teletype

27 Articles

A Lorenz Teletype Shows Us Its Secrets

October 7, 2025 by 23 Comments

When we use the command line on Linux, we often refer to it as a terminal. It’s a word with a past invoking images of serial terminals, rows of green-screened machines hooked up to a central computer somewhere. Those in turn were electronic versions of mechanical teletypes, and it’s one of these machines we’re bringing you today. [DipDoT] has a Lorenz teletype from the 1950s, and he’s taking us through servicing and cleaning it, eventually showing us its inner workings.

The machine in question had been in storage for many years, but remained in good condition. To be this long out of use though meant it needed a thorough clean, so he sets about oiling the many hundreds of maintenance points listed in a Lorenz manual. It’s a pleasant surprise for us to see keyboard and printer unit come away from the chassis for servicing so easily, and by stepping it through its operation step by step we can see how it works in detail. It even incorporates an identifier key — think of it as a mechanical ROM that stores a sequence of letters — which leads him to believe it may have come from a New York news office. The video is below the break, and makes for an interesting watch.

He’s going to use it with a relay computer, but if you don’t have one of those there are more modern ways to do it.

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Retrotechtacular: The Noisy Home Computer From 1967

September 8, 2025 by 22 Comments

[Rex Malik] didn’t need an alarm clock. That’s because he had one of two “home computer terminals” next to his bed and, as you can see in the video below, it made quite a racket. The terminal looks like an ASR33 with some modifications. In 1967, it was quite a novelty and, of course, it didn’t have any real processing power. It connected to an “invisible brain” ten miles away.

What do you do with a computer in 1967? Well, it looks like you could trade stocks. It also apparently managed his shopping list and calendar. His young son also learned some letters and numbers. We’d love to hear from the young [Mr. Malik] today to find out what kind of computer he’s using now.

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You Know This Font, But You Don’t Really Know It

February 15, 2025 by 20 Comments

Typography enthusiasts reach a point at which they can recognise a font after seeing only a few letters in the wild, and usually identify its close family if not the font itself. It’s unusual then for a font to leave them completely stumped, but that’s where [Marcin Wichary] found himself. He noticed a font which many of you will also have seen, on typewriter and older terminal keys. It has a few unusual features that run contrary to normal font design such as slightly odd-shaped letters and a constant width line, and once he started looking, it appeared everywhere. Finding its origin led back well over a century, and led him to places as diverse as New York street furniture and NASA elevators.

The font in question is called Gorton, and it came from the Gorton Machine Co, a Wisconsin manufacturer. It’s a font designed for a mechanical router, which is why it appears on so much custom signage and utilitarian components such as keyboard keys. Surprisingly its history leads back into the 19th century, predating many of the much more well-know sans serif fonts. So keep an eye out for it on your retro tech, and you’ll find that you’ve seen a lot more of it than you ever knew. If you are a fellow font-head, you might also know the Hershey Font, and we just ran a piece on the magnetic check fonts last week.

Thanks [Martina] for the tip!

A Teletype By Any Other Name: The Early E-mail And Wordprocessor

November 13, 2024 by 40 Comments

Some brand names become the de facto name for the generic product. Xerox, for example. Or Velcro. Teletype was a trademark, but it has come to mean just about any teleprinter communicating with another teleprinter or a computer. The actual trademark belonged to The Teletype Corporation, part of Western Electric, which was, of course, part of AT&T. But there were many other companies that made teleprinters, some of which were very influential.

The teleprinter predates the computer by quite a bit. The original impetus for their development was to reduce the need for skilled telegraph operators. In addition, they found use as crude wordprocessors, although that term wouldn’t be used for quite some time.

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Check Out This PDP-11 Running Unix With A Teletype Terminal

January 16, 2024 by 19 Comments

If you’ve spent a few years around Hackaday, you’ve probably seen or heard of the DEC PDP-11 before. It was one of the great machines of the minicomputer era, back when machines like the Apple ][ and the Commodore 64 weren’t even a gleam in their creator’s eyes. You’ve also probably heard of Unix, given that so many of us use Linux on the regular. Well, now you can see them both in action, as [HappyComputerGuy] fires up real Unix on a real PDP-11/73… with a real Teletype Model 33 to boot!

It’s a fascinating dive into the tech of yesteryear, with a rich dose of history to boot. It’s mindboggling to think that video terminals were once prohibitively expensive and that teletype printers were the norm for interacting with computers. The idea of interacting with a live machine via a printed page is alien, but it’s how things were done! We’re also treated to a lesson on how to boot the PDP-11 with 2.11BSD which is a hilariously manual process. It also takes a very long time. [HappyComputerGuy] then shows off the Teletype Model 33 rocking the banner command to great effect.

It’s awesome to see this hardware as it would really have been used back in its heyday. Computing really was different before the microcomputer format became mainstream. It’s not the only PDP-11 we’ve seen lately, either! Video after the break.

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Selectric Typewriter Goes From Trash Can To Linux Terminal

July 25, 2023 by 20 Comments

If there’s only lesson to be learned from [alnwlsn]’s conversion of an IBM Selectric typewriter into a serial terminal for Linux, it’s that we’ve been hanging around the wrong garbage cans. Because that’s where he found the donor machine for this project, and it wasn’t even the first one he’s come across in the trash. The best we’ve ever done is a nasty old microwave.

For being a dumpster find, the Selectric II was actually in pretty decent shape. The first couple of minutes of the video after the break show not only the minimal repairs needed to get the typewriter back on its feet, but also a whirlwind tour of the remarkably complex mechanisms that turn keypresses into characters on the page. As it turns out, knowing how the mechanical linkages work is the secret behind converting the Selectric into a teletype, entirely within the original enclosure and with as few modifications to the existing mechanism as possible.

Keypresses are mimicked with a mere thirteen solenoids — six for the “latch interposers” that interface with the famous whiffletree mechanism that converts binary input to a specific character on the typeball, and six more that control thinks like the cycle bail and control keys. The thirteenth solenoid controls an added bell, because every good teletype needs a bell. For sensing the keypresses — this is to be a duplex terminal, after all — [alnwlsn] pulled a page from the Soviet Cold War fieldcraft manual and used opto-interrupters to monitor the positions of the latch interposers as keys are pressed, plus more for the control keys.

The electronics are pretty straightforward — a bunch of MOSFETs to drive the solenoids, plus an AVR microcontroller. The terminal speaks RS-232, as one would expect, and within the limitations of keyboard and character set differences over the 50-odd years since the Selectric was introduced, it works fantastic as a Linux terminal. The back half of the video is loaded with demos, some of which aptly demonstrate why a lot of Unix commands look the way they do, but also some neat hybrid stuff, like a ChatGPT client.

Hats off to [alnwlsn] for tackling a difficult project while maintaining the integrity of the original hardware.

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Typewriter Mashup Becomes 120-Year-Old Teletype

April 5, 2023 by 13 Comments

Vintage typewriters can be beautiful and elegant devices. But there’s a limit to their value if, as with the 1903 Remington owned by [Daniel Ross], they are fire-damaged and have a seized mechanism. What did he do with what was essentially a piece of scrap metal? Produce an unholy mashup of the vintage machine and a 1988 Sharp daisy wheel typewriter to make a steampunk-style teletype, of course!

Stripping down both machines was evidently no easy task, and the result he’s achieved has the Sharp’s printer mechanism at 90 degrees to its original orientation sitting below the roller in the space once occupied by the Remington’s type bars. We’re sad to see that the keyboard on the older machine appears to be inoperable, but on the other hand each letter does light up as it’s typed.

Meanwhile at the electronics side the components from the Sharp have been transferred to a custom PCB, and the whole can be driven from a 300-baud serial line. As can be seen from the video below the break, the result is an unholy love-child of two typewriters that could scarcely be more different, but somehow it works to make an impressive whole.

If this project looks a little familiar to Hackaday readers, it’s because we’ve mentioned it in passing before. It’s hooked up to his COSMAC Elf retrocomputer, and we saw it in passing a couple of years ago at a much earlier stage of construction before the custom PCB and light-up keyboard.

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