Mysterious Files PH

Although cryocoolers are capable of pretty impressive cooling, for many of them the underlying working principle is simple enough that you do not need any special skills or a big budget to make your own version. Take the Gifford-McMahon cryocooler for example, which works using nothing more than some kind of coolant gas and a piston in a cylinder that you can even 3D print, as demonstrated by [Hyperspace Pirate] in a recent video.

The lowest temperature reached across the two prototypes was only -84°C, but this was mostly due to some sub-optimal design choices, such as the use of regular air and a clear acrylic tube to get a good glimpse at the inner workings. The trickiest part of this type of cryocooler is probably that you need to move the piston containing the regenerator between both ends of the cylinder to get a cool and a hot side.

That particular problem was solved by using magnets to move the piston externally, which worked beautifully until the problem of using regular compressed air from the shop compressor caused massive ice formation that jammed up the piston. Obviously this was not an unexpected issue, and for the next step the coolant gas will be replaced by helium, as making that gas freeze up requires quite a bit more effort.

A good demo, like [Linus Akesson]’s Sum Ergo Demonstrato, looks like magic to the average hacker. To normies who don’t know the limitations of the RP2350, they don’t see the big deal. To anyone who has spent any time with the chip, though, it’s a series of tricks you cannot help but be amazed by. Fortuanately for us, [Linus] isn’t actually a magician, because while a magician never reveals his tricks, [Linus] has an hour-long video explaining exactly how his demo was accomplished. We’ve embedded both the demo and the explanation below.

Even if you aren’t into YouTube, you should check out the demo video, and again– remember this is all on a Pi Pico with only the extra passives required for video-out. Then you can watch [Linus] explain how he did it, which is really best heard in his own words. There are a couple of bleeding-edge tricks on the RISC V core and peripherals that we would hate to misrepresent– especially the clever hack with the interpolator that he uses for 3D acceleration.

If this sounds a bit familiar, it’s because we were equally impressed by his Kaleidoscopico demo last year. From demos like this to 3D engines on the ESP32, its amazing what you can do on modern micros if you’re willing to hit the limits of the hardware.

Thanks to [Stephen Walters] for the tip!

The Demo:

Technical video:

If you’ve ever worked with I2C, you know its one of those things that makes working with modern microcontrollers such a pleasure. With a few wires and not many more lines of code, you can communicate with all sorts of hardware such as sensors, displays, and input devices. There are even I2C keyboards out there, although they tend to be a bit pokey — and not in the good way as it pertains to keyboards.

But the bt2i2c project from [Roberto Alsina] promises to improve things. With his firmware flashed to a Pi Pico W, you can establish a connection with any standard Bluetooth keyboard and have the keystrokes sent over the wire via I2C. As far as your project is concerned, the input will appear to be coming from a BlackBerry BBQ20/BBQ10 keyboard using the address 0x1F, which means that there’s already plenty of code out there to work with. While [Roberto] explains its not strictly necessary, connecting a ST7789 display to the Pi Pico over SPI will give you some visual feedback on connection status.

As microcontrollers become increasingly powerful and capable of the sort of thing we would once have done on a “real” computer, a project like this has some fascinating potential. We’ve seen a number of “writerdeck” projects running on chips like the ESP32, and it’s not hard to see the appeal of being able to easily pair your favorite Bluetooth keyboard up to one of them.

Professional Stratasys FDM printers demand a pretty hefty price premium over your typical hobbyist-level machine, with the gold-plating continuing even with the special filament cartridges that you buy for some of their printers.

This raises the question of in how far this eye-watering price tag is justified, and how much is just you paying for support and the brand name. After acquiring a spool of Stratasys ABS filament via a US viewer, [Dr. Igor Gaspar] set to work to try and answer this question.

The viewer had already liberated the spool of ABS+ P430 filament from its cartridge, making it easy to use that directly with the Bambu Lab FDM printer.

To make it a fair comparison, [Igor] also needed to have a sample printed on a real Stratasys printer, for which he used a local company’s services. An interesting sidenote here is that the US viewer’s company moved away from Stratasys to Bambu Lab printers.

[Igor] was able to see his test parts being printed on the Stratasys printer, as said company is in the same city. This showed him that it took 14 hours to print the parts versus 3.5 hours on the Bambu Lab printer, suggesting that his worries about the right printing parameters for the Stratasys filament were warranted. Sussing those out was thus paramount for a fair comparison and warranted some test prints.

From a sheer aesthetic point of view the Stratasys-printed parts looked much cleaner, and their dimensional accuracy was also significantly better due to the slicer adjusting for this. Between the used Stratasys M30 and Bambu Lab ABS filaments there’s no clear winner, with both trading blows. Amusingly enough, the older Stratasys ABS type in the form of the ABS+ P430 filament performed the best of all when printed on the Bambu Lab printer at its preferred temperature setting.

Moral of the story is thus that – unless you really want to pay for that service contract – to loot old Stratasys ABS spool cartridges and use them in your hobbyist FDM printer. As [Igor] says in the conclusion, the nicer looks is probably due to them printing very thin layers, much finer than the 0.2 mm layers he used. This would also match the much longer print time and is thus something we can replicate on any FDM printer with a temperature-controlled printing environment.

It’s become an accepted truth amongst tapeheads that there’s no point looking at new hardware, because there’s only one tape mechanism being made anywhere in the world anymore, and that it sucks. [VWestlife] may enjoy German automobiles, based on the name, but he’s also a tapehead– and he took the time to demonstrate on YouTube that the accepted truth just ain’t so.

The supposed One Mechanism to Rule Them All in Lo-Fi is designed or made by Chinese company Tanishin. Certainly Tanishin does make a tape mechanism, but as [VWestlife] demonstrates with a few teardowns, there’s absolutely more than one on the market. That doesn’t mean any of the new offerings will out-compete your vintage Sony Walkman, but it does mean there are differences worth considering if you were to buy new.

Note that it is handhelds like the Walkman being talked about– it must be, since there are both slot-loading and flip-loading decks still being made, and even if you’re not a tapehead you should be able to tell that those won’t share the same part on the BOM.

With a few teardowns, he finds three separate mechanisms, followed by a deep-dive into the Tanishin. If you’re looking to buy a new walkman– or perhaps use its guts to build a mass storage device-– you might want to watch the whole thing to help you pick. On the other hand, the mechanism doesn’t matter that much, as he points out. It brings the tape over the head, but that’s not difficult. Everything else– from the motor that needs to draw the tape out evenly, to the pickup and the preamps and amplifiers–is where noise and poor quality sound tends to creep in, especially when something’s built to a budget.

Overall, [VWestlife] takes pains to point out that these ‘crappy’ new players aren’t any worse than the original Sony Walkman– we’ve just been spoiled by decades of better media than the humble compact cassette. That’s no slight against the cassette– people are still pushing its limits to this day, like this insanely fast vacuum-driven mechanism we featured.

Thanks to [Stephen Walters] for the tip!

Although the thought of installing a modern operating system like Windows 11 on something as archaic as a Core 2 Quad Q6600 Intel CPU may seem ridiculous, it being the flagship CPU of the time means that it still chews up low-end Celeron systems that are on the supported hardware list like the N4020. Hence [Omores] commencing on this latest adventure, with the snag being that the chosen mainboard features an AGP bus that Windows 11 no longer supports.

This system is intended to multi-boot a range of Windows OSes starting with Windows 98, while also playing nice with DOS and even Windows 11. In addition to the quad-core, 2.4 GHz Q6600 there’s also an amazing 3 GB of DDR1 RAM in the system.

The mainboard is the 2003-era Asrock 865PE, with the GPU being the highest-end GPU that still came in AGP flavor: the Radeon HD 4650 from 2009. Since the sole reason that Windows 11 doesn’t support AGP any more is due to the supporting files not being included with Windows 11, hence you can track it down on a Windows 10 1507 release install – such as the Intel AGP440.sys driver here – and install them with some file editing.

Since Windows 11 still supports the WDDM driver model from Windows Vista and 7 you can then install the Catalyst drivers from 2012 and be up and running. You only get 1 GB of VRAM for this card, but you probably don’t need much more on this level of hardware.

One major stumbling block remains, however, as Windows 11 24H2 enforces SSE4.2 instructions which the CPU doesn’t support. Ergo 23H2 is the newest Windows 11 version that can run on this system, with only the Education and Enterprise still receiving security updates, making it a bit of a pyrrhic victory, especially as Windows 7 benchmarks a fair bit faster on the same hardware.

This week, we’re shaking things up a little, with Tom Nardi still in the host seat, and someone besides Al Williams in the other, namely Kristina Panos.

In Hackaday news, we have a new Frikkin’ Lasers Challenge going on now, although we acknowledge that no one can actually enter their project into it at the moment. We hope to have that fixed in short order. Procrastinators, disregard.

You’ll have to wait another week for the triumphant return of What’s That Sound, but we do have an audio mailbag for you this week. Thanks, Dillon!

We look at loading SEGA games from a vinyl record, discuss a really cool project that puts live plane data on your ceiling, and debate the name ‘PopTuber’. We also discuss DIY routers, and stress over the future of electronic shelf labels.

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 in DRM-free MP3 and share it with your favorite PopTuber.

Episode 372 Show Notes:

News:

• The Frikkin Lasers Contest Starts Now

Mailbag:

• Dillon asks the crew whether they take notes while working on projects, and how. And how!

Interesting Hacks of the Week:

• Texas Instruments Changes The NE5532 And Others Into Incompatible Versions
• Loading Sega Genesis Games Off A Vinyl Record
  • VCF East 2018: The Mail Order App Store
• Make Your Ceiling Disappear With ADS-B And Short-Throw Projector
• Like A Wire Bender, But For Pop Tubes
  • GETULA
• An RGB Keyboard For Your Hackaday Communicator Badge
  • Announcing The 2025 Hackaday Superconference Communicator Badge
• DIY Ceramic Circuit Boards Surely Count As Solarpunk

Quick Hacks:

• Tom’s Picks:
  • Ways To Embed Magnets In 3D Prints And Not Ruin Printers
  • Fixing A Nintendo Game Boy Clone That Runs Too Fast
  • Ebike Display Uses Reflective LCD
• Kristina’s Picks:
  • A Camera Viewfinder Makes A Great TV
  • The Uncooperative Mirror Will Not Help You
  • A Diffraction Grating Makes This Clock Readable

Can’t-Miss Articles:

• Revisiting Making Your Own Internet Router In 2026
• Ask Hackaday: How Do You Feel About Electronic Shelf Labels?