend had used it for a couple of years, then it was consigned to his barn, and it spent the next 20 some years there. This is bad news for teletypes, and it suffered the usual barn damage, not only limited to becoming a home to PEI's red squirrels (the size of chipmunks), but also rust damage to many parts, and some heavy item through the years had fallen on its top, breaking the top cover and the platen, and the platen knob at the left hand side and bent the paper guides badly. These machines survive storage best when heated, dry, and kept free from critters! Despite this, I am very happy to have it back and to have the chance to refurbish it to its former glory. I am trying to restore it. I have it mostly operating now - fortunately much of the rusting was superficial, but some serious. However, if I find too much needs replacing, there is an ASR-33 coming in July thanks to a lady in the U.S. It appears to be in very good shape, and had been in good, heated storage. This KSR-33 will end up serving as a source of parts for the better ASR-33. The major difference between a KSR-33 and an ASR-33, is that the ASR version has a tape punch and tape reader on the left hand side of the machine, making it much more suitable for the display and demonstrations, whereas the KSR version does not. Meanwhile, working on this machine will teach me a lot about their operation and servicing. Thankfully, I have a full set of service manuals for both machines on CD Rom. Normally, it wouldn't be worth putting all this time, effort and expense into a KSR-33, but this was my machine originally, and to me, it is worth it, if only for sentimental reasons, to get it running again. Many would consider it a lost cause! KSR-33 before with only some cleaning - much work done since then. Platen broken on left
side, and the left hand protusion which the knob slips on is broken off. Seems I have been cleaning this machine for a week. During cleaning, various seed husks were found inside the machine - even a small spruce cone was found under the keyboard where someone had stored it in case of a rainy day, and despite all the husks I have already removed in the last week, these have continued to be a problem. I finally decided to soak the base of the printer in Varsol April 27th, 2010, of course first removing the motor, starter and capacitor. You should have seen all the husks flooding out of inaccessable areas when I poured the Varsol into the Rubbermade tote I used to contain it! Aside from the husks, it will also remove old dried up grease, oil, and 20 years of dirt from it's storage. Tomorrow, I will use the parts brush on it, and then blow anything I missed out with a compressor. Once this is done, it will have to be re-lubricated again. Front - After soaking - still wet. Motor end (back) after soaking - still wet. One of the major problems I am having with this machine are springs weakened by rust breaking near their ends. I am replacing these one by one as they break, and am trying to locate replacements for most of the small springs in the unit. They are the ones most effected by the rust. The gummy print hammer bumper has been replaced by a 7/16" clear plastic tubing, the preferred replacement as even NOS hammers have gone gummy with age. After the old bumper is removed, a half inch section of this tubing is slipped over the hammer from the top to the "T" portion to replace it. It is a nice, tight fit, and easy to replace. This has been found to be an adequate replacement by others. If this isn't done, it will beat up the print head in short order. When done, it will have had extensive cleaning, lubrication, and adjustment. I have been able to find a source for a new cover, new platen, new knob and a replacement print carriage shaft. These been received and installed in its heavily damaged upper printer section. I am hoping it will soon work great again, as it did when loaned to my friend. I will eventually post an after shot when done. It should look significantly better than it does in the first shot above. April 30, 2010 - The printer was re-mounted after cleaning, and the platen replaced. The machine sure is a lot cleaner. I am having problems with the carriage return and paper feed but all else seems to be working. Of course, I won't be able to tell for certain until the CR and line feed is working. Work is continuing on the project! Overall view before major cleaning, Paper guide flipped up to show
platen break and missing end the manual feed knob fits on. Machine cleaned and new platen installed - looking better!
Saturday, May 1st, 2010 - I didn't get too much done on the machine due to other comittments - but did get a lot of much needed clean-up done in the teletype display area. The solvent was poured from the Rubbermaid tub in which the machine was soaked, back into the jugs it came in, tools put away, and a general consolidation of the mess. A small cabinet found in a yard sale this morning was placed in the display area and loaded with teletype supplies. Then the afternoon was spent helping some people pick up my spare phone booth to clear up some valuable space in my barn. I guess one could call it a day of consolidation. The top cover and new platen cover has been placed on the machine temporarily until I work on it again to keep the dust out.