Tefifon: Germany’s Tape-Shaped Record Format

August 28, 2025 by Maya Posch 15 Comments

A Tefifon cartridge installed for playback. (Credit: Our Own Devices, YouTube)

Recently the [Our Own Devices] YouTube channel took a gander at the Tefifon audio format. This was an audio format that competed with shellac and vinyl records from the 1930s to the 1960s, when the company behind it went under. Some people may already know Tefifon as [Matt] from Techmoan has covered it multiple times, starting with a similar machine about ten years ago, all the way up to the Stereo Tefifon machine, which was the last gasp for the format.

There’s a lot to be said for the Tefifon concept, as it fixes many of the issues of shellac and vinyl records, including the limited run length and having the fragile grooves exposed to damage and dust. By having the grooves instead on a flexible band that got spooled inside a cartridge, they were protected, with up to four hours of music or eight hours of spoken content, i.e. audio books.

Although the plastic material used for Tefifon bands suffered from many of the same issues as the similar Dictabelt audio recording system, such as relatively rapid wear and degradation (stiffening) of the plastic, it was mostly the lack of interest from the audio labels that killed the format. With the big labels and thus big artists heavily invested in records, the Tefifon never really got any hits and saw little use outside of West Germany throughout the 1950s and 1960s before its last factories were shuttered.

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The Browser Wasn’t Enough, Google Wants To Control All Your Software

August 28, 2025 by Tom Nardi 170 Comments

A few days ago we brought you word that Google was looking to crack down on “sideloaded” Android applications. That is, software packages installed from outside of the mobile operating system’s official repository. Unsurprisingly, a number of readers were outraged at the proposed changes. Android’s open nature, at least in comparison to other mobile operating systems, is what attracted many users to it in the first place. Seeing the platform slowly move towards its own walled garden approach is concerning, especially as it leaves the fate of popular services such as the F-Droid free and open source software (FOSS) repository in question.

But for those who’ve been keeping and eye out for such things, this latest move by Google to throw their weight around isn’t exactly unexpected. They had the goodwill of the community when they decided to develop an open source browser engine to keep the likes of Microsoft from taking over the Internet and dictating the rules, but now Google has arguably become exactly what they once set out to destroy.

Today they essentially control the Internet, at least as the average person sees it, they control 72% of the mobile phone OS market, and now they want to firm up their already outsized control which apps get installed on your phone. The only question is whether or not we let them get away with it.

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Picture By Paper Tape

August 26, 2025 by Al Williams 14 Comments

The April 1926 issue of “Science and Invention” had a fascinating graphic. It explained, for the curious, how a photo of a rescue at sea could be in the New York papers almost immediately. It was the modern miracle of the wire photo. But how did the picture get from Plymouth, England, to New York so quickly? Today, that’s no big deal, but set your wayback machine to a century ago.

Of course, the answer is analog fax. But think about it. How would you create an analog fax machine in 1926? The graphic is quite telling. (Click on it to enlarge, you won’t be disappointed.)

If you are like us, when you first saw it you thought: “Oh, sure, paper tape.” But a little more reflection makes you realize that solves nothing. How do you actually scan the photo onto the paper tape, and how can you reconstitute it on the other side? The paper tape is clearly digital, right? How do you do an analog-to-digital converter in 1926? Continue reading “Picture By Paper Tape” →

Where There Is No Down: Measuring Liquid Levels In Space

August 26, 2025 by Dan Maloney 40 Comments

As you can probably imagine, we get tips on a lot of really interesting projects here at Hackaday. Most are pretty serious, at least insofar as they aim to solve a specific problem in some new and clever way. Some, though, are a little more lighthearted, such as a fun project that came across the tips line back in May. Charmingly dubbed “pISSStream,” the project taps into NASA’s official public telemetry stream for the International Space Station to display the current level of the urine tank on the Space Station.

Now, there are a couple of reactions to a project like this when it comes across your desk. First and foremost is bemusement that someone would spend time and effort on a project like this — not that we don’t appreciate it; the icons alone are worth the price of admission. Next is sheer amazement that NASA provides access to a parameter like this in its public API, with a close second being the temptation to look at what other cool endpoints they expose.

But for my part, the first thing I thought of when I saw that project was, “How do they even measure liquid levels in space?” In a place where up and down don’t really have any practical meaning, the engineering challenges of liquid measurement must be pretty interesting. That led me down the rabbit hole of low-gravity process engineering, a field that takes everything you know about how fluids behave and flushes it into the space toilet.

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Radio Apocalypse: America’s Doomsday Rocket Radios

August 25, 2025 by Dan Maloney 17 Comments

Even in the early days of the Cold War, it quickly became apparent that simply having hundreds or even thousands of nuclear weapons would never be a sufficient deterrent to atomic attack. For nuclear weapons to be anything other than expensive ornaments, they have to be part of an engineered system that guarantees that they’ll work when they’re called upon to do so, and only then. And more importantly, your adversaries need to know that you’ve made every effort to make sure they go boom, and that they can’t interfere with that process.

In practical terms, nuclear deterrence is all about redundancy. There can be no single point of failure anywhere along the nuclear chain of command, and every system has to have a backup with multiple backups. That’s true inside every component of the system, from the warheads that form the sharp point of the spear to the systems that control and command those weapons, and especially in the systems that relay the orders that will send the missiles and bombers on their way.

When the fateful decision to push the button is made, Cold War planners had to ensure that the message got through. Even though they had a continent-wide system of radios and telephone lines that stitched together every missile launch facility and bomber base at their disposal, planners knew how fragile all that infrastructure could be, especially during a nuclear exchange. When the message absolutely, positively has to get through, you need a way to get above all that destruction, and so they came up with the Emergency Rocket Communication System, or ERCS.

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Ask Hackaday: Where Are All The Fuel Cells?

August 21, 2025 by Tom Nardi 60 Comments

Given all the incredible technology developed or improved during the Apollo program, it’s impossible to pick out just one piece of hardware that made humanity’s first crewed landing on another celestial body possible. But if you had to make a list of the top ten most important pieces of gear stacked on top of the Saturn V back in 1969, the fuel cell would have to place pretty high up there.

Apollo fuel cell. Credit: James Humphreys

Smaller and lighter than batteries of the era, each of the three alkaline fuel cells (AFCs) used in the Apollo Service Module could produce up to 2,300 watts of power when fed liquid hydrogen and liquid oxygen, the latter of which the spacecraft needed to bring along anyway for its life support system. The best part was, as a byproduct of the reaction, the fuel cells produced drinkable water.

The AFC was about as perfectly suited to human spaceflight as you could get, so when NASA was designing the Space Shuttle a few years later, it’s no surprise that they decided to make them the vehicle’s primary electrical power source. While each Orbiter did have backup batteries for emergency purposes, the fuel cells were responsible for powering the vehicle from a few minutes before launch all the way to landing. There was no Plan B. If an issue came up with the fuel cells, the mission would be cut short and the crew would head back home — an event that actually did happen a few times during the Shuttle’s 30 year career.

This might seem like an incredible amount of faith for NASA to put into such a new technology, but in reality, fuel cells weren’t really all that new even then. The space agency first tested their suitability for crewed spacecraft during the later Gemini missions in 1965, and Francis Thomas Bacon developed the core technology all the way back in 1932.

So one has to ask…if fuel cell technology is nearly 100 years old, and was reliable and capable enough to send astronauts to the Moon back in 1960s, why don’t we see them used more today?

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Death Of The Cheque: Australia Moves On

August 20, 2025 by Lewin Day 108 Comments

Check (or cheques) have long been a standard way for moving money from one bank account to another. They’re essentially little more than a codified document that puts the necessary information in a standard format to ease processing by all parties involved in a given transaction.

The check was once a routine, if tedious, way for the average person to pay for things like bills, rent, or even groceries. As their relevance continues to wane in the face of newer technology, though, the Australian government is making a plan to phase them out for good.

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