2026-04-19 01:00:16
There are two UNIVAC 1219B computers that have survived since the 1960s and one of them is even operational. [Nathan Farlow] wanted to run a Minecraft server on it, so he did. After a lot of work, of course, which is described in a detailed blog post, and, a YouTube video by [TheScienceElf] we’ve embedded below.
The UNIVAC is a seriously weird architecture by modern standards: it’s got eighteen-bit words — yeah, not even a power of two — and one’s compliment arithmatic with a weird signed zero thing going on. There’s one 36-bit and one 18-bit register, and only 40,960 words of memory. Eighteen-bit words. Yeah, it was the 1960s and they were making it up as they went along.
[Nathan] wasn’t, entirely, as this weird system is both well-documented and already had an emulator — in BASIC, of all things. [TheScienceElf] used the docs and the existing emulator to recreate his own in Rust so he could test their somewhat crazy plan without wasting cycles on real hardware. The plan? Well, there are really only two options if you want to build modern software for a niche architecture: one is to add niche support to something like GCC, and the other is to write a RISC V emulator and compile to that. We’ve seen that second one before, and that’s the route [Nathan] took.
Of course, [Nathan] is a machine learning guy, so he made the best possible use of LLMs — though it’s interesting to see that unlike Z80 Assembly, Claude Code really couldn’t wrap its virtual head around the UNIVAC’s assembly language, and [Nathan] had to bang out the RISC V emulator himself. Emulator in hand, [Nathan] and friends had code to run on the museum UNIVAC. A single frame of an NES game took 40 minutes, but hey, at least it finished before they got back from lunch.
[TheScienceElf]’s YouTube treatment teases hosting Minecraft, but it wasn’t a full server, just the login portion. That they were able to get TCP/IP over serial and set up a handshake between a 2020s laptop and a 1960s computer is still mighty impressive. Just the work the Vintage Computer Federation put in to get and keep this antique running is mighty impressive all on its own, but it’s wonderful they let people play with it.
2026-04-18 22:00:01
There is a currently ongoing debate in the neuropsychology world about how we relate to the tools that we use. The theory of “tool embodiment” says that when we use some tools frequently enough, our brain recognizes them similarly to how it recognizes our own hands, for instance. There is evidence and counter-evidence from experiments with prosthetics, trash-grabber arms, and rubber dummy arms, just to name a few. It’s fair to say the jury is still out.
All I know is that today my trackball broke, and using a normal gaming mouse to edit the podcast was torture. It would be an exaggeration to say that I felt like I’d lost a hand, but I have so much motor memory apparently built up in my use of the trackball that switching over to another tool to undertake the exact same series of hundreds of small audio edits – mostly compensating for the audio delay across continents, but also silencing coughs and background noises – took an extra hour.
Anyone who has switched from one keyboard to another, or heck even from emacs to vim, knows what I experienced. My body just knows how to flick my wrist to make the cursor on the screen move over to the beginning of that “umm”. It’s not like I don’t conceptually know how to use a mouse either, and it does exactly the same job. But the mouse wasn’t my tool for this application. And saying that out loud makes it almost sound like I’m bordering on embodying my trackball.
I probably should have taken the trackball apart and replaced the bad tact switch on the left-click – that would have taken maybe twenty minutes – but I completely underestimated how integral the tool had become to the work. Anyway, as I write this, tomorrow is Saturday and I’ll have time to fix it. But today, I learned something pretty neat about myself in the process, even if I don’t think my single datapoint is going to rock the academic psych world.
2026-04-18 19:00:12
[Jeremy Bell] loves scratching, but he had a problem. His Hercules DJ controller wasn’t really doing a great job at emulating the kind of action one would get with a real turntable. The solution was both mechanical and electronic in nature!
As stock, the Hercules MIDI rig lets you scratch in a relatively simplistic way. When it detects a finger touching the rotary control, it lets you scratch back and forth with great motion tracking. However, when you let go, playback resumes at regular speed instantaneously, which creates a somewhat inorganic sound.
The fix was to make some mechanical mods to the MIDI controller. [Jeremy] tried out a variety of different methods of using a motor to spin the rotary control continuously, from geared rigs to belt-driven setups. It was then possible to scratch on the controller, and then let it return to normal rotational speed, creating much smoother auditory transitions. However, this was imperfect, as for whatever reason, the Hercules rig would stop tracking the rotary control accurately unless it detected a finger was touching it. [Jeremy] worked around this by whipping up a slip-ring-like setup to keep his body permanently in contact with the rotary control even while spinning.
The results are pretty great—they’re both mechanically janky and fantastically satisfying to listen to. We’ve featured some other great DJ controller hacks over the years, like this sweet Pioneer UI upgrade.
2026-04-18 16:00:02
There’s something to be said for a simple wind-up, free flight model airplane. With no controls, it must be built very well to fly well, and with only the limited power of a rubber band, it needs a good, high-lift design without much superfluous drag to maximize flight time. There’s also something to be said for modernity though, and prolific hacker [Tom Stanton] puts them together with this supercapacitor plane.
If that sounds familiar, it’s because [Tom] did this before back in 2023. But for that first attempt he converted a commercial R/C toy rather than a plane optimized for low-power free flight. Just like with the best rubber-band machines, his goal for the new production is more flight time than winding time. Plus lots of views on YouTube, but that goes without saying.
Thus this machine is smaller and lighter than the previous iteration. Rather than balsa and tissue like the free-flight aircraft of our youths, [Tom] is using 3D printed plastic for the structure. But he’s got a neat hack built in: he’s printing the wings and control surfaces directly onto tissue paper, eliminating the bonding step. Of course that means his wings are printed flat, but a bit of heat and some bending and he has a single-surface airfoil. Single-surface airfoils are normal in this application, anyway: closed wings add too much weight for too little gain. If you want to try the technique, he’s got files on Printables.
Another interesting factoid [Tom] discovered is that the energy density of supercapacitors decreases sharply below 10 F. As you might imagine by the square-cubed law, bigger is better, but the sharp drop-off dictated he use a single 10 F cap for this build, along with a micro motor. Using the wind-up generator from his previous build, he’s able to get 45 seconds of flight out of just 4 seconds of cranking, a good ratio indeed.
[Tom] seems to like playing with different ways to power his toys; aside from supercapacitors, we’ve also seen him finessing aircraft air motors — including an attempt at a turbine for a model helicopter.
2026-04-18 13:00:43
Generally when a game console with an optical drive stops reading discs the first thing that people do is crank on the potentiometer that controls the power to the laser diode to ramp up its output. While this can be a necessary solution to eke out a bit more life out of a clearly dying laser diode, this can actually massively shorten the lifespan of a good diode that’s just held back by bad capacitors. This is demonstrated by [Skawo] with a fix on a GameCube that stopped reading discs.
While it’s absolutely true that laser diodes have a limited lifespan, so do the capacitors and other components in the system. Thus, after tearing down this Japanese GameCube, [Skawo] accesses the optical PCB for some delicate plier-based capacitor surgery. One can absolutely question such violence, as well as the replacement mix of MLCC ceramics and a stray THT electrolytic capacitor, but the results after reassembly are obvious.
Without having to adjust the laser diode’s potentiometer, the game console now happily reads the game disc while the laser diode breathes a sigh of relief. Although all GameCube consoles will face the inevitable demise of their optical drives – barring a replacement optical pickup solution appearing – with this capacitor replacement solution it’s at least possible to stave off that undesirable time for a bit longer.
2026-04-18 10:00:41
Those who have worked on a hobby operating system for x86 will have interacted with its rather complex and confusing interrupt model. [Evalyn] shows us why and how to use Flexible Return and Event Delivery (FRED), a new standard by the x86 Ecosystem Advisory Group.
Of course, it would be silly to omit the fact that Linux received patches first. But that isn’t the interesting part; after all, Linux is often the first place to have support for this kind of thing. No, what’s interesting is [Evalyn]’s implementation, to our knowledge among — if not the first — non-Linux operating system to support it.
To know why we should switch to FRED, we must first understand what it replaces. The Interrupt Descriptor Table (IDT) tells the CPU what code to run when certain interrupts or faults happen. The big problem that the IDT has is inconsistency, most egregiously the fact that the stack layout depends on which interrupt happened. To solve the issues with the IDT, FRED was created.
[Evalyn] shows us the process, starting at the documentation, then finding an emulator capable of it and culminating in a demo where DOOM runs in EvalynOS with FRED enabled.
Pentium II die shot. Martijn Boer, Public domain.
