Mysterious Files PH

As strong and light as carbon fiber-epoxy composites are, the same can’t always be said of carbon-fiber reinforced 3D printer filaments. Of those that do improve over stock filament, the best performance comes from long, continuous strands, but the printers that can embed these are quite expensive. [MagicLAG], looking for a cheaper method, made something even stronger: prints reinforced with subsurface carbon-fiber cloth.

They tried a few other methods first, including pausing the print and manually embedding carbon fiber strands, ironing strands into the finished part, and ironing carbon fiber cloth into the bottom layer. For the main method, though, he printed the test part in three pieces: a core part, and two outer shell layers. Between the core and the shell is a small gap, into which carbon-fiber cloth can be epoxied. Under good conditions (not using quick-setting epoxy), this mostly preserves the outer surface and dimensional accuracy.

To test the various strengthening methods, [MagicLAG] printed hooks and tensioned them on a load cell until failure. None of the methods using single-stranded fiber showed any improvement; the fiber simply bent and let the surrounding plastic break. As a control for the epidermal cloth parts, they printed shells and cores and epoxied them together. These controls performed better than the standard parts, but not nearly as well as the carbon-fiber cloth composites. With only a few layers of cloth, these more than tripled the yield strength of the basic hook.

If you’d rather use a carbon-fiber filament, the type of plastic matters; carbon fiber makes PLA, at least, weaker. Regardless of form, some caution is called for whenever handling carbon fiber, since it seems to show some asbestos-like effects.

If you used a serious computer pre-IBM PC, there was a fair chance its operating system was CP/M. CP/M was a staple among 8080 and Z80 computers and while there were other versions, we’ll always associate CP/M with the Z-80. There was a CP/M made for the PC which used an 8088 (a hybrid 8-bit bus with a 16-bit 8086 core), but it was overwhelmed by MSDOS. However, there was another interesting version made for the 68000, and now [johnsonjh] has ported that over to create an early version of CP/M for 80386 protected mode.

The Z-80 only had a 16-bit address bus, so it could only handle 64K of memory. It was common to “bank switch” some memory, and CP/M Plus could be made to understand that (for example, you might have 32K of common memory and three banks of 32K memory; you could address one bank at a time). However, the 386 had a full-blown memory management unit that could remap physical 4K memory pages to anywhere in a program’s virtual address space.

Ordinary CP/M couldn’t handle that, but the Motorola 68000 had a similar page management model, so it makes sense it might be easier to port CP/M-68K to the 80386 than starting from the original, even though the instruction set for the Z-80 is conceptually more similar to the 80386.

What can you do with it? We don’t know. Presumably, it will allow you to use lots of memory. Historically, CP/M software from one variant would not run on another, so you’ll have to build anything you want to use. Of course, the real killer for lots of CP/M memory was multitasking, but that takes MP/M, and only about half of that is currently working. But we won’t be surprised to see it completed soon.

While CP/M skills won’t land you many jobs these days, it is a pretty good way to get mentioned on Hackaday.

Over the years I have been to many hacker camps and done a lot of very cool things, but BornHack 2026 brought me something entirely new: Radio. By which I don’t mean radio in terms of amateur radio, LoRa, or whatever, but Radio. Broadcast radio, because the camp had a special event FM radio station for the first time. And because in a previous life I spent an inordinate amount of time in my university’s student radio station and have the Radio Voice to prove it, I was totally there for it.

For a hacker camp, one of the special things about BornHack Radio was unexpected, that it was entirely analogue. No online streams, the only broadcast was over the air, 5 watts ERP from a vertical antenna stuck on a mast at the highest point of the Hylkedam scout camp site. I don’t know whether any of the residents of the isle of Funen listened, or what they made of it, but it certainly reached as far as the two closest towns.

The other unexpected feature of the station was that it had no music licensing. Personally I viewed this as an asset, because it forced the programming to be hacker-focused rather than suit the musical tastes of whichever people are enthusiastic enough to be DJs. I sincerely hope they don’t get a music licence at future events, speech-only gives it a special quality.

The studio for an analogue station like this one can be surprisingly simple, in that it’s a mixing desk to bring all the different microphones and other inputs together and set the levels, and not a lot else. the whole thing was in a Coleman shelter on the main drag through the camp, so as studios go it could have been quieter. Programming varied from talk shows through interview shows, a live feed from the speaker tent — is this the first ever Hacker Jeopardy broadcast? — and a beautifully done robotic numbers station which I suspect may also have been part of one of the on-camp games.

I brought two shows to the airwaves, both recorded, the first of which was a BornHack take on the Hackaday Podcast format, and the second a half-hour roving interview show. I believe I may be the first person ever to live-commentate a pixelflood screen in the style of Formula One coverage.

The thing that struck me most in my first foray into radio journalism was how straightforward it was. Wander the camp with microphone (complete with fluffy windshield and 3D-printed Hackaday cube), drop the results into Audacity, and a remarkably straightforward editing process compared to video. Last time I did this it involved 1/4″ tape and a razor blade.

So that was BornHack Radio, a new experience at a hacker camp both for those of us who ventured forth on the airwaves, and I hope also for the listeners. A format in which the live shows disappeared into the aether rather than having an online afterlife gave the whole thing a freedom rarely found in 2026. I really hope this isn’t the last time I break out the fluffy microphone at a hacker camp.

Thanks to [⁨Morel Sourvalley⁩] for the images.

In the 1980s, France was the stage for one of the boldest public computing projects of the era. Minitel was the French take on viewdata, and instead of making it an expensive and unattainable luxury, they made the terminals universally available. Many Minitel services cost extra to use, but despite this it was a runaway success that lingered on into the 21st century.

The ubiquitous terminals are now surplus to requirements, but that’s not to say they are useless. [MemoireMorte] has proved this with the Memo-1, a 6502-based computer designed to plug into a Minitel-1 terminal. It’s just the accessory your Minitel needs!

Hardware wise it’s a relatively conventional device with the usual RAM, ROM, and BASIC. There’s an expansion port, and a 6522 to provide a couple of Atari joystick ports. The serial port uses a a 6551 ACIA rather than the more usual W65C51 because of an incompatibility between the latter chip and the Minitel-1.

We like this computer, not because of novelty, after all it’s hardly the first 6502 we’ve seen, but because of its use of the Minitel terminal. These devices are magnificent, and deserve more love. We subjected another terminal to a teardown a year or two ago.

Circuit bending is a chaotic art. At its simplest, it can just involve making connections between random points on a circuit board to create weird sounds in musical hardware. Or, you can complicate things, get really specific with your hookups, and twist them with various sorts of modulation. [Simon the Magpie] has been working on something closer to the latter category, with his neat project to add MIDI to the circuit bending world. 

The concept is straightforward enough. [Simon] has created a device that you place in line with your circuit bent connections, particularly those that create pitch bends with pots thanks to their variable resistance. You can then play your MIDI keyboard, and the device will vary the resistance in the circuit and bend the pitch at your command. [Simon] simply calls the device MIDI TO RESISTANCE, because that’s… precisely what it does, with the aid of a digital potentiometer. He then demonstrates it doing its thing on pitchbent toys, and it sounds pretty radical in use.

If you’re trying to make your circuit bent toys and instruments more musical, this build should serve as a great inspiration. We’ve featured other oddball musical hacks in a similarly creative vein before, too—such as using mixers as a synthesizer in their own right. Have fun out there.

[David] has a young child who is clever enough to use a computer to play music, but he doesn’t quite want to hand over the mouse just yet. Thus, he set about building an electronic music player that could be operated in an altogether simpler fashion. 

The build is based around an Arduino Nano — its job is to read RFID tags via an RC522 reader, with the tags themselves embedded in a series of small dolls belonging to [David]’s daughter. Upon reading the tag, the Arduino Nano chats over serial with a DFPlayer Mini module, which reads a playlist of MP3 files off of an SD card and plays them over a small 4 ohm speaker that [David] had laying around. It’s a simple build, with the components all neatly wrapped up in a handsome wooden case with a volume control and a skip button for if any one song becomes too annoying for a repeat listen.

We’ve featured other builds in this vein before, too. There’s something satisfying about a music player with such a simple interface—no delicate media to fiddle with, just pop the toy on top and get the playlist you were looking for. If you’re creating your own little musical builds at home, we’d love to see them on the tipsline.

Apparently you all love lasers just as much as we do. We put out a challenge to use, build, or otherwise abuse our favorite coherent light sources, and you responded. Some of the projects had been in the works for quite a while and were ridiculously polished, some were whipped together on the fly just for the contest, and we truly enjoyed both.

We only have three $150 DigiKey gift certificates to give out, though, so without further ado, we present to you…

The Winners

Our judges’ favorite project was [Jacob]’s CubeRaman, and it’s not hard to see why. A Raman spectrometer shines laser light at an object and catches the reflection, filtering all of the original laser wavelength out. What remains are photons that have interacted with electrons in the atoms that make up the target itself, and come back at a shifted wavelength. Comparing the spectrum of this Raman reflection with a database of known spectra tells you what it is made of.

This is by no means an easy project, but [Jacob]’s documentation, careful selection of parts to buy used and parts to build, coupled with a clever 3D-printed mounting system make it plausible for the home gamer. We love seeing out-of-reach science gear brought into reach, and we know we’ll be keeping an eye on this project in the future.

Next up, we had [Kyle Mayer]’s Measuring Microns with Lasers, which is a DIY laser rangefinder, but for measuring very small distances — under a centimeter — with precision. Like many laser optical rangefinders, this bounces a laser off the target and collects the light on a line sensor, using the angle at which the light returns to figure out how far the target is.

[Kyle]’s implementation uses three of these measurement heads and produces a reading that is precise down to 0.25 μm nearly 5,000 times per second. This puts it in league with devices that you have to request a quote for, so you probably don’t want to have to afford them.

And finally, an art project! [AJRussell]’s Glow Engine is a beautiful take on a familiar laser trick: shining a blue laser at glow-in-the-dark materials to leave persistent traces. Scan the laser over the phosphorescent screen, and you have something like a CRT, only in [AJ]’s case, a very very slow CRT.

The beauty here lies in the details. [AJ] chose high quality strontium aluminate for the glowing, and used high resolution encoders and the open-source SimpleFOC motor driver firmware to get the spots in the right place. Snippets of old hard drive platters make fantastic mirrors. All in all, a super implementation that we’re pretty sure looks even better in the real world.

Honorable Mentions

We always come up with a few honorable mention categories to give you all some inspiration. And it also gives us a nice excuse to feature some more sweet projects.

Lightshow

We wanted to see pretty displays of laser light. [Daniel Ross]’s Laser Oscilloscope 360 not only draws out pretty waveforms, but it does so in prime steampunk style. Both [Owen Trueblood]’s Laser Cyanotypes and [GRNCH]’s Scored: Laser Woodblock Prints flip the script, making beautiful images from lasers, but not the way we intended. Kudos.

DIY

We wanted to see what laser-involved projects you were building yourselves, from scratch. While we were shocked that we had no TEA laser entries, [Armin Bindzus]’s Versatile Laser Processing Machine more than made up for it. It’s a pulsed-laser do-everything machine that we’re absolutely jealous to see made real. And if you don’t think there’s some real laser DIY going on here, you’ve never maintained a q-switched diode pumped Nd:YAG laser.

With Remaining Eye

This was our catch-all category for doing basically anything else with lasers. It turns out that what you all mostly wanted to do was science. [Matt Venn] used a fast-rise-time laser driver to Measure the Speed of Light at Home, and got damn good results considering the 2 m baseline. [Tim] put together a 3D Printed Optical Cavity interferometer on a budget.

But it wasn’t all labcoats and pocket protectors. [WeldingRod1]’s Laser Bandsaw is basically as bad an idea as it sounds like it is. Please, please wear eye protection!

Thanks again to DigiKey for sponsoring the contest. We’re sure that our winners will find whatever they need for their next laser project.