The WHY 2025 Badge And Its 18650s

August 12, 2025 by Jenny List 36 Comments

The largest European hacker camp this year was in the Netherlands — What Hackers Yearn (WHY) 2025 is the latest in the long-running series of four-yearly events from that country, and 2025 saw a move from the Flevoland site used by SHA2017 and MCH2021, back to just north of Alkmaar in Noord-Holland, where the OHM2013 event took place. WHY has found itself making the news in the Dutch technical media for all the wrong reasons over the last few days, after serious concerns were raised about the fire safety of its badge.

The cell supplied with a WHY 2025 badge, with very clear fire safety warning — This is the cell supplied with the WHY badge, complete with manufacturer’s warning.

The concerns were raised from the RevSpace hackerspace in Leidschendam, and centre around the design of the battery power traces on the PCB between the battery holders and the power supply circuitry. Because the 18650 cells supplied with that badge lack any protection circuitry, bridging the power traces could be a fire risk.

In short: their report names the cell holders as having tags too large for their pads on the PCB, a too-tight gap between positive and negative battery traces, protected only by soldermask, and the inadequacy of the badge’s short circuit protection. In the event that metal shorted these battery tags, or wore through the soldermask, the batteries would be effectively shorted, and traces or components could get dangerously hot.

The WHY organizers have responded with a printed disclaimer leaflet warning against misuse of the cells, and added a last-minute epoxy coating to the boards to offer additional protection. Some people are 3D-printing cases, which should also help reduce the risk of short-circuiting due to foreign metal objects. Using an external powerbank with short-circuit protection instead of the cells would solve the problem as well. Meanwhile a group of hackers collecting aid for Ukraine are accepting the batteries as donations.

It’s understood that sometimes bugs find their way into any project, and in that an event badge is no exception. In this particular case, the original Dutch badge team resigned en masse at the start of the year following a disagreement with the WHY2025 organizers, so this badge has been a particularly hurried production. Either way, we are fortunate that the issue was spotted, and conference organizers took action before any regrettable incidents occurred.

End Of The Eternal September, As AOL Discontinues Dial-Up

August 11, 2025 by Jenny List 36 Comments

If you used the internet at home a couple of decades or more ago, you’ll know the characteristic sound of a modem connecting to its dial-up server. That noise is a thing of the past, as we long ago moved to fibre, DSL, or wireless providers that are always on. It’s a surprise then to read that AOL are discontinuing their dial-up service at the end of September this year, in part for the reminder that AOL are still a thing, and for the surprise that in 2025 they still operate a dial-up service.

There was a brief period in which instead of going online via the internet itself, the masses were offered online services through walled gardens of corporate content. Companies such as AOL and Compuserve bombarded consumers with floppies and CD-ROMs containing their software, and even Microsoft dipped a toe in the market with the original MSN service before famously pivoting the whole organisation in favour of the internet in mid 1995. Compuserve was absorbed by AOL, which morphed into the most popular consumer dial-up ISP over the rest of that decade. The dotcom boom saw them snapped up for an exorbitant price by Time Warner, only for the expected bonanza to never arrive, and by 2023 the AOL name was dropped from the parent company’s letterhead. Over the next decade it dwindled into something of an irrelevance, and is now owned by Yahoo! as a content and email portal. This dial-up service seems to have been the last gasp of its role as an ISP.

So the eternal September, so-called because the arrival of AOL users on Usenet felt like an everlasting version of the moment a fresh cadre of undergrads arrived in September, may at least in an AOL sense, finally be over. If you’re one of the estimated 0.2% of Americans still using a dial-up connection don’t despair, because there are a few other ISPs still (just) serving your needs.

The Kilopixel Display

August 9, 2025 by Jenny List 6 Comments

Despite the availability of ready-made displays never being better, there are still some hardy experimenters who take on the challenge of making their own. In [Ben Holmen]’s case the display he built is somewhat unusual and not the most practical, but for us a giant-sized wooden kilopixel display is exactly what the world needs.

It’s a kilopixel display because it has a resolution of 40 by 25 pixels, and it takes the form of a rack of wooden cubes, each of which can be turned by a tool on a gantry to expose either a black or a white side. It’s very slow indeed — he has an over nine hour long video of it in operation — but it is an effective device.

His write-up goes into great detail about the steps taken in its design, starting with spherical pixels rotated by a LEGO wheel and progressing to cubes poked at their corner to rotate. The pusher in this case is a hot glue stick, for the required flexibility. For practicality we’re reminded of this serial oil-and-water display.

The whole thing is online, and if you want you can submit your own images for it to draw. Whether a Wrencher in 25 pixel resolution has enough detail, we’ll leave to you.

2025 One Hertz Challenge: Square Waves The Way You Want ‘Em

August 6, 2025 by Jenny List 8 Comments

On an old fashioned bench a signal generator was once an indispensable instrument, but has now largely been supplanted by the more versatile function generator. Sometimes there’s a less demanding need for a clock signal though, and one way that might be served comes from [Rupin Chheda]’s square wave generator. It’s a small PCB designed to sit at the end of a breadboard and provide handy access to a range of clocks.

On the board is a crystal oscillator running at the usual digital clock frequency of 32.768 kHz, and a CMOS divider chain. This provides frequencies from 2048 Hz down to 0.5 Hz for good measure. It’s a simple but oh-so-useful board, and we can imagine more than a few of you finding space for it on your own benches.

This project is part of our awesome 2025 One Hertz Challenge, celebrating all the things which strut their stuff once a second. It’s by no means the first to feature a 32.768 kHz divider chain, and if you have a similar project there’s still time to enter.

Jenny’s Daily Drivers: FreeDOS 1.4

August 6, 2025 by Jenny List 66 Comments

When I was a student, I was a diehard Commodore Amiga user, having upgraded to an A500+ from my Sinclair Spectrum. The Amiga could do it all, it became my programming environment for electronic engineering course work, my audio workstation for student radio, my gaming hub, and much more.

One thing that was part of my course work it couldn’t do very well, which was be exactly like the PCs in my university’s lab. I feel old when I reflect that it’s 35 years ago, and remember sitting down in front of a Tulip PC-XT clone to compile my C code written on the Amiga. Eventually I cobbled together a 286 from cast-off parts, and entered the PC age. Alongside the Amiga it felt like a retrograde step, but mastering DOS 3.3 was arguably more useful to my career than AmigaDOS.

It’s DOS, But It’s Not MS-DOS

The FreeDOS installation screen — Where do I want to go today?

I don’t think I’ve used a pure DOS machine as anything but an occasional retrocomputing curio since some time in the late 1990s, because the Microsoft world long ago headed off into Windows country while I’ve been a Linux user for a very long time. But DOS hasn’t gone away even if Microsoft left it behind, because the FreeDOS project have created an entirely open-source replacement. It’s not MS-DOS, but it’s DOS. It does everything the way your old machine did, but in a lot of cases better and faster. Can I use it as one of my Daily Drivers here in the 2020s? There is only one way to find out.

With few exceptions, an important part of using an OS for this series is to run it on real hardware rather than an emulator. To that end I fished out my lowest-spec PC, a 2010 HP Mini 10 netbook that I hold onto for sentimental reasons. With a 1.6 GHz single core 32 bit Atom processor and a couple of gigabytes of memory it’s a very slow machine for modern desktop Linux, but given that FreeDOS can run on even the earliest PCs it’s a DOS powerhouse. To make it even more ridiculously overspecified I put a 2.5″ SSD in it, and downloaded the FreeDOS USB installer image. Continue reading “Jenny’s Daily Drivers: FreeDOS 1.4” →

2025 One Hertz Challenge: Blinking An LED The Very Old Fashioned Way

August 5, 2025 by Jenny List 10 Comments

Making an LED blink is usually achieved by interrupting its power supply, This can be achieved through any number of oscillator circuits, or even by means of a mechanical system and a switch. For the 2025 One Hertz Challenge though, [jeremy.geppert] has eschewed such means. Instead his LED is always on, and is made to flash by interrupting its light beam with a gap once a second.

This mechanical solution is achieved via a disk with a hole in it, rotating once a second. This is driven from a gear mounted on a 4.8 RPM geared synchronous motor, and the hack lies in getting those gears right. They’re laser cut from ply, from an SVG generated using an online gear designer. The large gear sits on the motor and the small gear on the back of the disk, which is mounted on a bearing. When powered up it spins at 60 RPM, and the LED flashes thus once a second.

We like this entry for its lateral thinking simplicity. The awesome 2025 One Hertz Challenge is still ongoing, so there is still plenty of time for you to join the fun!

Continue reading “2025 One Hertz Challenge: Blinking An LED The Very Old Fashioned Way” →

Happy Birthday 6502

August 4, 2025 by Jenny List 117 Comments

The MOS Technology 6502 is a microprocessor which casts a long shadow over the world of computing. Many of you will know it as the beating heart of so many famous 8-bit machines from the likes of Commodore, Apple, Acorn, and more, and it has retained enough success for a version to remain in production today. It’s still a surprise though, to note that this part is now fifty years old. Though there are several contenders for its birthday, the first adverts for it were in print by July 1975, and the first customers bought their chips in September of that year. It’s thus only fitting that in August 2025, we give this processor a retrospective.

The Moment Motorola Never Really Recovered From

A double page advert for the MOS 6501 and 6502, advertising its low cost and high performance. — The advert that started it all. MOS Technology, Public domain.

The story of the 6502’s conception is a fascinating tale of how the giants of the early mocroprocessor industry set about grappling with these new machines. In the earlier half of the 1970s, Chuck Peddle worked for Motorola, whose 6800 microprocessor reached the market in 1974. The 6800 was for its time complex, expensive, and difficult to manufacture, and Peddle’s response to this was a far simpler device with a slimmed-down instruction set that his contact with customers had convinced him the market was looking for: the 6502.

There’s a tale of Motorola officially ordering him to stop working on this idea, something he would later assert as such an abandonment of the technology that he could claim the IP for himself. Accompanied by a group of his Motorola 6800 colleagues, in the summer of 1974 he jumped ship for MOS Technology to pursue the design. What first emerged was the 6501, a chip pin-compatible with the 6800, followed soon after by the 6502, with the same core, but with an on-board clock oscillator. Continue reading “Happy Birthday 6502” →