If You Like The Sound Of A Thermoacoustic Stirling Engine, Check Out These Plans

March 14, 2026 by Tyler August 2 Comments

[My Engines] has been doing some sterling work on Stirling engines for some years now. Their thermoacoustic engine is now finally far enough along to open-source, so the magic of collaboration can speed technological advancement.

You’ve probably heard of Stirling Engines, but what’s this “thermoacoustic” business? Hot sound? Well, that’s the translation, and it’s not a bad starting point for understanding what’s going on: the engine converts heat into high-amplitude sound waves — that is, waves of pressure — which means the engine itself has no moving parts. Well, almost. Obviously moving parts are required to get power out. In [My Engines] case he’s using a piston and linear generator, but otherwise it makes for a very simple, very reliable engine that can be fueled by any available source of heat. Say like burning methane from [My Engines]’s home biogas plant.

[My Engines] promises more videos to help you understand the construction in a way his previous videos might not detail, and has put 3D models and drawings at a public Google Drive. There’s also a Discord you can join, because apparently that’s the only way to communicate about projects these days.

The whole build is very much within range of a home maker, though there’s a lot more to it than the toy Stirling engines you may have made out of tin cans back in the day. If you want to play with thermoacoustics but [My Engines]’s design seems like a little much to get started with, you can make a demonstrator with some steel wool and a test tube. Be careful, though: model engines can be an addictive hobby.

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The Shockley 4-Layer Diode In 2026

March 14, 2026 by Jenny List 9 Comments

The physicist William Shockley is perhaps today best known for three things: his role in the invention of the transistor, his calamitous management of Shockley Semiconductor which led to a mass defection of employees and precipitated the birth of the Silicon Valley we know, and his later descent into promoting eugenics. This was not the sum of his work though, and [David Prutchi] has been experimenting with a now-mostly-forgotten device that bears the Shockley name (PDF), after finding one used in an early heart pacemaker circuit. His findings are both comprehensive and fascinating.

The Shockley diode, or 4-layer diode as it later became known, is as its name suggests a two terminal device with a 4-layer NPNP structure. It can be modeled as a pair of complementary transistors in parallel with a reverse biased diode, and the avalanche breakdown characteristics of that diode when a particular voltage is applied to it provide the impetus to turn on the two transistors. This makes it a voltage controlled switch, that activates when the voltage across it reaches that value.

The PDF linked above goes into the Shockley diode applications, and in them we find a range of relaxation oscillators, switches, and logic circuits. The oscillators in particular could be made with the barest minimum of components, important in a time when each semiconductor device could be very expensive. It may have faded into obscurity as it was superseded by more versatile 4-layer devices such as the PUJT or silicon-controlled switch and then integrated circuits, but he makes the point that its thyristor cousin is still very much with us.

This appears to be the first time we’ve featured a 4-layer diode, but we’ve certainly covered the genesis of the transistor in the past.

Porting MS-DOS 2.0 To The Apple IIe

March 13, 2026 by Maya Posch 8 Comments

Although the Apple II range of computers were based around the 6502 processor, they could still run x86 software using expansion cards that were effectively self-contained computers. This way an Apple IIe owner, for example, could install an Intel 8088-based AD8088 co-processor card by ALF Products and run CP/M-86 as well as MS-DOS. Unfortunately, as [Seth Kushniryk] discovered while digging into this MS-DOS option, there don’t seem to be any remaining copies of the accompanying MS-DOS 2.0 software.

The obvious response to this is of course to try and port it once again, which [Seth] did. So far he got it to boot, though it’s not quite ready for prime-time yet. Although the AD8088 card is fairly self-contained, it still has to talk with the Apple IIe system, which poses some challenges. To help with the porting he’s using the MS-DOS 2.0 OEM Adaptation Kit that was released along with the sources a while back.

The Apple II has to first load the basic MS-DOS files into the 8088’s RAM before handing over control, which works now along with the basic functionality. Before [Seth] releases the port to the public he still wants to fix a number of issues, in particular the clock. ProDOS on the Apple IIe encodes the year differently than MS-DOS, so that the latter’s clock is off by a few years, and the console driver is still not quite as robust as [Seth] would like it to be.

Beyond this there is also working with the other cards in the Apple II2 system, including the Super Serial Card, and working with the ProDOS filesystem.

Ford, Take Note: Classic Pickup Becomes The EV We Want

March 13, 2026 by Tyler August 45 Comments

Ford does sell an electric pickup, but not very many of them. We can’t say for sure, but it’s possible that if the F150 Lightning had the classic cool of [ScottenMotors] 1977 F150 SuperCab conversion they’d have better numbers.

The battery box sits where a V8 used to choke on well-meaning emissions controls.

On Reddit, [Scotten] shares the takeaways from his conversion effort, which involved a custom Tesla-cell battery pack and a new rear axle assembly to house the Tesla SDU (Small Drive Unit). A Large Drive Unit (LDU) would probably fit, but the SDU already puts out 264 HP, which compares rather favourably to the 156 HP this truck’s malaise-era V8 put out stock. The old F-bodies were great trucks in a lot of respects, but even an die-hard ICE enthusiast is probably not going to be sad to see that motor go.

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Making A Bladeless Tesla Turbine Generator In LEGO

March 13, 2026 by Maya Posch 2 Comments

The Tesla turbine is a bladeless centripetal-flow turbine invented by Nikola Tesla in 1913, using the boundary-layer effect rather than having a stream of gases or a fluid impinge on blades. Recently [Jamie’s Brick Jams] constructed one using LEGO to demonstrate just how well these turbines work compared to their bladed brethren.

Since it uses the boundary-layer effect, the key is to have as much surface area as possible. This means having many smaller discs stacked side by side with some spacing between them.

Interestingly, the air that is directed against the turbine will travel inwards, towards the axle of the discs and thus requiring some way to vent the air. In the video a number of design prototypes are tested to see how they perform before settling on a design suitable for a functional generator.

The first discs are printed in PLA with an FDM printer, which are put on a shaft with 1 mm spacers. What becomes clear during testing is that these turbines can reach ridiculous speeds, but torque is really quite weak until you hit very high RPMs, well beyond 10,000 RPM. This is a bit of an issue if you want to drive any load with it, especially on start-up, but managed to propel a walker robot as a quick torque test.

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No More Paperweight: This Vintage Brick Phone Is Back Online

March 13, 2026 by Matt Varian 16 Comments

Remember those brick cellphones in the 1990s? They were comically large by today’s standards. These phones used the 1G network to communicate and, as such, have been unusable for decades now. However [Alan Boris] has resurrected this classic phone to operate today.

Originally costing as much as today’s top-of-the-line phones, but instead of weighing just a few ounces this classic Motorola DynaTAC 8000 Classic 2 tips the scales at a hefty 1.5 lbs. [Alan Boris] decided to not just bring the electronics back to life, but to even stuff a modern cellphone inside it to make it fully functional. Given the size of this phone, finding room for the new innards wasn’t much of a challenge. In fact, after the retrofit there was less in the phone than when it started life.

Using a perfboard and some tactile switches he was able to sense the button presses on the phone’s keypad and relay those to a Raspberry Pi Pico 2. The Pico in turn drove a small color LCD to replicate the original screen and controlled a pair of ADG729 boards used to dial the BM10 cellphone within this cellphone. The BM10 is a cellphone about the size of a 9V battery, making it easy to put inside the DynaTAC and bring the handset back to the modern cellular network.

Thanks [Alan Boris] for the tip! Be sure to check out our other cellphone hacks as well as some of our other retrofit hacks.

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Hackaday Podcast Episode 361: Hackaday Podcast Mailbag, A Phone Is Not A Computer, 3D Printing History Is New Again

March 13, 2026 by Tom Nardi 1 Comment

Join Hackaday Editors Elliot Williams and Tom Nardi as they cover their favorite hacks and stories from the week. The episode kicks off with some updates about Hackaday Europe and the recently announced Green Power contest, as well as the proposal of a new feature of the podcast where listeners are invited to send in their questions and comments. After the housekeeping is out of the way, the discussion will go from spoofing traffic light control signals and the line between desktop computers and smartphones, all the way to homebrew e-readers and writing code with chocolate candies. You’ll hear about molding replacement transparent parts, a collection of fantastic tutorials on hardware hacking and reverse engineering, and the recent fireball that lit up the skies over Germany. The episode wraps up with a fascinating look at how the developer of Pokemon Go is monetizing the in-game efforts of millions of players.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download this episode in DRM-free MP3 so you can listen to it while doing unpaid labor in Pokemon Go.