Articles by Jenny List

In the decade-and-a-bit since the first Raspberry Pi was launched we’ve seen an explosion of affordable single-board computers (SBCs), but as the prices creep up alongside user expectation and bloat, [Christopher Barnatt] asks where the industry will go next.
The Pi started with an unbeatable offer, $35 got you something similar to the desktop PC you’d had a decade earlier — able to run a Linux desktop on your TV from an SD card. Over the years the boards have become faster and more numerous, but the prices for ARM boards are now only nominally as affordable as they were in 2012, and meanwhile the lower end of x86 computing is now firmly in the same space. He demonstrates how much slower the 2023 Raspberry Pi OS distribution is on an original Pi compared to one of the early pre-Raspbian distros, and identifies in that a gap forming between users. From that he sees those people wanting a desktop heading towards the x86 machines, and the bare-metal makers at the lower end heading for the more powerful microcontrollers which simply weren’t so available a decade ago.
We have to admit that we agree with him, as the days when a new Raspberry Pi board was a special step forward rather than just another fast SBC are now probably behind us. In that we think the Pi people are probably also looking beyond their flagship product, as the hugely successful lunches of the RP2040 and the industrial-focused Compute Module 4 have shown.
What do you think about the SBC market? Tell us in the comments.

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The noise of a dot matrix printer is probably as synonymous with 1980s computing as the modem handshake would become with the desktop experience a decade or more later. But unlike the computers that would have driven it, a dot matrix printer can still be a very useful device here in 2023. And why not? They’re cheap to operate and can produce surprisingly good quality when paired with suitable drivers. There is a snag though; while cartridges for popular models can still be found, there are plenty whose consumables are long gone. [Drygol] had an Apple ImageWriter II with exactly that problem, and after finding all his cartridges were non-functional, took a look at how to bring them back.
Inside a dot matrix cartridge is a fabric ribbon similar to the one that might once have been found on a typewriter. It’s not on a roll but folded into the space, and it’s drawn through by a pair of rollers. Not only had the ink on the fabric dried out, but the foam on the rollers had also disintegrated. Some careful dismantling, and a solution presented itself in the form of O-rings to replace the rollers. Those and a bit of mineral oil to soften the ink had the vintage Apple printing again as though it was the ’80s once more.
It’s a subject we’ve looked at before, as it turns out WD-40 makes a good ink solvent. […]

Some of the world’s largest radio telescopes are not in fact as physically large as they claim to be, but instead are a group of telescopes spread over a wide area whose outputs are combined to produce a virtual telescope equal in size to the maximum distance between the constituents of the array. Can this be done on the cheap with an array of satellite dishes? It’s possible, but as [saveitforparts] found out when combining a set of Tailgater portable dishes, not simply by linking together the outputs from a bunch of LNBs.
The video below the break still makes for an interesting investigation and the Tailgater units are particularly neat. It prompted us to read up a little on real aperture synthesis, which requires some clever maths and phase measurement for each antenna. Given four somewhat more fancy LNBs with phase-locked local oscillators and an software-defined radio (SDR) for each one then he might be on to something.
If you’re curious about the cyberdeck in the video, you might like to read our coverage of it. And the Tailgater might be a bit small, but you can still make a useful radio telescope from satellite TV parts.

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People trying to preserve digital artifacts held on old media often not only have to contend with the media themselves decaying, but also with obscure media formats for which there’s seemingly little chance of finding a working reader. [Kneesnap] had this problem with a tape containing the only known copy of all the assets for the game Frogger 2: Swampy’s Revenge, and the tale of how the data was recovered is a dive into both the shady side of the data recovery industry and some clever old-format hacking.
The tape was an Onstream cartridge, a short-lived format from a company whose first product hit the market at the end of the ’90s and who went bust in 2004. An old drive was found, but it proved to have a pinch roller melted with age, so in desperation the tape was sent to a data recovery company.
We admire the forbearance in not naming and shaming the data recovery company, because far from recovering the data they sent it back with the tape damaged and spliced — something you can do with an analogue tape but not a digital one without compromising the data. Then faced with an unrecoverable tape and a slightly different Onstream cartridge, how could anything be salvaged?
The answer came in overriding the drive’s sensors and initializing it with a known-good tape, then swapping out the tapes so that the drive, unaware anything had changed, could read whatever data it could find. In the event the vast majority of the archive was retrieved, making it a win for the preservation of that game.
This may be more involved than some recovery stories, but it’s not the first we’ve covered. […]

We’re guessing that quite a few of our readers have a surprising amount of redundant test gear, and we ourselves have to admit that more than one instrument adorns our benches. But we are mere dilettantes, amateurs if you will, compared to [Volke Kloke]. He’s got 350 of them in his average American home, and we have to say, among them are some beauties.
The linked newspaper article is sometimes frustratingly light on the details, but fortunately he has a website all of his own where we can all get immersed in the details. Of particular interest is an instrument which doesn’t even have a CRT, the General Radio 338 string oscillograph used a mirror drum to catch a standing wave in a tungsten wire, but there are plenty more. Is your first ‘scope among them?
As we now live in the age of cheap digital ‘scopes, at any surplus sale you’ll see plenty of CRT-based instruments going for relative pennies. Of those, the more recent and high-end ones are still extremely useful instruments, and it’s not just misty-eyed reminiscing to say that they remain a worthy addition to any bench.
Want to know about early ‘scope tech? We’ve taken a look before. […]

The Holy Grail of battery technology is a cell which lasts forever, a fit-and-forget device that never needs replacing. It may seem a pipe-dream, but University of Bristol researchers have come pretty close. The catch? Their battery lasts a very long time, but it generates micropower, and it’s radioactive.
They’re using a thin layer of vapour-deposited carbon-14 diamond both as a source of beta radiation, and as a semiconductor material which harvests those electrons. They’re expected to be used for applications such as intermittent sensors, where they would slowly charge a supercapacitor which could release useful amounts of power in short bursts.
It’s being touted as an environmental win because the carbon-14 is sourced from radioactive waste, but against that it’s not unreasonable to have a concern about the things being radioactive. The company commercializing the tech leads with the bold question: “What would you do with a power-cell that outlasts the device it powers?“, to which we would hope the answer won’t be “Throw it away to be a piece of orphaned radioactive waste in the environment when the device it powers is outlasted”. We’ll have to wait and see whether devices containing these things turn up on the surplus market in a couple of decades.
Fortunately the carbon-14 lives not in cartoonish vats of radioactive green slime but safely locked away in diamond, about the safest medium for it to be in. The prototype devices are also tiny, so we’re guessing that the quantity of carbon-14 involved is also small enough to not be a problem. We’re curious though whether they could become a valuable enough commodity to be reused and recycled in themselves, after all something that supplies energy for decades could power several different devices over its lifetime. Either way, it’s a major improvement over a tritium cell. […]

Dear Ubuntu,
I hope this letter finds you well. I want to start by saying that our time together has been one of creativity and entertainment, a time in which you gave me the tools to develop a new career, to run a small electronics business, make fun things, and to write several thousand articles for Hackaday and other publications, but for all that it’s sadly time for our ways to part. The magic that once brought us together has faded, and what remains is in danger of becoming a frustration.
In our early days as an item you gave me for the first time a Linux distro that was complete, fast, and easy to use without spending too much time at the CLI or editing config files to make things happen; you gave me a desktop that was smooth and uncluttered, and you freed me from all those little utilities that were required to make Windows usable. You replaced the other distros I’d been using, you dual-booted with my Windows machines, and pretty soon you supplanted the Microsoft operating system entirely.
Me and Ubuntu in 2017, good times.
We’ve been together for close to two decades now, and in that time we’ve looked each other in the eye across a variety of desktop and laptop computers. My trusty Dell Inspiron 640 ran you for over a decade through several RAM, HDD, and SSD upgrades, and provided Hackaday readers with the first few years of my writing. Even the Unity desktop couldn’t break our relationship, those Linux Mint people weren’t going to tear us asunder! You captured my text, edited my videos and images, created my PCBs and CAD projects, and did countless more computing tasks. Together we made a lot of people happy, and for that I will always be grateful.
This dialogue has been an unwelcome guest rather a lot of late.
But over the last few years, I’ve noticed that our relationship has slowly become one less of harmony and more of frustration. Like middle-aged spread, you became progressively more bloated, your moments of freezing became obvious and inconvenient, and the delays to open some indispensable pieces of software became too long to simply explain as the result of having other apps running in the background. Our once close relationship has become strained by endless waiting for Snap packaged applications to load, and by my USB peripherals mysteriously refusing to talk to applications they’ve been used with for years.
I understand that Snap is meant to release us from dependency hell and I know why you’ve put each one in its own little sandbox, but honestly, even ChromeOS running a Linux application in its virtual machine is faster than this, and it doesn’t require everything to come from one distribution hub, or mess with access to hardware. I need my machine’s performance back, I need using a peripheral to stop being a lottery. I need more, Ubuntu, I need a distro that understands me and works with me, not against me!
I’ve tried to work around my frustrations, tried to convince myself that maybe if I had a faster laptop we could be happy together, but I can’t help thinking about the older generation PC in my hackerspace running Arch that Just Works, and Just Works without having to wait several minutes for Prusa Slicer to load. I realise that I can’t go on living a lie, I need to move on and find a distro that gives me the performance and stability I crave.
I need you to know that I didn’t jump to this conclusion in an instant. I kept the faith, I kept hoping every fresh distribution update would fix your shortcomings, and I even defended you when confronted with the other, leaner, distros my friends use. But I sense we’ve passed the point of no return, and a relationship built on frustration is no way to live. Let’s remember the good times, writing an article lying in a hammock at BornHack, or cracking how to number-crunch millions of words of corpus text on a mundane laptop. We traveled a long way together, and for that I’m grateful.
The transition will be painless enough, I won’t even uninstall you. Instead I have a new SSD in the mail, and I’ll transfer you in your drive to your own caddy. We’ll still see each other from time to time, and maybe if you can Snap out of your midlife crisis one day we’ll get back together. Meanwhile, thanks for all the good things you allowed me to do over the years, and I hope your maintainers can help you through your current difficulties.
Yours,

Jenny List […]

We’ve seen the 1993 id Software classic DOOM running on so many pieces of unexpected hardware, as “Will it run DOOM?” has become something of a test for any new device. But will it run in the circuitry of a 1970s or 1980s TV set? Not quite, but as [lukneu] has demonstrated, it is possible to render the game using the set’s inbuilt Teletext decoder.
Teletext is a technology past its zenith and which is no longer broadcast in many countries, but for those unfamiliar it’s an information service broadcast in the unseen lines hidden in the frame blanking period of an analogue TV transmission. Its serial data packets can contain both pages of text and rudimentary block graphics, and we’re surprised to learn, can include continuous streams to a single page. It’s this feature that he’s used, piping the game’s graphics as a teletext stream which is decoded by the CRT TV and displayed as a playable if blocky game.
Delving further, we find that DOOM is running on a Linux machine on which the teletext stream is created, and the stream is then piped to a Raspberry Pi which does the encoding on to its composite video output. More powerful versions of the Pi can run both processes on the same machine. The result can be seen in the video below, and we can definitely say it would have been mind-blowing, back when DOOM was king. There are plans for further refinement, of which we’d say that color would be the most welcome.

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Getting a job has always been a tedious and annoying process, as for all the care that has been put into a CV or resume, it can be still headed for the round file at the whim of some corporate apparatchik. At various times there have also been dubious psychometric tests and other horrors to contend with, and now we have the specter of AI before us. We can be tossed aside simply because some AI model has rejected our CV, no human involved. If this has made you angry, perhaps it’s time to look at [Kai Greshake]’s work. He’s fighting back, by injecting a PDF CV with extra text to fool the AI into seeing the perfect candidate, and even fooling AI-based summarizers.
Text injection into a PDF is a technique the same as used by the less salubrious end of the search engine marketing world, of placing text in a web page such that a human can’t read it but a machine can. The search engine marketeers put them in tiny white text or offset them far out of the viewport, and it seems the same is possible in a PDF. He’s put the injection in white and a tiny font, and interestingly, overlaid it several times.
Using the ChatGPT instance available in the Bing sidebar he’s then able to fool it into an affirmative replay to questions about whether he should be hired. But it’s not just ChatGPT he’s targeting, another use of AI in recruitment is via summarizing tools. By injecting a lot of text with phrases normally used in conclusion of a document, he’s able to make Quillbot talk about puppies. Fancy a go yourself? He’s put a summarizer online, in the link above.
So maybe the all-seeing AI isn’t as clever as we’ve been led to believe. Who’d have thought it! […]