Thorium-Metal Alloys And Radioactive Jet Engines

December 16, 2025 by Maya Posch 11 Comments

Although metal alloys is not among the most exciting topics for most people, the moment you add the word ‘radioactive’, it does tend to get their attention. So too with the once fairly common Mag-Thor alloys that combine magnesium with thorium, along with other elements, including zinc and aluminium. Its primary use is in aerospace engineering, as these alloys provide useful properties such as heat resistance, high strength and creep resistance that are very welcome in e.g. jet engines.

Most commonly found in the thorium-232 isotope form, there are no stable forms of this element. That said, Th-232 has a half-life of about 14 billion years, making it only very weakly radioactive. Like uranium-238 and uranium-235 it has the unique property of not having stable isotopes and yet still being abundantly around since the formation of the Earth. Thorium is about three times as abundant as uranium and thus rather hard to avoid contact with.

This raises the question of whether thorium alloys are such a big deal, and whether they justify removing something like historical artefacts from museums due to radiation risks, as has happened on a few occasions.

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After Decades, Linux Finally Gains Stable GPIB Support

December 16, 2025 by Maya Posch 28 Comments

Recently, [Greg Kroah-Hartman] proclaimed the joyous news on the Linux Kernel Mailing List that stable General Purpose Interface Bus (GPIB) support has finally been merged into the 6.19 Linux kernel.

The GPIB is a short-range 8-bit, multi-master interface bus that was standardized as IEEE 488. It first saw use on HP laboratory equipment in the 1970s, but was soon after also used by microcomputers like the Commodore PET, Commodore 64 and others. Although not high-speed with just 8 MB/s, nor with galvanic isolation requirements, it’s an uncomplicated bus design that can be implemented without much of a blip on the BOM costs.

The IEEE 488 standard consists of multiple elements, with 488.1 defining the physical interface and 488.2 the electrical protocol. Over the decades a communication protocol was also developed, in the form of SCPI and its standardized way of communicating with a wide range of devices using a simple human-readable protocol.

Although the physical side of IEEE 488 has changed over the years, with Ethernet becoming a major alternative to the short GPIB cables and large connectors, the electrical protocol and SCPI alike are still very much relevant today. This latest addition to the Linux kernel should make it much easier to use both old and new equipment equipped with this bus.

Building A Commodore 64 Laptop

December 15, 2025 by Maya Posch 17 Comments

What might a laptop version of the Commodore 64 have looked like if one had been released by the late 1980s? This is the question that [Kevin Noki] tried to recently answer with a custom C64 laptop build.

While technically you could argue that Commodore’s SX-64 could be construed as a ‘portable’ system, its bulky format ensured that it was only portable in the sense that a 1980s CRT-based oscilloscope is also portable. Sadly, this turned out to be the last real attempt by Commodore to make a portable non-PC compatible system, with the ill-fated Commodore LCD project never making it out of development. We can, however, glean from this some design hints of what Commodore’s designers had in mind.

Interestingly, [Kevin] decided to instead use the Macintosh Portable as inspiration, with adaptations to make it look more like a breadbin C64. One could have argued that the C64C’s design would have worked better. Regardless, an enclosure was 3D printed, with parts glued together and metal dowels added for support.

For the guts, a custom keyboard with a new PCB and FDM printed keycaps was used, with a Raspberry Pi Pico as keyboard controller. We would here cue the jokes about how the keyboard controller is more powerful than a C64, but the real brains of this laptop come in the form of a Raspberry Pi 5 SBC for running the Vice C64 emulator, which blows a C64 even further out of the water.

This choice also means there’s no direct compatibility with genuine C64 peripherals, but a workaround involving many adaptors and more MCUs was implemented. Sadly, cartridge compatibility was sacrificed due to these complications. The resulting innards can be glimpsed in the above screenshot to give some idea of what the end result looks like.

Of course, this isn’t the first time a Commodore 64 laptop has been created; [Ben Heck] used a C64C mainboard and an original keyboard back in 2009. This meant direct compatibility with all peripherals, including cartridges. Hopefully, now that Commodore as a company has been revived, it will pick up on ideas like these, as an FPGA-based C64 or C128 laptop would be pretty rad.

Thanks to [fluffy] for the tip.

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Printing With PHA Filament As Potential Alternative To PLA

December 14, 2025 by Maya Posch 29 Comments

PLA (polylactic acid) has become the lowest common denominator in FDM 3D printing, offering decent performance while being not very demanding on the printer. That said, it’s often noted that the supposed biodegradability of PLA turned out to be somewhat dishonest, as it requires an industrial composting setup to break it down. Meanwhile, a potential alternative has been waiting in the wings for a while, in the form of PHA. Recently, [JanTec Engineering] took a shot at this filament type to see how it prints and tests its basic resistance to various forms of abuse.

PHA (polyhydroxyalkanoates) are polyesters that are produced by microorganisms, often through bacterial fermentation. Among their advantages are biodegradability without requiring hydrolysis as the first step, as well as UV-stability. There are also PLA-PHA blends that exhibit higher toughness, among other improvements, such as greater thermal stability. So far, PHA seems to have found many uses in medicine, especially for surgical applications where it’s helpful to have a support that dissolves over time.

As can be seen in the video, PHA by itself isn’t a slam-dunk replacement for PLA, if only due to the price. Finding a PHA preset in slicers is, at least today, uncommon. A comment by the CTO of EcoGenesis on the video further points out that PHA has a post-printing ‘curing time’, so that mechanical tests directly after printing aren’t quite representative. Either you can let the PHA fully crystallize by letting the part sit for ~48 hours, or you can speed up the process by putting it in an oven at 70 – 80°C for 6-8 hours.

Overall, it would seem that if your goal is to have truly biodegradable parts, PHA is hard to beat. Hopefully, once manufacturing capacity increases, prices will also come down. Looking for strange and wonderful printing filament? Here you go.

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Teardown Of A 5th Generation Prius Inverter

December 14, 2025 by Maya Posch 5 Comments

The best part about BEV and hybrid cars is probably the bit where their electronics are taken out for a good teardown and comparison with previous generations and competing designs. Case in point: This [Denki Otaku] teardown of a fifth-generation Prius inverter and motor controller, which you can see in the video below. First released in 2022, this remains the current platform used in modern Prius hybrid cars.

Compared to the fourth-generation design from 2015, the fifth generation saw about half of its design changed or updated, including the stack-up and liquid cooling layout. Once [Otaku] popped open the big aluminium box containing the dual motor controller and inverters, we could see the controller card, which connects to the power cards that handle the heavy power conversion. These are directly coupled to a serious aluminium liquid-cooled heatsink.

At the bottom of the Prius sandwich is the 12VDC inverter board, which does pretty much what it says on the tin. With less severe cooling requirements, it couples its heat-producing parts into the aluminium enclosure from where the liquid cooling loop can pick up that bit of thermal waste. Overall, it looks like a very clean and modular design, which, as noted in the video, still leaves plenty of room inside the housing.

Regardless of what you think of the Prius on the road, you have to admit it’s fun to hack.

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Super-Sizing Insects And The Benefits Of Bones

December 12, 2025 by Maya Posch 23 Comments

One swol mealworm amidst its weaker brethren. (Credit: The Thought Emporium, YouTube)

Have you ever found yourself looking at the insects of the Paleozoic era, including the dragonfly Meganeuropsis permiana with its 71 cm wingspan and wondered what it would be like to have one as a pet? If so, you’re in luck because the mad lads over at [The Thought Emporium] have done a lot of the legwork already to grow your own raven-sized moths and more. As it turns out, all it takes is hijacking the chemical signals that control the development phases, to grow positively humongous mealworms and friends.

The growth process of the juveniles, such as mealworms – the larval form of the yellow mealworm beetle – goes through a number of molting stages (instars), with the insect juvenile hormone levels staying high until it is time for the final molt and transformation into a pupa from which the adult form emerges. The pyriproxyfen insecticide is a juvenile hormone analog that prevents this event. Although at high doses larvae perish, the video demonstrates that lower doses work to merely inhibit the final molt.

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NASA May Have Lost The MAVEN Mars Orbiter

December 12, 2025 by Maya Posch 47 Comments

When the orbit of NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft took it behind the Red Planet on December 6th, ground controllers expected a temporary loss of signal (LoS). Unfortunately, the Deep Space Network hasn’t heard from the science orbiter since. Engineers are currently trying to troubleshoot this issue, but without a sign of life from the stricken spacecraft, there are precious few options.

As noted by [Stephen Clark] over at ArsTechnica this is a pretty big deal. Even though MAVEN was launched in November of 2013, it’s a spring chicken compared to the other Mars orbiters. The two other US orbiters: Mars Reconnaissance Orbiter (MRO) and Mars Odyssey, are significantly older by around a decade. Of the two ESA orbiters, Mars Express and ExoMars, the latter is fairly new (2016) and could at least be a partial backup for MAVEN’s communication relay functionality with the ground-based units, in particular the two active rovers. ExoMars has a less ideal orbit for large data transfers, which would hamper scientific research.

With neither the Chinese nor UAE orbiters capable of serving as a relay, this puts the burden on a potential replacement orbiter, such as the suggested Mars Telecommunications Orbiter, which was cancelled in 2005. Even if contact with MAVEN is restored, it would only have fuel for a few more years. This makes a replacement essential if we wish to keep doing ground-based science missions on Mars, as well as any potential manned missions.