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Showing posts from April, 2026

AT&T’s Unix PC — We Hardly Knew You

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Before Linux, there was Unix. It was great, but it was and has been plagued by problems with licensing and proprietary competition. [Vintage Appartus] recalls, for example, the AT&T Unix PC from the 1980s. It was awesome, but you’ve probably never heard of it. For 1985, it was a nice setup. You got a 10 MHz Motorola 68010, 512K of RAM (but upgradable to 4M), a floppy, a modem, a 720×384 monochrome screen, and a 10 or 20 MB hard drive. You can check out the video explaining the machine and its problems below. Physically, the computer looked like a high-end Apple ][ with a removable keyboard and a built-in monitor. Expansion was via three slots. Cold start took about three minutes, and then you have a fairly normal Unix setup for the period. The sample machine uses a disk emulator, so the video shows the computer running much faster than it would with a real period hard drive. The card also has an 8086 expansion board that can boot MSDOS, an important feature in 1985. ...

Electronics Near Zero

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Normally, when you design an electronic gadget, you worry about how hot it will get. Automotive-grade components, for example, often have higher allowable temperatures than commercial parts. However, extremely cold environments, such as deep space or the interiors of quantum computers, are also challenging. Researchers at King Abdullah University of Science and Technology believe gallium oxide may be key to operating near absolute zero. According to [Vishal Khandelwal], one of the researchers, most conventional electronics fail below -173C or 100K. Quantum computers routinely operate at 4K. However, β-Ga 2 O 3 is a wide-bandgap semiconductor that has low current leakage and works at high temperatures up to 500C. However, it also avoids the freeze-out effect that traps electrons in other semiconductor materials. The team built two devices from the material seeded with a silicon dopant. The first was a FET with a fin-shaped geometry. The second was an inverter. Both operated reliabl...

USB-C Charger Juices Up 100 Devices At Once

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Back when phones used to ship with chargers in the box, you’d get a plugpack that could charge one device. Aftermarket manufacturers eventually started making chargers with four or five ports which were great for travelling. But what if you wanted to charge even more devices? You might build something like this rig from [DENKI OTAKU]. The goal was to build a charger that could handle 100 devices at once. The charger is designed to charge devices at up to 1.5 amps. That’s no mean feat, as the device would have to be able to deliver 150 amps total when fully loaded. As for the actual design, though, it’s relatively simple. [DENKI OTAKU] simply built a simple USB-C charger PCB based around an off-the-shelf chip which has ten individual chargers on it, and stacked it up ten of those in a housing made out of aluminium extrusion. To deliver the current to run all these chargers, the rig got two massive switching power supplies to feed the charger array a massive amount of c...

Five Different Styles of Cardboard Hinges

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Simple paper hinge. (Credit: Itoshige Studio, YouTube) One doesn’t generally associate cardboard with structural components like hinges, but [Itoshige Studio] assures us that you can absolutely create hinges out of this ubiquitous material . In total the video covers five different designs, ranging from the simple and straightforward to an interlocking tab design that approximates a typical steel hinge with paper rod to keep both sides of the hinge together. The most simple hinge is unsurprisingly just a strip of craft paper, which is also demonstrated as the hinge for a wooden box in lieu of the typical metal hinge. This same principle is then demonstrated for a fancy cardboard box. From here the hinge designs increasingly get more involved, with first a seamless hinge variation, and then a kamichoban hinge design that’s inspired by traditional Japanese room dividers and furniture, using panels that are interconnected with overlapping sections to create a fascinatingly f...

Making the Osmo Pocket 4 a More Serious Camera

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The Osmo Pocket 4 is a handheld gimballed camera that’s perfect for shooting running content on the go. However, it’s got a weird sort of form factor and is limited when it comes to things like fitting filters or recording quality sound. To that end, [Byron Seven] whipped up an upgrade kit that turns the Pocket 4 into more of a “real” camera. The idea is simple enough—the Osmo Pocket 4 is packaged in a 3D printed shell that expands its capabilities. It’s tucked into the structure with a USB power bank that greatly increases how long you can shoot before the batteries run out. In front of the gimbal head, there’s a fitting that allows attaching standard camera filters for visual effect. Topside there’s a handle for better physical control of the camera, along with a rail mount for a DJI wireless mic and a phone to act as a monitor. Down below, there’s a quick-connect fitting so the camera can be slammed on and off a tripod with ease. What’s great is that you can slot a Pocket 4 into t...

Why Model Collapse in LLMs is Inevitable With Self-Learning

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There is a persistent belief in the ‘AI’ community that large language models (LLMs) have the ability to learn and self-improve by tweaking the weights in their vector space. Although there’s scant evidence that tweaking a probability vector space is anything like the learning process in biological brains, we nevertheless get sold the idea that artificial general intelligence (AGI) is just around the corner if we do just enough tweaking. Instead of emerging super intelligence, the most likely outcome is what is called model collapse, with a recent paper by [Hector Zenil] going over the details on why self-training/learning in LLMs and similar systems is a fool’s errand. For those who just want the brief summary with all the memes, [Metin] wrote a blog post covering the basics . In the end an LLM as well as a diffusion model (DM) is a statistical model of input data using which a statistically likely output can be generated (inferred) based on an input query. It follows intuitively ...

How to Kill Humidity Sensors With Humidity

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An often overlooked section in the datasheets for popular humidity sensors like the BME280 and DHT22 is the ‘non-condensing humidity’ bit, which puts an important constraint on which environments you can use this sensor in. This was the painful lesson that [Mellow Labs] recently had to learn when multiple of such sensors had kicked the bucket after being used in a nicely steamed-up bathroom. Fortunately, it introduced him to sensors that are rated for use in condensing humidity environments, such as the SHT40 that’s demonstrated in the video. This particular sensor is made by Sensirion, and as we can see in the datasheet it features a built-in heater that allows it to keep working even in a condensing environment. This heater has three heating levels which are controlled via the I2C interface, though duration is limited to one second in order to prevent overheating the sensor. Of note is that you cannot take measurements while the heater is operating, and its use obviously increa...

Using a VT-100 Today

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You may not know what a ADM-3, a TV910, or a H1420 are, but you probably have at least heard of a VT-100. They are all terminals from around the same time, but the DEC VT-100 is the terminal that practically everything today at least somewhat emulates. Even though a real VT-100 is rare, since it defined what have become ANSI escape sequences, most computers you’ve used in the last few decades speak some variation of the VT-100’s language. [Nikhil] wanted to see if you could use a VT-100 for real work today . While the VT-100 wasn’t a general-purpose computer, it did have an 8080 inside. It only had about 3K of RAM, which was enough to act as a serial terminal. A USB serial port and a terminal with modern Linux, how hard could it be? As it turns out there were a few issues. MacOS assumes terminals can take data at 9600 baud with no handshaking, apparently. It also means that any application that assumes redrawing the whole terminal is fast will be sorry for that choice. Of course, ...

FLOSS Weekly Episode 869: Linux on Your Toaster

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This week Jonathan chats with Andrei, Mahir, and Praneeth, live on location at Texas Instruments! The team at TI has been working hard to provide really good Open Source support for Sitara processors, including upstreaming support to the mainline Linux kernel. We talk about the CI pipeline for these devices, the challenges of doing Open Source at a big company, and more. Check it out! https://github.com/texasinstruments https://www.beagleboard.org/ https://www.ti.com/design-development/software-design/open-source.html Did you know you can watch the live recording of the show right on our YouTube Channel ? Have someone you’d like us to interview? Let us know, or have the guest contact us! Take a look at the schedule here . Direct Download in DRM-free MP3. If you’d rather read along, here’s the transcript for this week’s episode . Places to follow the FLOSS Weekly Podcast: Spotify RSS Theme music: “Newer Wave” Kevin MacLeod (incompetech.com) Licensed under Creat...

Recycling PLA and Other Plastic Waste with Compression Molding

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After previously trying out low-tech compression molding with a toaster oven and 3D printed molds, [future things] is back with a video that seeks to explore some of the questions raised after the first video . Questions such as how well this method works with HDPE and PLA thermoplastics, whether the flashing could be cut off by the mold and the right temperatures and times to heat the plastic before a charge is ready for inserting into the mold. In this video the same PHA-based mold is used, but in a three-piece configuration to allow for a more complex shape. This way game tokens could be made for use by the son of the author, which also shows one straightforward and very practical use of this method. A big change here is that no more metal chopsticks are used to handle the charge, as this was found to cool down the heated plastic too much. Instead the hot charge is handled with fingers and wooden chopsticks, with the plastic heated until it has about the consistency of thick hon...

Can you 3D Print a Pinball Machine That’s Fun to Play?

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It seems fair to say that pinball machines are among the most universally loved gaming systems known today, yet the full-sized ones are both very expensive and very large, while even the good quality table-sized ones tend to be on the expensive side. That raises the question of whether a fully 3D printed pinball machine could at all be fun and not just feel like a cheapo toy? A recent video by [Steven] from [3D Printer Academy] on YouTube makes here a compelling argument that it might actually be worth something to consider. In addition to being fully modular and customizable the most compelling element is probably that the design supports two- and four-player multiplayer. This sees the metal balls leaving at the rear and from there entering the playing field of another player’s machine, which can probably get pretty chaotic. Unfortunately this is part of a Kickstarter campaign , so you’ll have to either shell out some cash to get access to the print files or DIY your own version. ...

Payphone Tag Is Australia’s New National Sport

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Australia’s payphones are an iconic part of the national landscape, even if they’re not as important as they once used to be. However, they’re having a resurgence of late, in part thanks to a new national pastime— the sport of Payphone Tag! Created by [Alex Allchin], the game is simple. To play, you first sign up on the website and get your emoji and 5-digit PIN. You then go out and find a payphone, dial the Payphone Tag number, and enter your PIN when prompted. This lets you “capture” the phone, raising your score in the game. If a phone is already captured, no matter—just head out there, dial the number, and key in your own PIN to steal it. You can also push your score even higher by capturing three payphones in a triangle on the map to get bonus points. It’s a fun geospatial game that’s also free to play, because Telstra made payphone calls free back in 2022 . It might cost you a bit to get out to some phones, but there are plenty you can reach with the aid of free public transpo...

2026 Green Powered Challenge: Supercapacitor Enables High-Power IoT

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With all the battery technologies and modern low-current sleep modes in most microcontrollers, running a sensor and microcontroller combo off-grid and far away from any infrastructure is usually not too difficult a task. Often these sorts of systems can go years without maintenance or interaction. But for something that still has to be off-grid but needs to do some amount of work every now and then like actuating a solenoid or quickly turning a servo, these battery-based systems can quickly run out of juice. To solve that problem, [Nelectra] has come up with this high-power capacitor-based IoT system . Although supercapacitors don’t tend to have the energy density of batteries, they’re perfectly capable of powering short tasks in off-grid situations like this. They’re also typically able to tolerate lower voltages, extreme temperatures, and shock better than most batteries as well. A small solar cell on the top of this device keeps it topped up, and when running in deep sleep mode ca...

Why Solid State Batteries Short

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Solid state batteries, we are told, are the new hot battery technology that will replace lithium-ion batteries. Soon. Not that we haven’t heard that before. One reason it isn’t dominating the market today is that it’s prone to short circuits during charging. [Dr. Yuwei Zhang and others have published a paper detailing why the shorts happen, which could lead to strategies to improve the technology. Solid state batteries employ a solid electrolyte and a lithium anode. It is known that, sometimes, lithium metal from the anode forms dendrites that penetrate the ceramic electrolyte and cause it to crack. This is somewhat of a mystery as the lithium is a soft metal (to quote [Zhang], “like a gummy bear.”). There were two leading hypotheses for the observations. [Zhang’s] team showed that hydrostatic stress made the lithium dendrites act like a water jet, enabling them to penetrate the hard ceramic. There is still work to figure out what to do about it, but understanding the root cause i...

A Different Kind of Ultrasonic Levitation

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Ultrasonic levitation is by now a familiar trick: one or more ultrasonic transducers create a standing wave, and small objects can be held in the nodes of this standing wave. With a sufficiently large array of transducers, it’s even possible to control the movement of the object. This isn’t the only form of ultrasonic levitation, however, as [Steve Mould] demonstrated with his ultrasonic air hockey table . This less familiar form of levitation was discovered by [Bob Collins] while working on torpedo guidance systems: when he tried to place a glass lens on an ultrasonic transducer it immediately slid off. He found during further experimentation that an ultrasonic transducer would levitate over any sufficiently flat and smooth surface. It works by trapping a very thin layer of air between the transducer and the smooth surface. When the transducer moves sharply toward the surface, it compresses a layer of air in between, and forces some air out, and the reverse happens while pulling bac...

The Challenges of 3D Printing Reliable Springs

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Springs are great, but making them out of plastic tends to come with some downsides, for fairly obvious reasons. Creating a compliant mechanism that can be 3D printed and yet which doesn’t permanently deform or wear out after a few uses is therefore a bit of a struggle. The complaint toggle mechanism that [neotoy] designed is said to have addressed those issues , with the model available on Printables for anyone to give a shake. The model in question is a toggle, which is the commonly seen plastic or metal device that clamps down on e.g. rope or cord and requires you to push on it to have it release said clamping force. Normally these use a metal spring inside, but this version is fully 3D printable and thus forms a practical way to test this particular compliant mechanism with a variety of materials. The internal spring is a printed spiral spring, with the example in the video printed in PETG. You can of course also print it in other materials for different durability and springin...

2026 Green Powered Challenge: Adding Low-Power Sleep To Microcontrollers

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When building a project to operate on battery power for long periods of time, having a microcontroller with a reliable and extremely low-power sleep mode is critical. When processing power isn’t needed, it should be able to wait around using almost no energy until an interrupt triggers it. Once triggered, the CPU performs its tasks and then puts itself right back to sleep, making sure the battery lasts as long as possible. Unfortunately, not every microcontroller has sleep capabilities or has an acceptably low level of power use for maximizing battery life. For these systems, a tool like this power manager might come in handy . The small PCB, called the powerTimer, essentially acts as a middleman for power delivery to another microcontroller. On the PCB is an RV3028-C7 real-time clock, which uses a mere 45 nA of current and can interact with the second microcontroller through a timer or alarm. When commanded, the powerTimer uses an SR latch as its main control circuit, allowing sin...

Mist, Mirrors, Laser : Multi-view 3D Projection

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“Lights, camera, action!” might have been the call when recording back in the day, but for an awesome three-dimensional viewing experience, you might try yelling “Mist, Mirrors, Laser!” and following in the footsteps of [Ancient]’s latest adventure in voxel displays,  which is also embedded below. He starts with a naive demonstration: take a laser projector and toss an image into a flat cloud of mist. That demonstrates that yes, the mist does resolve an image, and that the viewing angle is very poor– that is, brightness drops off sharply when you’re out of line from the projector. In this case, that’s a good thing! It means more angles can be projected into that mist for a three-dimensional, hologram effect. The optical train gets folded up, probably to make this fit on a tabletop: first, an array of flat mirrors in front of the projector splits the image from the projector into multiple viewpoints, which are each bounced to a second flat mirror that sends the image into the fo...

Hackaday Links: April 26, 2026

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It’s been three weeks since the Artemis II crew returned to Earth, and while the mission might be over for Reid Wiseman, Victor Glover, Christina Hammock Koch, and Jeremy Hansen, the work is only just beginning for engineers back at NASA. In a blog post earlier this week, the space agency went over the preliminary post-mission assessments of the spacecraft and its ground support equipment, and detailed some of the work that’s currently taking place as preparations begin for Artemis III. During Artemis I, higher than expected damage was noted on both the Orion’s heat shield and the Space Launch System (SLS) launch pad. But according to NASA, the changes implemented after that first mission seem to have prevented similar issues this time around. The post also explains that reusable components of the Orion spacecraft, such as the avionics and the crew seats, are already in the process of being removed from Integrity so they can be installed in the next capsule on the production line. ...

A Sail and Oar Skiff Built from Common Lumber

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For those first venturing into sailing, it can be overwhelming since the experience is thick with jargon and skills that don’t often show up in life ashore. With endless choices, including monohulls versus catamarans, fiberglass versus wood, fractional versus masthead rigs, and sloops versus ketches, a new sailor risks doing something like single-handing a staysail schooner when they should have started on a Bermuda-rigged dinghy without a spinnaker. Luckily, there are some shortcuts to picking up the hobby, like the venerable Sunfish or Hobie ships. It’s also possible to build a simple sailing vessel completely out of materials from a local hardware store, as [Cumberland Rover] has been demonstrating . [Cumberland Rover] has a number of homemade vessels under his belt, from various kayaks and rowboats. His latest project is a 12-foot rowboat, which has the option to add a mast and sail. The hull is made from two 1×12 pieces of lumber, bent around a frame and secured. Plywood makes ...

Freeze Moving Tools with a Stroboscopic Camera

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If you take a video of a spinning wheel, you’ll probably notice that the spokes appear to turn more slowly than the wheel is actually rotating, and sometimes in the wrong direction. This is caused by a near match in the frame rate of the camera and the rate of rotation of the wheel – each time the camera captures a frame, the wheel has rotated a spoke into nearly the same position as in the last frame. If you time the exposures carefully, as [Excessive Overkill] did in his latest video , this effect can seemingly freeze moving objects, such as a fan or saw blade. Most cameras only allow relatively coarse, fixed adjustments to frame rate, making it difficult to synchronize the shutter to an object’s motion. To get around this, [Excessive Overkill] used an industrial camera (previously used in this aimbot ), which has fine frame rate control and external triggering. He connected the external trigger to a laser sensor, which detects a piece of retroreflective tape every time it passes b...

Slicer Settings for “Indestructible” Battle-Bot Worthy PLA Parts

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If you follow [Maker’s Muse] on YouTube, you know he’s as passionate about robot fights these days as he is about the tools he uses to make the robots. Luckily for us, he’s still got fame as a 3D printing YouTuber, as this has given him the platform to share his trade secrets for strong, robot-combat-worthy prints . He fights robots in a ‘plastic ant-weight’ division, which restricts not only the weight of the robot but also the materials used. Not only must they be primarily plastic, but only certain plastics are allowed: PLA is in, but engineering filaments, Nylon, and TPU are out. Since necessity is the mother of invention, this has led to strong evolutionary pressure to figure out how to print the most impact-resilient PLA parts for armor and spinners. He’s using the latest OrcaSlicer and shares the profile as a pay-what-you-want 3MF file . It’s all about solidity: a solid part with solidly fused walls and solidly linked layers. It makes sense: if you’re going to be hammering on...