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Showing posts from March, 2026

An Electric Jellyfish For Androids

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We have to admit, we didn’t know that we wanted a desktop electric jellyfish until seeing [likeablob]’s Denki-Kurage , but it’s one of those projects that just fills a need so perfectly. The need being, of course, to have a Bladerunner-inspired electric animal on your desk, as well as having a great simple application for that Cheap Yellow Display (CYD) that you impulse purchased two years ago. Maybe we’re projecting a little bit, but you should absolutely check this project out if you’re interested in doing anything with one of the CYDs . They are a perfect little experimentation platform, with a touchscreen, an ESP32, USB, and an SD card socket: everything you need to build a fun desktop control panel project that speaks either Bluetooth or WiFi. We love [likeablob]’s aesthetic here. The wireframe graphics, the retro-cyber fonts in the configuration mode, and even the ability to change the strength of the current that the electric jellyfish is swimming against make this look so co...

Analog Video From an 8-Bit Microcontroller

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Although the CRT has largely disappeared from our everyday lives, there was a decades-long timeframe when this was effectively the only display available. It’s an analog display for an analog world, and now that almost everything electronic is digital, these amazing pieces of technology are largely relegated to retro gaming and a few other niche uses. [Maurycy] has a unique CRT that’s small enough to fit in a handheld television, but since there aren’t analog TV stations anymore, he decided to build his own with nothing but an 8-bit microcontroller and a few other small parts . The microcontroller in question is a fairly standard 8-bit AVR. These microcontrollers have one major limitation when generating the VHF and UHF radio signals needed for analog TV: their natural clock speed is much too low. The maximum output frequency of a pin on this microcontroller is only 6 MHz, and [Maurycy] needs something about two orders of magnitude faster. To solve this problem, [Maurycy] uses a qui...

Reviving a Cursed Sun SPARCstation IPX

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SPARCstation IPX running Solaris 2.6. (Credit: This Does Not Compute, YouTube) The best part about retro computing is the idea that you’ll save some poor system from being scrapped and revive it to a working state, at which point you can bask in the glory of a job well done. That’s when reality often strikes hard, and you find yourself troubleshooting a maddening list of issues as you question everything about your life choices. Such was the case with [This Does Not Compute] over at YouTube with a Sun SPARCstation IPX that decided to put up a big fight. This is the second video of a series. In the first installment, the PSU was repaired, and a boot failure was diagnosed. The system’s onboard diagnostic led to the assumption that one of the 8 kB SRAM ICs was defective.  You can readily get SRAM replacements, so it seemed to be an easy fix. Unfortunately, the fun was only beginning as the system reported the exact same error after the SRAM was replaced. After flipping a virtua...

ESP32: When Is A P4 A P4, But Not The P4 You Thought It Was

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We’re used to electronic parts of the same type staying predictably the same, sometimes over many years. An early Z80 from the mid 1970s can be exchanged with one from the end of production a few years ago, for example. This week, we’ve had DMs from several readers who’ve found that this is not always the case, and the culprit is surprising. Espressif has released a new revision of their P4 application processor , and though it’s ostensibly the same, there are a couple of changes that have been catching people out. The changes lie in both hardware and software, in that there’s a pin that’s changed from NC to a power rail, a few extra passives are needed, and firmware must be compiled separately for either revision. The problem is that they are being sold as the same device and appear in some places under the same SKU! This is leading to uncertainty as to which P4 revision is in stock at wholesalers. We’ve been told about boards designed for the old revision being assembled with the n...

Slug Algorithm for On-GPU Rendering of Fonts with Bézier Curves now in Public Domain

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The Slug Algorithm has been around for a decade now, mostly quietly rendering fonts and later entire GUIs using Bézier curves directly on the GPU for games and other types of software, but due to its proprietary nature it didn’t see much adoption outside of commercial settings. This has now changed with its author, [Eric Lengyel], releasing it to the public domain without any limitations. Originally [Eric] had received a software patent in 2019 for the algorithm that would have prevented anyone else from implementing it until the patent’s expiration in 2038. Since 2016 [Eric] and his business have however had in his eyes sufficient benefit from the patent, making it unnecessary to hold on to it any longer and retain such exclusivity. To help anyone with implementing their own version of the algorithm, there is a GitHub repository containing reference shader implementations with plenty of inline comments that should help anyone with some shader experience get started. Although pr...

Conway’s Game of Life With Physical Buttons

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Conway’s Game of Life excels in its simplicity, creating a cellular automaton on a 2D grid where each cell obeys a set of very simple rules that determine whether a cell is ‘alive’ or ‘dead’. After setting an initial condition the ‘game’ then evolves naturally from there, creating an endless series of patterns as a simplified form of bacterial evolution. Of course, setting an initial state and then watching cells light up or fade away seems like a natural fit for light-up buttons. After struggling with intrusive thoughts related to such a project for a while, [Michal Zalewski] finally gave in, creating a pretty amazing looking result . Although there is no set size for the game board, [Michal] was constrained by his budget for the selected NKK JB15LPF-JF tactile buttons, resulting in a 17×17 matrix. That’s 289 buttons, for those keeping score, which comes down to over $1,000 over at e.g. Digikey even with quantity-based pricing. Add to this the custom PCB and a Microchip AVR128DA64 s...

How Long Can a Quadcopter Drone Fly on Just Solar?

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The final second prototype flying. (Credit: Luke Maximo Bell, YouTube) The dream of fully powering everything from aircraft to cars on just the power generated from solar panels attached to the machine remains a tempting one, but always seems to require some serious engineering including putting the machine on a crash diet. The quadcopter that [Luke Maximo Bell] tried to fly off just solar power is a good case in point, as the first attempt crashed after three minutes and wrecked its solar panels. Now he’s back with a second attempt that ought to stay airborne for as long as the sun is shining. Among the flaws with the first prototype were poor support for the very thin and fragile PV panels, requiring much better support on the carbon fiber frame of the drone. To support the very large solar array, the first drone’s arms were made to be very long, but this interfered with maneuvering, so the second version got trimmed down and the array raised above the frame. This saved 70 gra...

Studying a Battle Born LFP Battery’s Death Under Controlled Conditions

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The test setup for the Battle Born LFP cycling. (Credit: Will Prowse, YouTube) There has been quite a bit of news recently about the  Battle Born LiFePO 4 (LFP) batteries and how they are dying in droves if not outright melting their plastic enclosures. Although the subsequent autopsies show molten plastic spacers on the bus bars and discolored metal in addition to very loose wiring, it can be educational to see exactly what is happening during repeated charge-discharge cycles at a fraction of the battery’s rated current. Thus [Will Prowse] recently sacrificed another Battle Born 75 Ah LFP battery to the Engineering QA Gods. This time around the battery was hooked up to test equipment to fully graph out the charging and discharging voltage and current as it was put through its paces. To keep the battery as happy as possible it was charged and discharged at a mere 49A, well below its rated 100A. Despite this, even after a mere 14 cycles the battery’s BMS would repeatedly dis...

Real Robot Makes Debut in Programming Game

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Sometimes the right tool for the right job appears almost out of nowhere. That was certainly the case for [Jonathan] who came across an unusual but well-designed robot at a secondhand shop. The robot needed a bit of work to get back into a usable condition, but after that it was ready for use. For such a unique machine, it needed a unique place to work as well, so in this build [Jonathan] uses it as a real robot to recreate a popular board game meant to teach programming to children. In the original board game, called Robot Turtles , there are no actual robots. Instead, players use cards to control turtles to reach objectives in much the same way that a programmer would solve a similar problem with a computer. A board game with such a name almost demands a robot, so [Jonathan] found a larger playing surface in the form of soft matting blocks, each with a number or letter, that can be assembled into a grid. To make the game, he built a Python application on top of the interface h...

Retro Weather Display Acts Like It’s Windows 95

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Sometimes you really need to know what the weather is doing, but you don’t want to look at your phone. For times like those, this neat weather display from [Jordan] might come in handy  with its throwback retro vibe. The build is based around the ESP32-2432S028—also known as the CYD, or Cheap Yellow Display, for the integrated 320 x 240 LCD screen. [Jordan] took this all-in-one device and wrapped it in an attractive 3D-printed housing in the shape of an old-school CRT monitor, just… teenier. A special lever mechanism was built in to the enclosure to allow front panel controls to activate the tactile buttons on the CYD board. The ESP32 is programmed to check Open-Meteo feeds for forecasts and current weather data, while also querying a webcam feed and satellite and radar JPEGs from available weather services. These are then displayed on screen in a way that largely resembles the Windows 95 UI design language, with pages for current conditions, future forecasts, wind speeds, and th...

Reading the World’s Smallest Hard Drive

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You have a tiny twenty-year-old hard drive with a weird interface. How do you read it? If you’re [Will Whang], by reverse engineering, and building an interface board . In many of our portable, mobile, and desktop computers, we’re used to solid-state storage. It’s fast and low power, and current supply-chain price hikes notwithstanding, affordable in the grand scheme of things. It wasn’t always this way though, a couple of decades ago a large flash drive was prohibitively expensive. Hard drive manufacturers did their best to fill the gap with tiny spinning-rust storage devices which led to the smallest of them all: the Toshiba MK4001MTD. It crammed 4 GB onto a 0.85″ platter, and could be found in a few devices such as high-end Nokia phones. Breaking out the Nokia’s hard drive interface. The drive’s connector is a pattern of pads on a flexible PCB, one he couldn’t help noticing had a striking resemblance to an obscure SD card variant. Hooking it up to an SD reader didn’t work unfo...

Running Windows 98 on the iPAQ IA-2 Internet Appliance

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Devices that were limited to only run a web browser were relatively common around 2000, as many people wanted to surf the Information Super Highway, but didn’t quite want to get a regular PC — being in many ways the retro equivalent of a Chromebook. The Compaq iPAQ IA-2 from 2000 that [Dave Luna] got is no exception , with a Microsoft CE-based OS that is meant to be used with Microsoft Network (MSN) dial-up, which amusingly is still available today. In order to get a more useful OS on it, like Windows 98, you have to jump through quite a few hoops, as [Dave] found out. Although there is an IDE connection on the mainboard, this cannot be booted from, likely due to BIOS limitations. This means that he had to chain boot via the 16 MB NAND Flash drive that the original OS booted from, which was done by writing MS-DOS to the Flash drive using another workaround as it’s not a standard IDE device either. From this you can then boot Windows 98 from an IDE drive by pretending that it’s an A...

Repurposing Old AMD APUs For AI Work

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The BC250 is what AMD calls an APU, or Accelerated Processing Unit. It combines a GPU and CPU into a single unit, and was originally built to serve as the heart of certain Samsung rack mount servers. If you know where to find cheap surplus units of the BC250, you can put them to good use for AI work , as [akandr] demonstrates. The first thing you’ll have to figure out is how to take an individual BC250 APU and get it up and running. It’s effectively a full system-on-chip, combining a Zen 2 CPU with a Cyan Skillfish RDNA 1.5 GPU. However, it was originally intended to run inside a rackmount server unit rather than a standalone machine. To get it going, you’ll need to hook it up with power and some kind of cooling solution. From there, it’s a matter of software. [akandr] explains how to get AI workflows running on the BC250 using Ollama and Vulkan, while noting useful hacks to improve performance like disabling the GUI and tweaking the CPU governor. The hardware can be used with a wid...

FLOSS Weekly Episode 866: BreezyBox and Embedded Compilers

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This week Jonathan chats with Valentyn Danylchuk about BreezyBox — an interactive shell and toolkit that provides various tools and a compiler on an ESP32 microcontroller. What was the inspiration for this impressive project, and what direction is it heading? Watch to find out! https://github.com/valdanylchuk/breezydemo https://github.com/valdanylchuk/xcc700 https://www.linkedin.com/in/valdanylchuk https://hackaday.com/2026/02/06/breezybox-a-busybox-like-shell-and-virtual-terminal-for-esp32/ 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 Creative Commons: By Attributi...

How to Grow Large Sugar Crystals

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Many substances display crystallization, allowing them to keep adding to a basic shape to reach pretty humongous proportions. Although we usually tend to think of pretty stones that get fashioned into jewelry or put up for display, sugar also crystallizes and thus you can create pretty large sugar crystals. How to do this is demonstrated by [Chase] of  Crystalverse fame in a recent video. This is effectively a follow-up to a 2022 blog article in which [Chase] showed a few ways to create pretty table sugar (sucrose) based crystals. In that article the growth of single sucrose crystals was attempted, but a few additional crystals got stuck to the main crystal so that it technically wasn’t a single crystal any more. With this new method coarse sugar is used both for seed crystals as well as for creating the syrupy liquid from mixing 100 mL of water with 225 grams of sugar. Starting a single crystal is attempted by using thin fishing wire in a small vessel with the syrup and some...

Zip-Drive Emulator Puts Big Disks Back on LPT

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Iomega’s Zip drives filled an interesting niche back in the 1990s. A magnetic disk that was physically floppy-sized, but much larger in capacity– starting at 100 MB, and reaching 750 MB by the end–they never quite had universal appeal, but never really went away until flash memory chased them out of the marketplace in the early 2000s. While not everyone is going to miss them, some of us still think it’s a better form factor than having a USB stick awkwardly protruding from a computer, or microSD cards that are barely large enough to see with the naked eye. [Minh Danh] is one of those who still has affection for Zip drives, and when his parallel port Zip 100 drive started to give up the ghost last year, he decided to do something bold: reverse engineer it, and produce an emulator. First software , and then in hardware . It’s not the prettiest-ever prototype, but lots of great things start with a mess of wires. The first was to create a virtual zip drive that could run on a virtual ...

Testing a Soviet 1000 Volt Insulation Tester from 1985

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Although the term ‘Iron Curtain’ from the Cold War brings to mind something like the Berlin Wall and its forbidding No Man’s Land, there was still active trade between the Soviet Union and the West. This included devices like the M4100/4 insulation tester that the [Three-phase] YouTube channel recently looked at, after previously poking at a 1967 USSR resistance bridge. This particular unit dates to 1985, and comes in a rather nice-looking case that somewhat looks like bakelite. It’s rated for up to 1 gigaohm, putting out 1,000 V by using the crank handle. Because of the pristine condition of the entire unit, including seals, it was decided to not look at the internals but only test its functionality. After running through the basic usage of the insulation tester it’s hooked up to a range of testing devices, which shows that it seems to be mostly still in working condition. The first issue noticed was that the crank handle-based generator was a bit tired, so that it never quite hit...

Preparing to Fire Up a 90-Year-Old Boiler After Half a Century

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Continuing the restoration of the #1 Lancashire boiler at the Claymills Pumping Station in the UK, the volunteers are putting on the final touches after previously passing the boiler inspection. Although it may seem that things are basically ready to start laying down a fire after the boiler is proven to hold 120 PSI with all safeties fully operating, they first had to reassemble the surrounding brickwork, free up a seized damper shaft and give a lot of TLC to mechanisms that were brand new in the 1930s and last operated in 1971. Removing the ashes from a Lancashire boiler. (Credit: Claymills pumping station, YouTube) The damper shaft is part of the damper mechanism which controls doors that affect the burn rate, acting as a kind of throttle for the boilers. Unfortunately the shaft’s bearings had seized up completely, and no amount of heat and kinetic maintenance could loosen it up again. This forced them to pull it out and manufacture a replacement, but did provide a good look ...

Ternary RISC Processor Achieves Non-Binary Computing Via FPGA

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You would be very hard pressed to find any sort of CPU or microcontroller in a commercial product that uses anything but binary to do its work. And yet, other options exist! Ternary computing involves using trits with three states instead of bits with two. It’s not popular, but there is now a design available for a ternary processor that you could potentially get your hands on. The device in question is called the 5500FP , as outlined in a research paper from [Claudio Lorenzo La Rosa.] Very few ternary processors exist, and little effort has ever been made to fabricate such a device in real silicon. However, [Claudio] explains that it’s entirely possible to implement a ternary logic processor based on RISC principles by using modern FPGA hardware. The impetus to do so is because of the perceived benefits of ternary computing—notably, that with three states, each “trit” can store more information than regular old binary “bits.” Beyond that, the use of a “balanced ternary” system, base...

Recycled Plastic Compression Molding With 3D-Printed Molds

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Recycling plastic at home using 3D printed molds is relatively accessible these days, but if you do not wish to invest a lot of money into specialized equipment, what’s the most minimal setup that you can get away with? In a recent [future things] video DIY plastic recycling is explored using only equipment that the average home is likely to have around. Lest anyone complain, you should always wear PPE such as gloves and a suitable respirator whenever you’re dealing with hot plastic in this manner, just to avoid a trip to the emergency room. Once taken care of that issue, there are a few ways of doing molding, with compression molding being one of the most straightforward types. With compression molding you got two halves of a mold, of which one compresses the material inside the other half. This means that you do not require any complex devices like with injection molding, just a toaster oven or equivalent to melt the plastic, which is LDPE in this example. The scrap plastic is pl...