3D Printing A Telescope Is Rewarding, Even If Not Always Cheaper

December 29, 2025 by 1 Comment

What can one expect from 3D printing an 8″ Newtonian telescope? [Molly Wakeling] shares her thoughts after doing exactly that. The performance was on par with any solid 8″ telescope, but in the end it wasn’t really any cheaper than purchasing a manufactured unit. Does that mean it wasn’t worth it? Not at all!

[Molly] makes the excellent observation that the process of printing and building one’s own telescope is highly educational and rewarding. Also, the end result is modular, user-serviceable, and customizable in a way that many commercial offerings can only dream of. It’s a great conversation starter with other enthusiasts, as well!

[Molly] printed the 203 Leavitt design (3d models available on Printables) which is an 8″ Newtonian telescope. This telescope design uses a concave parabolic mirror (a significant part of the expense) at the back of the tube to gather and focus light, and a small flat mirror near the front of the tube reflects this light to an eyepiece on the side. The wood stand makes things convenient, and we like the elastic tie-down used as a simple way to put tension on the mounts.

Do you find yourself intrigued but would prefer to start a little smaller and cheaper? Good news, because the same designer of the 203 Leavitt has a very similar design we happen to have featured before: the 114 Hadley. It features easily obtainable, lower-cost optics which perform well and can be easily ordered online, making it a great DIY starter telescope.

39C3: Recreating Sandstorm

December 29, 2025 by 1 Comment

Some synthesizer sounds are just catchy, but some of them are genre-defining. We think you could make that case for the Roland JP-8000 patch “Sandstorm”, which you’ve heard if you listened to any trance from the 90’s, but especially the song that was named after it.

“Sandstorm” is powered by the Roland Supersaw, and synth nerds have argued for a decade about how it’s made. The JP-8000 is a digital synthesizer, though, so it’s just code, run through custom DSP chips. If you could reverse engineer these chips, make a virtual machine, and send them the right program, you could get the sound 100% right. Think MAME but for synthesizers.

That brings us to [giulioz]’s talk at the 39th Chaos Communication Congress, where he dives deep into the custom DSP chip at the heart of the JP-8000. He and his crew had approached older digital synths by decapping and mapping out the logic, as you often do in video game emulation. Here, getting the connections right turned out to be simply too daunting, so he found a simpler device that had a test mode that, combined with knowledge of the chip architecture, helped him to figure out the undocumented DSP chip’s instruction set.

After essentially recreating the datasheet from first principles for a custom chip, [guiloz] and team could finally answer the burning question: “how does the Supersaw work”?  The horrifying answer, after all this effort, is that it’s exactly what you’d expect — seven sawtooth waves, slightly detuned, and layered over each other. Just what it sounds like.

The real end result is an emulation that’s every bit (tee-hee!) as good as the original, because it’s been checked out on a logic analyzer. But the real fun is the voyage. Go give the talk a watch.

Different Algorithms Sort Christmas Lights

December 29, 2025 by 6 Comments

Sorting algorithms are a common exercise for new programmers, and for good reason: they introduce many programming fundamentals at once, including loops and conditionals, arrays and lists, comparisons, algorithmic complexity, and the tradeoff between correctness and performance. As a fun Christmas project, [Scripsi] set out to implement twelve different sorting algorithms over twelve days, using Christmas lights as the sorting medium.

The lights in use here are strings of WS2812 addressable LED strips, with the program set up to assign random hue values to each of the lights in the string. From there, an RP2040-based platform will step through the array of lights and implement the day’s sorting algorithm of choice. When operating on an element in the array the saturation is turned all the way up, helping to show exactly what it’s doing at any specific time. When the sorting algorithm has finished, the microcontroller randomizes the lights and starts the process all over again.

For each of the twelve days of Christmas [Scripsi] has chosen one of twelve of their favorite sorting algorithms. While there are a few oddballs like Bogosort which is a guess-and-check algorithm that might never sort the lights correctly before the next Christmas (although if you want to try to speed this up you can always try an FPGA), there are also a few favorites and some more esoteric ones as well. It’s a great way to get some visualization of how sorting algorithms work, learn a bit about programming fundamentals, and get in the holiday spirit as well.

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Keyboard-Mouse, Again

December 29, 2025 by 3 Comments

The astute among you may remember an earlier version of this Russian beauty, the Lapa, which I featured last year around this time. Creator [lemosbor] claims that the worry was less about visual beauty and more about ergonomics. Way more. Well then, let this serve rather nicely as a textbook definition of that old form-follows-function principle.

A splendidly ergonomic split with few keys, large openings under the palms and wrists, and mouse control on the thumbs.
The lovely Lapa.

See, [lemosbor] believes that the keyboard must adapt to the hands and not the other way around. The main goals were to minimize hand and finger movement as well as the visual attention required of the keyboard itself. No, there were never going to be any screens or RGB, and there likely never will be.

But I refuse to sidestep the obvious beauty in this keyboard, which from the side resembles a stylish and expensive pair of slightly-heeled shoes that were tailored to the contours of the human hand. And let’s not forget those handmade, oval keycaps, which again are a product of form-follows-function.

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39C3: Hacking Washing Machines

December 29, 2025 by 4 Comments

Many of us have them, few of us really hack on them: well, here we’re talking about large home appliances. [Severin von Wnuck-Lipinski] and [Hajo Noerenberg] were both working on washing machines, found each other, and formed a glorious cooperation that ended in the unholy union of German super-brands Miele and B/S/H — a Miele washer remote controlled by Siemens’ web app.

This talk, given at the 39th Chaos Communication Congress (39C3), is about much more than the stunt hack, however. In fact, we covered [Severin]’s work on the very clever, but proprietary, Miele Diagnostic Interface a little while ago. But now, he’s got it fully integrated into his home automation system. It’s a great hack, and you can implement it without even opening the box.

About halfway through the talk, [Hajo] takes over, dissecting the internal D-Bus communication protocol. Here, you have to open up the box, but then you get easy access to everything about the internal state of the machine. And D-Bus seems to be used in a wide range of B/S/H/ home appliances, so this overview should give you footing for your own experimentation on coffee machines or dishwashers as well. Of course, he wires up an ESP32 to the bus, and connects everything, at the lowest level, to his home automation system, but he also went the extra mile and wrote up a software stack to support it.

It’s a great talk, with equal parts humor and heroic hacking. If you’re thinking about expanding out your own home automation setup, or are even just curious about what goes on inside those machines these days, you should absolutely give it a watch.

Editor Note: The “S” is Siemens, which is Hackaday’s parent company’s parent company. Needless to say, they had nothing to do with this work or our reporting on it.

How Wind Nearly Took Down Boulder NTP

December 29, 2025 by 11 Comments

NTP is one of the most interesting and important, but all too forgotten, protocols that makes the internet tick. Accurate clock synchronization is required for everything ranging from cryptography to business and science. NTP is closely tied around a handful of atomic clocks, some in orbit on GPS satellites, and some in laboratories. So the near-failure of one such atomic clock sparked a rather large, and nerdy, internet debate.

On December 17, 2025, the Colorado front range experience a massive wind storm. The National Center for Atmospheric Reassure in Boulder recorded gusts in excess of 100 mph (about 85 knots or 160 kph). This storm was a real doozy, but gusts this strong are not unheard of in Boulder either. That is no small reason the National Renewable Energy Laboratory (now the National Laboratory of the Rockies) has a wind turbine testing facility in the neighborhood.

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Only Known Copy Of UNIX V4 Recovered From Tape

December 29, 2025 by 29 Comments

UNIX version 4 is quite special on account of being the first UNIX to be written in C instead of PDP-11 ASM, but it was also considered to have been lost to the ravages of time. Joyfully, we can report that the more than fifty year old magnetic tape that was recently discovered in a University of Utah storeroom did in fact contain the UNIX v4 source code. As reported by Tom’s Hardware, [Al Kossow] of Bitsavers did the recovery by passing the raw flux data from the tape read head through the ReadTape program to reconstruct the stored data.

Since the tape was so old there was no telling how much of the data would still be intact, but fortunately it turned out that the tape was not only largely empty, but the data that was on it was in good nick. You can find the recovered files here, along with a README, with Archive.org hosting the multi-GB raw tape data. The recovered data includes the tape file in SimH format and the filesystem

Suffice it to say that you will not run UNIX v4 on anything other than a PDP-11 system or emulated equivalent, but if you want to run its modern successors in the form of BSD Unix, you can always give FreeBSD a shot.