Polystyrene Foam Can Be Gasoline With Some Help

August 4, 2026 by 2 Comments

Styrofoam – or closed-cell extruded polystyrene (XPS) foam if you want to be precise – is one of those materials that is both super versatile for packaging and insulation, but also a menace when it comes to disposal, even if you ignore that the monomer styrene (C8H8) is a known mutagenic toxin. One of the more creative ways to deal with the metric tons of polystyrene waste generated each year is to turn it into gasoline, as demonstrated by [Lowered Expectations] in a recent video.

With polystyrene being just another hydrocarbon polymer, the idea of turning these polymers into the mixture of hydrocarbon chains we call ‘gasoline’ isn’t so crazy. The problem is mostly doing it in a way that makes some economic sense and doesn’t risk turning your domicile into a hazmat risk site or threaten the health of you, your loved ones and the neighborhood.

The method demonstrated in the video uses fairly basic methods involving pyrolysis and distillation. The first step involves dissolving the polystyrene in gasoline that was previously recovered from stale gasoline, which is another dangerously fun science experiment. This creates a thick slurry that’s then put into the distillation flask for the heating phase.

After testing the distillates for spark ignition the useful distillates were combined with fuel stabilizer added. Before tossing this into a gasoline engine tank for further testing, the concerns of auto-polymerization of styrene monomers are addressed, which requires special inhibiters.

Although this mixture runs a gasoline generator just fine, a borescope inspection of the cylinders showed a build-up of a shiny, gummy residue. There’s also the issue that this mixture contains styrene monomers, which are as noted very unhealthy to breathe in from either the fuel or any remaining monomers in the exhaust. Definitely not something to try at home, basically.

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Tearing Down Aircraft Weather Radar Avionics

August 4, 2026 by No comments

If you’re flying high in the sky, it’s useful to know if there’s turbulence, heavy rain, or other nasty weather ahead. Onboard weather radar is a useful tool that pilots use to scope out conditions ahead. [Thomas Scherrer] came into possession of a weather radar display from a vintage aircraft, and decided to tear it apart for our viewing pleasure. 

The unit in question is a Bendix PPI-1 plan position indicator. This particular 1971 example was scored from a McDonnell-Douglas DC9. [Thomas] only has the display itself, not the radar that would feed it or the power supply to turn it on. Still, even just the readout unit is super interesting to look inside. Right off the bat, there’s a neat dimming filter on the front, and the case itself is really beautifully designed for service. The design is very much of its time, full of neat wire harnesses and chunky through-hole components.  There are some neat surprises inside, too, like an interesting device shaped like a triangular prism whose purpose we won’t spoil here.

If you’re wondering what one of these units looks like in action, you can see such an example on YouTube. The display basically lights up in areas where there were stronger radar returns indicating weather to be avoided.

We love radars around these parts, and we feature them all the time. Video after the break.

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A man's hands are shown holding a broken 3D-printed hook. The hook has a loop and hook, in a number 9-shape. The hook portion has broken, exposing carbon fibers.

Strengthening 3D Prints With A Carbon-Fiber Epidermis

August 4, 2026 by 4 Comments

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.

At Last! CP/M For Protected Mode

August 4, 2026 by 26 Comments

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.

BornHack Radio 102.8 FM, Playing Radio At A Hacker Camp

August 4, 2026 by 6 Comments

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.

A view of a tent shelter in bright sunlight with studio equipment visible on a table in it. There's a sign: "BornHack FM".
The BornHack Radio nerve centre.

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.

Un Ordinateur Pour Le Minitel-1 (A Computer For The Minitel-1)

August 4, 2026 by 3 Comments

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.

Road Trains Roam The Backroads Of Australia

August 4, 2026 by 16 Comments

Trains and the railways they run on are a great way to move lots of stuff, or lots of people, a long way. Steel wheels on steel rail can shift great loads at good speeds and railways remain a backbone of logistics for this very reason. The only problem is that they require a great deal of initial investment to build and plenty of maintenance to keep them functional over time.

These concerns can make a railway a difficult proposition when it comes to getting large amounts of goods in and out of remote areas. It’s a problem that Australia faces, with settlements far off the beaten track that are nevertheless in need of high-throughput freight connections. And if you can’t go rail, you go road… in a big way.

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