Mysterious Files PH

Although the demise of the Zilog Z80 processor has long been predicted, it would seem that this moment has finally arrived. The owner of the Zilog name – Littelfuse – recently sent out PCN ZAC26-0074, notifying customers that they will be taking final orders for the eZ80 and all other microcontroller lines that they currently own.

Over at Mouser, eZ80 parts have correspondingly all been marked as “End of Life”. This comes a few years after the original Z80 and its peripherals were discontinued, with the eZ80 still being an alternative until now.

Any potential sellers will have to put in their orders today, with orders still accepted until December 21 2026, with final deliveries taking place throughout 2027 as Littelfuse winds down its MCU manufacturing. This means that for commercial customers are least this is pretty much the end of the road for any circuit that still uses the eZ80 or similar.

Many of us have fondness for the Z80, which also has led to a potential way that the Z80 can live on. This includes both the many open source cores that are compatible with the Z80, as well as real silicon courtesy of the TinyTapeout project.

Thanks to [Techokami] for the tip.

Atomic clocks are super accurate. But, unsurprisingly, some atomic clocks are better than others, depending on your definition of better. Researchers at Vienna University claim to have a superior thorium-based atomic clock. It isn’t necessarily more accurate than other atomic clocks, but it is self-regulating.

Apparently, prior atomic clocks need help to stay stable. But scientists have thought that thorium, with its very narrow gap between two states, would make an excellent clock with the help of a laser. However, the laser has to have precise properties that, at least in early experiments, were provided by another nuclear clock.

Obviously, you’d like to be able to use a laser to excite the source — a thorium crystal in this case — and then use the output of that to adjust the laser. That’s apparently what the team has done. If the laser drifts, the thorium nuclei absorb less light, and that adjusts the output frequency to compensate. If you can follow the physics, you can read the source paper in Nature.

Optical atomic clocks are the way to go for time standards, but this research has promise to provide even more accurate results in the future.

The Abric Romaní site in Spain is rather unique in archeology for one simple reason: the caves in its limestone-rich cliff have seen humanoid occupation for thousands of years. A thick layer of calcium carbonate-based travertine deposit has, over time, covered and largely preserved tools and other implements, including those made of wood. Over many decades of archeological exploration, 597 wooden imprints have been uncovered, with a recent research article by [Palmira Saladié] et al. detailing these findings.

Wood is one of those archaeological artefacts that are very elusive due to their fragility, even though we know that wood has been used pretty much everywhere from the first day that a humanoid critter discovered that branches make great clubs and spears, and can also easily be shaped to make them even more useful.

The wooden imprints and some larger remains of wooden implements were found, ranging from wooden spears and clubs to trays (see heading image) and tripods. With enough of the wood still present, researchers were also able to determine which types of trees were used to make these tools, and sometimes which part of the tree.

These finds date back to between 62,000 and 40,000 years ago during the Middle Paleolithic era. This would have been around the time that Homo sapiens began to move into Europe, with both species of humans living side by side for thousands of years. These days, the only active traces of this can be found in our DNA, which retains bits of H. neanderthalensis.

The supplemental materials PDF  breaks down some of this site’s more recent history. The sole reason that this crucial archaeological site was discovered was that the landowner in the early 20th century expressed a profound interest in archaeology and other natural sciences.

Thanks to this lucky find, we gained some insight into how our ancestors would have learned how to create crude wooden implements, before eventually moving on to smelting metals and eventually sand in order to make it into computer chips.

Although the asking price of $209 plus shipping seems high for the Radxa Dragon Q8B, featuring the Qualcomm SC8280XP and 8 GB of LPDDR4X, this is 2026, and amid the RAMpocalypse, even the 8 GB LPDDR4X-equipped Raspberry Pi 5 now costs $175. This, to [Jeff Geerling], makes it fair to directly compare the two to see whether you may want to consider this board for more intense computing purposes.

There’s also a written summary of the results and details in a GitHub issue, though the direct comparison with the Raspberry Pi 5 is in the video.

Although this Qualcomm SoC isn’t new, its primary use is for Windows laptops, which gives somewhat of a hint as to what its performance may be like, tempered by the fact that it was announced in 2021.

The Dragon QXB offers about 2x everything over the RPi5, plus Windows and UEFI support. For Linux, it appears that you still need customized images, which seems perplexing in light of the UEFI aspect. You also have to pick between different Linux images from Radxa and use their Rsetup update tool, making it a less than ewbie-friendly offering.

The Radxa-provided Linux experience is somewhat choppy. Raw performance in e.g., Geekbench 6 multi-core shows why you’d want to use this SBC, as it triples the RPi5 score. Power efficiency is also better, with [Jeff]’s HPL efficiency showing 3.73 Gflops/W versus 2.75 for the RPi5. There are twin 2.5 Gbit Ethernet ports and more PCIe too, all of which can really be used by the raw CPU power.

This means that there’s a lot to like about this Q8B SBC. [Jeff] expresses his appreciation for it, despite issues with the Radxa UEFI BIOS. It feels like Radxa is still trying to work out the BIOS-related kinks, which might even allow for the installation of generic OS images, rather than their own images.

Per the documentation, the SBC comes in a range of RAM sizes, from 4 to 32 GB, so you can still get a cheaper version too, if you can find one for sale. As noted in the video, these SBCs are still pretty scarce, and as the AI-induced personal computing and SBC collapse continues, this situation is unlikely to improve.

Valve recently began shipping its long-awaited VR headset, the Steam Frame. Now, there is a hardware reference repository that includes everything a budding modder might need, and then some.

Want to design and 3D print some add-ons, or a carrying case, or some other doodad? There’s no need to break out the calipers or 3D scan the hardware. The repository contains STEP format models of the VR core module, head strap, and controllers, so it’s as easy as possible to design things that’ll fit. The location of the IR tracking LEDs embedded in the controllers is also documented, so one can ensure their design doesn’t occlude them.

That’s not all. The Frame has a user-accessible hardware expansion port at its front. This port exposes two interfaces: high-speed MIPI camera and PCI Express. This expansion port is documented in the repository, and even has a simple reference design built in both KiCad and Altium.

We’re glad to see Valve maintain their hacker-friendly hardware design with the Steam Frame. Demand for The Frame outstrips supply so far, so if you’re on the waitlist, you might want to browse the repository and get an early start on whatever customizations you have in mind while you wait for your confirmation. And when you get something working, drop us a note on the tips line!

Finding inexpensive broken hardware for sale, buying it, and restoring it to working condition is a long-standing tradition for hackers on a limited budge. But there are some devices that are so difficult to repair that it’s usually not worth the trouble. [Vintage560] is braver than most, though, and restored an internally-damaged Casio AW-330-AT altimeter watch.

The exterior of the watch was in good condition, other than missing a readily-replaced strap, but the battery had leaked into the interior, and the watch didn’t respond in any way to new batteries. Cleaning out the guts with isopropyl alcohol, repositioning a plastic insulator, and bending some contacts back into shape at least got some segments of the LCD display to activate, while over two days of turning the crown smoothed out resistance in the analog train.

Actually getting the LCD to work properly required disassembling the watch, taking particular care with the altitude sensor. It wasn’t clear what was wrong with the LCD — the controller seemed to be working properly, and several rounds of cleaning and adjusting the ZEBRA connector didn’t make any difference.

Eventually, [Vintage560] simply purchased a new screen. On close inspection, it looked as though chemicals from the leaking battery might have dissolved some of the transparent indium tin oxide contacts on the old display. With the watch now working [Vintage560] tested it on a trip to the Alps, and with a few periodic calibrations, it remained quite accurate.

Usually when we see Casio watch hacks, the watch in question is the F91W, whether it’s being used for contactless payments, being retrofitted as a smartwatch, or going 5,000 meters underwater.

Recently [Riley] got his paws on an old Prusa i3 FDM printer that had clearly seen better days, with a hot-end that had suffered an explosive blow-out. For the project he had in mind this was of course perfect, as his intention was to replace the hot-end with a syringe system for embedded 3D printing (E3DP), which uses a supportive medium to allow for the printing of materials and structures that would be impossible with just air.

Generally in additive manufacturing (AM) methods like fused deposition modelling (FDM) the material is extruded onto a build plate or a previous layer where it solidifies. This works great for materials like thermoplastics, but for other materials having only the surrounding air as support is just a recipe for a big mess. With E3DP the liquid is instead extruded into a supportive material at a selectable depth and volume, opening up a whole range of possibilities.

In a 2026 review article by [Rongji Tang] et al. in Frontiers in Materials provide an overview of the state-of-the-art in E3DP, including many ongoing research questions pertaining to print quality, the types of supportive material and their potential reuse, as well as extrusion control. Applications for E3DP are many, with it seeing use in flexible- and soft robotics, printing biological tissues and microfluidics.

While some types of fluids are easier to print than others, Newtonian fluids like silicone oil pose issues with reliable printing, as detailed by [Hejoon Jun] et al. in a 2025 paper in Applied Materials & Interfaces, while a 2026 paper by [Min Ye] et al. in International Journal of Extreme Manufacturing covers the challenges of printing living tissues this way, with a self-healing supporting medium described, creating a method called EPICS.

In the video by [Riley] the fundamentals are explained in a comprehensive manner, before building an E3DP setup, with an open source Allstruder syringe pump and a Caribou Duet 3 motherboard replacing the Prusa parts. Following this a test print is made using cream cheese as it’s apparently an ideal test material.

After a successful cream cheese test, a print is started involving two-part epoxy, with the supporting material being hair gel. The epoxy, once mixed, has only a time window of about forty minutes before it hardens, so that’s all the time you have to empty the syringe. As it turns out, hair gel and epoxy aren’t friends, so for a final print the printing material was switched to silicone, specifically Sylgard 184.

Although not a perfect result, it’s pretty cool to see the silicone trifold torus take shape in what appears to be a void. Unfortunately the hair gel doesn’t appear to be a perfect material either, as some of the additives in it apparently inhibit the silicone from curing. As reported by [Riley] in a comment to the video, the silicone print was still goopy after a few days.

We hope that it’ll cure before long, and wish him luck in finding a supporting material that’s more supportive of printing materials like silicone actually curing.