We know, you’ve already got a USB to serial adapter. Probably several of them, in fact. But that doesn’t mean you couldn’t use one more — especially when it’s as as cleverly designed as this one from [Anders Nielsen].
The first thing you notice about this adapter, and the big departure from the ones that are likely littering your parts bin, is that it terminates in a full-size male DSUB9 connector. With the ability to be directly plugged into a RS-232 port, this adapter will certainly catch the eye of retrocomputer enthusiasts. With a clever arrangement of jumpers, you can even reconfigure the RX and TX lines to be straight-through or cross over as needed.
But if you’re working with something that doesn’t have a literal serial port, no worries. All of the lines coming from the CH340G chip are broken out to a header so you can connect it up to whatever device you’re working with via jumpers.
In fact, if you’re really sure you’ll never need that RS232 feature, the PCB is even designed in such a way that you can simply snap it off. Admittedly it might seem a little odd to get a device like this if you didn’t want that capability. But once broken off, it’s not like the components go to waste. [Anders] has designed the board in such a way that if you flip it over and install a right-angle header, you can use the RS232 segment on a breadboard.
But the list of features doesn’t stop there. There’s also a 3.3 V regulator on board that you can use to power external circuits, as well as breakouts for the data lines in the USB-C connector. In keeping with the theme of the device, that part of the PCB can also be snapped off if you want to use it elsewhere.
Most folks probably’ won’t need all the capabilities offered by this particular serial adapter, and that’s fine. We’re still happy that it’s out in the wild and available for the community to use and adapt as an open source project.
You wouldn’t typically associate graphing calculators with artificial intelligence, but hacker [KermMartian] recently made it happen. The innovative project involved running a neural network directly on a TI-84 Plus CE to recognize handwritten digits. By using the MNIST dataset, a well-known collection of handwritten numbers, the calculator could identify digits in just 18 seconds. If you want to learn how, check out his full video on it here.
The project began with a proof of concept: running a convolutional neural network (CNN) on the calculator’s limited hardware, a TI-84 Plus CE with only 256 KB of memory and a 48 MHz processor. Despite these constraints, the neural network could train and make predictions. The key to success: optimizing the code, leveraging the calculator’s C programming tools, and offloading the heavy lifting to a computer for training. Once trained, the network could be transferred to the calculator for real-time inference. Not only did it run the digits from MNIST, but it also accepted input from a USB mouse, letting [KermMartian] draw digits directly on the screen.
While the calculator’s limited resources mean it can’t train the network in real-time, this project is a proof that, with enough ingenuity, even a small device can be used for something as complex as AI. It’s not just about power; it’s about resourcefulness. If you’re into unconventional projects, this is one for the books.
Most people know about the numerical constant pi (or π, if you prefer). But did you know that pi has an evil twin represented by the symbol ϖ? As [John Carlos Baez] explains, it and its related functions are related to the lemniscate as pi relates to circles. What’s a lemniscate? That’s the proper name for the infinity sign (∞).
[John] shows how many of the same formulas for pi also work for the lemniscate constant (the name for ϖ). Some (as John calls them) “mutant” trig functions use the pi-like constant.
Mathematically, a circle is a point (the center) with a curve that describes x2+y2=r2. The lemniscate is a particular instance of a Cassini oval where r2=cos2θ. We all know the circumference of a circle—basically, the perimeter—is 2π; the perimeter of the lemniscate is 2ϖ.
Why does any of this matter? Well, [John] shows how it connects to elliptic curves and the Gauss constant.
Like pi, the lemniscate constant probably never ends, but it is roughly 2.622057. Will this be useful in your next project? Probably not. Will it help you win some bar bets? Maybe.
If we’ve learned anything over the years, it’s that the only thing hardware hackers love more than a device festooned with buttons is one that’s covered in LEDs — so it’s no surprise that this “Mr Christmas” jukebox caught the eye of [Roberts Retro]. But while the holiday gadget might have been mildly entertaining in its stock configuration, he quickly realized that what it really needed was an ESP32 retrofit. After all, what good are all those buttons and LEDs if you can’t bend them to your will?
For the first half of the video, [Robert] treats us to a detailed teardown of the device, which as you might imagine, is largely hollow inside. This gave him plenty of room to graft in new hardware, which is really the best gift any of us could hope to find under the tree. In addition to the ESP32 development board, the jukebox also received a number of WS2812B addressable RGB LEDs, and a DFPlayer module to handle music playback.
With all the buttons wired up to inputs on the ESP32, [Robert] can reconfigure the jukebox to do pretty much whatever he wants with just changes to the software. In the video, he demonstrates how the buttons can be used to trigger the playback of individual songs stored on the DFPlayer’s SD card, which essentially replicates it’s stock functionality. A few lines of changed code later, those same buttons can be used to control devices via Home Assistant.
We all know and love the humble seven-segment display, right? And if you want to make characters as well as numbers, you can do an okay job with sixteen segments off the shelf. But if you want something more art-deco, you’ll probably want to roll your own. Or at least, [Ben] did, and you can find his designs up on GitHub.
Taking inspiration from [Posy]’s epic investigation of segmented displays, [Ben] sat down with a sketchpad and created his own 20-segment font that displays numbers and letters with some strange, but frankly lovely, segment shapes. There is no center line, so letters like “T” and numbers like “1” are a little skewed, but we think it’s charming.
An unfortunate reality of pre-1990s computer systems is that any manuals and documentation that came with them likely only existed on paper. That’s not to say there aren’t scanned-in (PDF) copies of those documents floating around, but with few of these scans being indexable by search engines like Google and Duck Duck Go, they can be rather tricky to find. That’s where the Manx catalog website seeks to make life easier. According to its stats, it knows about 22,060 manuals (9,992 online) across 61 websites, with a focus on minicomputers and mainframes.
The code behind Manx is GPL 2.0 licensed and available on GitHub, which is where any issues can be filed too. While not a new project by any stretch of the imagination, it’s yet another useful tool to find a non-OCR-ed scan of the programming or user manual for an obscure system. As noted in a recent Hacker News thread, the ‘online’ part of the above listed statistics means that for manuals where no online copy is known, you get a placeholder message. Using the Bitsavers website along with Archive.org may still be the most pertinent way to hunt down that elusive manual, with the Manx website recommending 1000bit for microcomputer manuals.
Have you used the Manx catalog, or any of the other archiving websites? What have been your experiences with them? Let us know in the comments.
[Filip] got his hands on a sweet old Hammond X5 organ, but it had one crucial problem: only half of the keys worked. Each and every C#, D, D#, E, F, and F# would not play, up and down the keyboard, although the other notes in between sounded just fine.
Those of you with an esoteric knowledge of older electric organs will be saying “it’s a busted top-octave generator chip”, and you’re right. One of the TOGs worked, and the other didn’t. [Filip] rolled his own top-octave generator with a Pico, in Python no less, and the old beauty roared to life once more.
But what is a top-octave generator, you may ask? For a brief period of time in the early 70s, there were organs that ran on square waves. Because a musical octave is a doubling or halving of frequency, you can create a pitch for every key on the organ if you simply create one octave’s worth of pitches, and divide them all down using something as simple as a binary counter IC. But nobody makes top-octave chips any more.
We love how [Filip]’s design leans heavily on the Pico’s programmable input/output hardware modules to get the job done with essentially zero CPU load, allowing him to write in Python and entirely bypassing the cycle-counting and assembly language trickery. The voltage shifters and the switchable jumpers to swap between different top-octave chip types are a nice touch as well. If you have an organ that needs a top-octave chip in 2024, this is the way we’d do it. (And it sounds fantastic.)
To celebrate the twentieth anniversary of their Trinitron line of televisions, Sony launched the KX-45ED1. At forty three inches the screen on this particular model made it the largest tube television in the world, and it came with the kind of price tag that if you need to ask…you can’t afford it (likely around $100,000 USD today). Three decades later, only two of these mythical displays were thought to exist and [shank] chronicled his quest to acquire one of the last remaining “Big Boys” in the mini documentary below.
As it turns out, one of these gigantic tube televisions was located on the second floor of a restaurant in Japan still sitting in the same place it was installed in 1989. It hadn’t moved in the intervening decades, because the television and its specialized support stand weighed over 500 pounds. Having an object that heavy physically moved down a flight of stairs would seem to be the most formidable challenge for most, but compounding the issue for [shank] was that the building housing this colossal CRT was set to be permanently closed in less than a week.
With next to no time to arrange an international flight, [shank] utilized the power of internet to ask for help from anyone currently living near the “Big Boy” CRT’s soon-to-be final resting place. It just so happened that a fellow retro tech enthusiast based in Japan saw the post, and traveled over an hour by train at a moment’s notice to aid [shank]. The heartwarming story of total strangers united by a common interest of preserving a rare piece of tech history is certainly worth a watch. Let alone the goofy size comparison footage of the smallest CRT display sitting on top of the biggest one.
For more on tube TVs and the like, check out this article by Dave on retro gaming on CRT displays.
[Corelatus] said recently that “someone” asked them to identify the phone signals in the 1982 film The Wall, based on the Pink Floyd song of the same name. We suspect that, like us, that someone might have been more just the hacker part of the brain asserting itself. Regardless, the detective work is fascinating, and you can learn a lot of gory details about phone network in-band signaling from the post.
The analysis is a bit more difficult because of the year the film was made. At that time, different countries used slightly different tone signaling standards. So after generating a spectrogram, the job was to match the tones with known standards to see which one best fit the data.
The signal was not common DTMF, as you might have guessed. Instead, it was a standard known as SS5. In addition to the tones being correct, the audio clip seemed to obey the SS5 protocol. SS5 was the technology attacked by the infamous blue box back when hacking often meant phone phreaking.
The same phone call appears on the album, and others have analyzed it with some even deeper detective work. For example, the call was made in 1979 from a recording studio by [James Guthrie], who called his own phone in the UK, where his next-door neighbor had instructions to hang up on the operator repeatedly.
If you want to see and hear the entire clip (which has several phone-related audio bits in it), watch the video below. The sequence of SS5 tones occurs at 3:13.
Game Boys have a link cable that lets two of them play together. You know, to battle with a friend’s Pokemon and stuff like that. But who says that it should be limited to transmitting only what Big N wants you to?
[Chromalock] wrote a custom GB program that takes in data over the link cable, and displays it on the screen as video, as fast as it can be sent. Add in a microcontroller, a level shifter, and software on the big computer side, and you can hook up your Game Boy Color as a normal video device and send it anything you want, from a webcam to any program that outputs video.
Well, almost. The biggest limitation is the data link cable, of course. On the older Game Boys, the link cable is apparently only good for 8 kHz, while the Color models can pull a not-quite-blistering 512 kHz. Still, that’s enough for 60 fps in a low-res black and white mode, or a slow, screen-tearing high-res color experience. You pick your poison.
There are gotchas that have to do with the way the GB displays palettes that get left as “to-do” on the software side. There is room for improvement in hardware too. (GB Link looks like SPI to us, and we’d bet you can push the speeds even higher with clever GB-side code.) In short, this is an awesome demo that just invites further hacking.
If you want to know more about the Game Boy to get started, and maybe even if you don’t, you absolutely must watch The Ultimate Game Boy Talk. Trust us on this one.
Although the US’ Moon landings were mostly made famous by the fact that it featured real-life human beings bunny hopping across the lunar surface, they weren’t there just for a refreshing stroll over the lunar regolith in deep vacuum. Starting with an early experimental kit (EASEP) that was part of the Apollo 11 mission, the Apollo 12 through Apollo 17 were provided with the full ALSEP (Apollo Lunar Surface Experiments Package). It’s this latter which is the subject of a video by [Our Own Devices].
Despite the Apollo missions featuring only one actual scientist (Harrison Schmitt, geologist), these Bendix-manufactured ALSEPs were modular, portable laboratories for running experiments on the moon, with each experiment carefully prepared by scientists back on Earth. Powered by a SNAP-27 radioisotope generator (RTG), each ALSEP also featured the same Central Station command module and transceiver. Each Apollo mission starting with 12 carried a new set of experimental modules which the astronauts would set up once on the lunar surface, following the deployment procedure for that particular set of modules.
Although the connection with the ALSEPs was terminated after the funding for the Apollo project was ended by US Congress, their transceivers remained active until they ran out of power, but not before they provided years worth of scientific data on many aspects on the Moon, including its subsurface characteristics and exposure to charged particles from the Sun. These would provide most of our knowledge of our Moon until the recent string of lunar landings by robotic explorers.
Heading image: Apollo Lunar Surface Experiments Package of the Apollo 16 mission (Credit: NASA)
You can buy motorized camera sliders off-the-shelf, but they’re pretty costly. Alternatively, you can make one yourself, and it’s not even that hard if you’re kitted out with a 3D printer. [Creative 3D Printing] did just that with a nifty design that adds rotation into the mix. Check it out in the video below.
The basic slider is built out of 3D-printed components and some good old aluminum extrusion. A small 12-volt motor trucks the camera cart back and forth using a leadscrew. It’s torquey enough and slow enough that there isn’t much need for more advanced control—the motor just does the job. There’s also a limit switch set up to trigger a neat auto-reverse function.
The neat part, though, is the rotational mechanism. A smooth steel rod is attached to the slider’s housing, which can be set up in a straight line or aligned diagonally if desired. In the latter case, it rotates the mounting on the camera cart via a crank, panning the camera as it moves along the slider’s trajectory.
It’s a mechanically sophisticated design and quite unlike most of the camera sliders we feature around these parts.
Rope-climbing robots are the stuff of engineering dreams. As kids, didn’t we all clutter our family home with constructions of towers and strings – Meccano, or Lego – to have ziplines spanning entire rooms? Good for the youngsters of today, this has been included in school curricula. At the University of Illinois, the ME 370 students have been given the task of building a robot that can hang from a rope and walk across it—without damaging the rope. The final projects show not only how to approach tricky design problems, but also the creative solutions they stumbled upon.
Imagine a tiny, rope-climbing walker in your workshop—what could you create?
The project is full of opportunities for those thinking out of the box. It’s all about the balance between innovation and practicality: the students have to come up with a solution that can move at least 2 meters per minute, fits in a shoebox, and has some creative flair—no wheels allowed! The constraints provide an extra layer of challenge, but that’s where the fun lies. Some students use inverted walkers, others take on a more creature-like approach. The clever use of motors and batteries shows just how far simple tech can go when combined with a bit of engineering magic.
This project is a fantastic reminder that even small, seemingly simple design challenges can lead to fascinating creations. It invites us adults to play, and by that, we learn: a win-win situation. You can find the original article here, or grab some popcorn and watch the video below.
There are many retrocomputer emulation projects out there, and given the relative fragility of the original machines as they enter their fifth decade, emulation seems to be the most common way to play 8-bit games. It’s easy enough to load one on your modern computer, but there are plenty of hardware options, too. “The computer we’d have done anything for back in 1983” seems to be a phrase many of them bring to mind, but it’s so appropriate because they keep getting better. Take [Stormbytes1970]’s Pi Pico-powered Sinclair ZX Spectrum mini laptop (Spanish language, Google Translate link), for example. It’s a slightly chunky netbook that’s a ZX Spectrum, and it has a far better keyboard than the original.
On the PCB is the Pico, the power supply circuitry, an SD card, and a speaker. But it’s when the board is flipped over that the interesting stuff starts. In place of the squidgy rubber keyboard of yore, it has a proper keyboard,. We’re not entirely sure which switch it uses, but it appears to be a decent one, nevertheless. The enclosure is a slick 3D-printed sub-netbook for retro gaming on the go. Sadly, it won’t edit Hackaday, so we won’t be slipping one in the pack next time we go on the road, but we like it a lot.
It’s not the first Spectrum laptop we’ve covered, but we think it has upped the ante over the last one. If you just want the Spectrum’s BASIC language experience, you can try a modern version that runs natively on your PC.
Ham radio enthusiasts, people looking to borrow their neighbors’ WiFi, and those interested in decoding signals from things like weather satellites will often grab an old satellite TV antenna and repurpose it. Customers have been leaving these services for years, so they’re pretty widely available. But for handheld operation, these metal dishes can get quite cumbersome. A 3D-printed satellite dish like this one is lightweight and small enough to be held, enabling some interesting satellite tracking activities with just a few other parts needed.
Although we see his projects often, [saveitforparts] did not design this antenna, instead downloading the design from [t0nito] on Thingiverse. [saveitforparts] does know his way around a satellite antenna, though, so he is exactly the kind of person who would put something like this through its paces and use it for his own needs. There were a few hiccups with the print, but with all the 3D printed parts completed, the metal mesh added to the dish, and a correctly polarized helical antenna formed into the print to receive the signals, it was ready to point at the sky.
The results for the day of testing were incredibly promising. Compared to a second satellite antenna with an automatic tracker, the handheld 3D-printed version captured nearly all of the information sent from the satellite in orbit. [saveitforparts] plans to build a tracker for this small dish to improve it even further. He’s been able to find some satellite trackers from junked hardware in some unusual places as well. Antennas seem to be a ripe area for 3D printing.
[Lonyelon] wanted to build an anniversary gift for his girlfriend. He decided to say it with e-Paper, a wise choice given its persistence and longevity.
The project is an anniversary calendar. It displays a counter of the total time the couple has been together, measured in years, months, days, and hours—so it’s remarkably precise. [Lonyelon] also programmed it to display additional counters to create plenty of additional fun anniversaries—the couple can celebrate milestones like their 1000th day together, for example. It also cycles through a range of cute messages and displays photos of the couple together.
The code is on Github for the curious. The build is based around a LilyGO e-Paper display with an onboard ESP32 microcontroller. [Lonyelon] paired this with a 2,500 mAh battery. It lasts for ages because the device is programmed to update only every 20 minutes, spending the rest of its time in deep sleep. Since it’s an e-Paper display, it uses zero power when it’s not being updated, so it’s the perfect technology for this application.
It’s a simple project that comes from the heart—the core of any beautiful gift. In fact, some of the coolest projects we feature were built as gifts for romantic partners, family members, or even our fellow hackers. If you’ve been cooking up your own neat build, please let us know on the tipsline!
Multiplication on a common microcontroller is easy. But division is much more difficult. Even with hardware assistance, a 32-bit division on a modern 64-bit x86 CPU can run between 9 and 15 cycles. Doing array processing with SIMD (single instruction multiple data) instructions like AVX or NEON often don’t offer division at all (although the RISC-V vector extensions do). However, many processors support floating point division. Does it make sense to use floating point division to replace simpler division? According to [Wojciech Mula] in a recent post, the answer is yes.
The plan is simple: cast the 8-bit numbers into 32-bit integers and then to floating point numbers. These can be divided in bulk via the SIMD instructions and then converted in reverse to the 8-bit result. You can find several code examples on GitHub.
Since modern processors have several SIMD instructions, the post takes the time to benchmark many different variations of a program dividing in a loop. The basic program is the reference and, thus, has a “speed factor” of 1. Unrolling the loop, a common loop optimization technique, doesn’t help much and, on some CPUs, can make the loop slower.
Converting to floating point and using AVX2 sped the program up by a factor of 8X to 11X, depending on the CPU. Some of the processors supported AVX512, which also offered considerable speed-ups.
This is one of those examples of why profiling is so important. If you’d had asked us if converting integer division to floating point might make a program run faster, we’d have bet the answer was no, but we’d have been wrong.
As CPUs get more complex, optimizing gets a lot less intuitive. If you are interested in things like AVX-512, we’ve got you covered.
Camera sliders are a popular project for makers—especially those who document their projects on video. They’re fun and accessible to build, and they can really create some beautiful shots. [Lechnology] set about to follow in this fine tradition and built a rather capable example of his own. Check it out in the video below.
The slider relies on V-slot rails, perhaps most familiar for their heavy use in modern 3D printers. The rails are paired with a 3D-printed camera carriage, which runs on smooth rubber rollers. A chunky stepper motor provides drive via a toothed belt. Trinamic motor controllers were chosen for their step interpolation feature, making the motion much smoother.
The slider doesn’t just move linearly, either. It can rotate the camera, too, since it has an additional motor in the carriage itself. In a nice retro touch, the wires for this motor are run with an old coiled telephone cable. It’s perfect for the job since it easily extends and retracts with the slider’s motion. Controlling everything is an Arduino, with speed and rotational modes set via a tiny screen and a rotary encoder control.
Early Monday morning, while many of us will be putting the finishing touches — or just beginning, ahem — on our Christmas preparations, solar scientists will hold their collective breath as they wait for word from the Parker Solar Probe’s record-setting passage through the sun’s atmosphere. The probe, which has been in a highly elliptical solar orbit since its 2018 launch, has been getting occasional gravitational nudges by close encounters with Venus. This has moved the perihelion ever closer to the sun’s surface, and on Monday morning it will make its closest approach yet, a mere 6.1 million kilometers from the roiling photosphere. That will put it inside the corona, the sun’s extremely energetic atmosphere, which we normally only see during total eclipses. Traveling at almost 700,000 kilometers per hour, it won’t be there very long, and it’ll be doing everything it needs to do autonomously since the high-energy plasma of the corona and the eight-light-minute distance makes remote control impossible. It’ll be a few days before communications are re-established and the data downloaded, which will make a nice present for the solar science community to unwrap.
While Parker has been in a similar position on previous orbits and even managed a fortuitous transit of a coronal mass ejection, this pass will be closer and faster than any previous approach. It’s the speed that really grabs our attention, though, as Parker will be traveling at a small but significant fraction of the speed of light for a bit. That makes us wonder if there was any need for mission planners to allow for relativistic effects. We’d imagine so; satellite navigation systems need to take relativity into account to work, and they don’t move anywhere near as fast as Parker. Time will be running slower for Parker at those speeds, and it sure seems like that could muck things up, especially regarding autonomous operation.
Ever since the seminal work of Cameron, Hamilton, Schwarzenegger, et al, it has been taken as canon that the end of humanity will come about when the moral equivalent of SkyNet becomes self-aware and launches all the missiles at once to blot us out with a few minutes of thermonuclear fire. But it looks like AI might be trying to raise an army of grumpy teenagers if this lawsuit over violence-inciting chatbots is any indication. The federal product liability lawsuit targets Character.AI, an outfit that creates LLM-powered chatbots for kids, for allegedly telling kids to do some pretty sketchy stuff. You can read the details in the story, but suffice it to say that one of the chatbots was none too pleased with someone’s parents for imposing screen time rules and hinted rather strongly about how the child should deal with them. The chat logs of that interaction and others that are part of the suit are pretty dark, but probably no darker than the advice that most teenagers would get online from their carbon-based friends. That’s the thing about chatbots; when an LLM is trained with online interactions, you pretty much know what’s going to come out.
In today’s “Who could have seen that coming?” segment, we have a story about how drivers are hacked by digital license plates and are keen to avoid tolls and tickets. The exploit for one specific brand of plate, Reviver, and while it does require physical access to the plates, it doesn’t take much more than the standard reverse engineering tools and skills to pull off. Once the plates are jailbroken — an ironic term given that license plate manufacturing has historically been a prison industry — the displayed numbers can be changed at will with a smartphone app. The worst part about this is that the vulnerability is baked right into the silicon, so there’s nothing to be patched; the plates would have to be recalled, and different hardware would need to be reissued. We’ve been skeptical about the need for these plates from the beginning and questioned why anyone would pay extra for them (last item). But maybe the ability to dump your traffic cam violations into someone else’s lap is worth the extra $20 a month.
And finally, this local news story from Great Falls, Montana, is a timely reminder of how machine tools can mess up your life if you let them. Machinist Butch Olson was alone at work in his machine shop back on December 6 when the sleeve of his jacket got caught in a lathe. The powerful machine pulled his arm in and threatened to turn him to a bloody pulp, but somehow, he managed to brace himself against the bed. He fought the lathe for 20 whole minutes before the motor finally gave out, which let him disentangle himself and get some help. He ended up with a broken back, four fractured ribs, and an arm that looks “like hamburger” according to his sister. That’s a high price to pay, but at least Butch gets to brag that he fought a lathe and won.