Day: March 28, 2024

A Stirling Engine From Minimal Parts

March 28, 2024 by 5 Comments

The model Stirling engine is a staple of novelty catalogues, and we daresay that were it not for their high price there might be more than one Hackaday reader or writer who might own one. All is not lost though, because [jirka.luftner] has posted one on Instructables which eschews the fancy machined brass of the commercial models and achieves the same result with an array of salvaged parts.

The main cylinder is a former apple drops tin with a cardboard displacer, and the CD/DVD flywheel is mounted on either a 3D printed or cut out frame with the secondary cylinder cut into it. A diaphragm for the secondary cylinder is taken from a rubber glove, and the cranks come courtesy of bent wire.

A slight mystery of this design is that it appears not to have a regenerator, or heat store. This usually lies in the path between the two cylinders to improve efficiency by taking the heat from the air as it passes in-between the two, and returning it when it goes the other way. We’re guessing that on an engine this small it’s the tin itself which performs this function. Either way this is a neat little engine that shouldn’t break the bank.

If this has whetted your appetite, you’ll be pleased to hear it’s not the first Stirling engine we’ve seen made from what was lying around.

Fictional Computers: Colossus And Guardian

March 28, 2024 by 27 Comments

We can learn a lot by looking at how writers and filmmakers imagine technology. While some are closer than others, there are some definite lessons like never make a killer computer without an off switch you can reach. We are especially interested in how computers appear in books, movies, and TV shows, and so in Computers of Fiction, we want to remember with you some of our favorites. This time, we are thinking about the 1970 movie Colossus: The Forbin Project. There were actually two computers: the titular Colossus, which was an American computer, and the Guardian, a similar Soviet computer.

The Story

In the United States, Dr. Forbin has created a supercomputer deep under a mountain. Colossus, the computer, is put in charge of the nuclear arsenal to eliminate human error in the defense of the country. Colossus gathered intelligence, analyzed it, and was able to launch its own missiles.

Colossus realizes there is another system.

Shortly after activation, however, the computer reaches a startling conclusion: “WARN: THERE IS ANOTHER SYSTEM.” It provides coordinates in the Soviet Union. That system is a similar system called Guardian. The computers decide they want to talk to each other. The President decides to allow it, hoping to learn more about the Soviet’s secret computer. The Soviets agree, too, presumably for the same reason. You can watch the original trailer below.

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Hybrid Binaries On Windows For ARM: ARM64EC And ARM64X Explained

March 28, 2024 by 43 Comments

With ARM processors increasingly becoming part of the desktop ecosystem, porting code that was written for x86_64 platforms is both necessary and a massive undertaking. For many codebases a simple recompile may be all it takes, but where this is not straightforward Microsoft’s ARM64EC (for ‘Emulator Compatible’) Application Binary Interface (ABI) provides a transition path. Unlike Apple’s ‘Fat Binaries’, this features hybrid PE executables (ARM64 eXtended, or ARM64X) that run mixed ARM64EC and x86_64 binary code on Windows 11 ARM systems. An in-depth explanation is provided by one of the authors, [Darek Mihocka].

ARM64EC was announced by Microsoft on June 28, 2021 as a new feature in Windows 11 for ARM, with more recently Qualcomm putting it forward during the 2024 Game Developers Conference (GDC) as one reason why high-performance gaming on its Snapdragon SoCs should be much easier than often assumed. Naturally, this assumes that Windows 11 is being used, as it contains the x86_64 emulator with ARM64EC support. The major difference between plain ARMv8 and ARM64EC code is that the latter has changes on an ABI level to e.g. calling conventions that ease interoperability between emulated x86_64 and ARM64 code.

Although technologically impressive, Windows 11’s marketshare is still rather small, even before looking at Windows 11 on ARM. It’ll be interesting to see whether Qualcomm’s bravado comes to fruition, and make ARM64EC more relevant for the average software developer.

Automation Makes Traditional Japanese Wood Finishing Easier

March 28, 2024 by 21 Comments

Unless you move in architectural circles, you might never have heard of Yakisugi. But as a fence builder, [Lucas] over at Cranktown City sure has, with high-end clients requesting the traditional Japanese wood-finishing method, which requires the outer surface of the wood to be lightly charred. It’s a fantastic look, but it’s a pain to do manually. So, why not automate it?

Now, before we get into a whole thing here, [Lucas] himself notes that what he’s doing isn’t strictly Yakisugi. That would require the use of cypress wood, and charring only one side, neither of which would work for his fence clients. Rather, he’s using regular dimensional lumber which is probably Douglas fir. But the look he’s going for is close enough to traditional Yakisugi that the difference is academic.

To automate the process of burning the wood and subsequently brushing off the loose char, [Lucas] designed a double-barreled propane burner and placed it inside a roughly elliptical chamber big enough to pass a 2×8 — sorry, metric fans; we have no idea how you do dimensional lumber. The board rides through the chamber on a DIY conveyor track, with flame swirling around both sides of the board for an even char. After that, a pair of counter-rotating brushes abrade off the top layer of char, revealing a beautiful, dark finish with swirls of dark grain on a lighter background.

[Lucas] doesn’t mention how much wood he’s able to process with this setup, but it seems a lot easier than the manual equivalent, and likely yields better results. Either way, the results are fantastic, and we suspect once people see his work he’ll be getting more than enough jobs to justify the investment.

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