TechyMagThings

Once you peel back the hype and mysticism, large language models (LLMs) are a fascinating application of statistical models, effectively what you get when you dial a basic auto-complete model up to eleven. In order to analyze a mind-boggling amount of text and produce meaningful auto-completion results quite a bit of math is involved, with a recent three-part article series by [Giles] going through the basics of inference, being the prediction step using a trained model.

The text is encoded in the LLM’s vector space as token IDs, each token being a text fragment that has some probability of following another ID, such as when cats may be found on desks, as in the above photo by [Giles]. With inference multiple of such IDs are retrieved in a vector from which in successive steps a sentence can be pieced together. These so-called logits are detailed in the first article in the series, with the second article focusing on vocabulary space and embedding, as well as the matrix operations used for inference.

Finally, the third article puts all of this together and looks at transformers, which is a crucial part of GPT (generative pretrained transformer) LLM architecture. Of note is the attention mechanism, which takes GPTs beyond merely being glorified auto-complete systems by adding pattern matching. Here we can see how the statistical model of the LLM is used to generate a rather plausible output, which is where the human has to ask themselves in how far they feel that it is correct.

Of course, there goes a lot more into making LLMs and GPTs performant, such as key-value caches that massively speed up inference.

The Iranian Shahed-136’s basic design has seen many changes and additions since Russia began using them, with some featuring interesting payloads such as cameras in a gimbal, making these drones useful for tasks like surveillance. Recently [Michel] got his hands one one such camera that was recovered from a shot-down drone in Ukraine, providing the opportunity for an in-depth look at what hardware is in these cameras.

The teardown thus covers the gimbal mechanism itself as well as the electronics and camera. First up is an Artix-7 FPGA-based board, followed by the range finder assembly. Unsurprisingly the camera feed handling is performed by an Hi3519 SoC, as this appears to be the off-the-shelf option you find all over on AliExpress and similar sites. There’s also an Artix-7 FPGA-based board here, which presumably performs some machine vision tasks or similar.

Continuing the ‘bought off AliExpress’ vibe, the power supply board (pictured above) is quite literally just that. A relay board follows the same pattern, with apparently the entire contents of the camera consisting of off-the-shelf development boards and modules that are readily found for sale online.

For the camera there is a thermal camera presumably for night operations, as most of these drone swarms are launched towards Ukraine at night. Looking at the gimbal assembly it similarly feels like it was sourced off AliExpress, featuring mostly Western components, sometimes with the typical lasered-off component markings and such.

This makes one wonder how much has changed here since nearly two years ago we saw an air data computer from a similar drone that could have been sourced off AliExpress, while the Russian missile teardowns show significantly more custom hardware, presumably because those are harder to source off AliExpress.

When life gives you lemons, you make lemonade. What if life gives you a pile of old e-book readers? Well, when [spiritplumber] got box of old Nook Simple Touch devices, he decided to design solar-powered cases to help boost the old batteries. It makes perfect sense to us: sunlight readable screen, sunlight chargeable battery.

It looks like he’s got a pair of panels built into the 3D printed case. He recommends using any TP4056-based charger, and tying into the battery test points, not the 5 V supply. It won’t hurt anything if you do, apparently, but the device will think it’s plugged in an refuse to turn off the WiFi. That’s no big deal when you’ve got a continental power grid on the other end of the cable, but charging from a small panel on the back of the case doesn’t always give you enough juice to waste on unneeded radio activity. Especially indoors — these panels are apparently big enough to trickle-charge the device under artificial light, which is a nice, if doubtless slow feature.

The design is open source, and includes SketchUp design files as well as the exported .STL, so if you’ve got a hankering to edit this to fit a different e-book reader, you can. He also provides a handy-dandy guide to root this model of Nook, and if you’re on Hackaday we probably don’t need to explain why you might want to.

We’ve seen the Nook Simple Touch go some interesting places — like into the clouds as a glider computer — but solar power is a new hack for this device, at least on this site. We don’t know if [spiritplumber] has a green thumb, but he’s evidently got some environmental bones in his body: his last featured project was about improving quadcopter efficiency with a wing and a prayer.

The ionosphere is of great importance to shortwave radio transmissions, since it allows radio waves to be refracted and reflected over the horizon, and it’s therefore unfortunate that the height and thickness of the ionosphere depends on the time of day or night, weather, season, and the solar cycle. To get a better idea of current transmission conditions, [mircemk] built this shortwave propagation monitor.

The monitor provides a basic measure of ionosphere conditions by measuring the strength of received shortwave signals: if the conditions for transmission are good, it should receive a relatively high level of existing signals, and a weak signal if conditions are bad. It has an external antenna connected to a signal strength indicator circuit based on the CA3089, which amplifies signals in the 1-40 MHz range and outputs a smoothed voltage indicating the RF energy in this range. The output signal can be read by any voltmeter, in this case an Arduino Nano with an OLED display. Assuming the same antenna is always used, the signal should noticeably fluctuate between night and day as the solar wind affects the ionosphere.

Of course, the distance at which you’ll be receiving a signal means nothing unless you have a receiver, which can range from the antique to the modern.

Although modern cameras can, with skill and good conditions, produce photographs nearly indistinguishable from the original scene, this fidelity relies on the limitations of human vision. According to the trichromatic theory, humans perceive light as a mixture of three colors, which can be recorded and represented by cameras, displays, and color printing; a spectrometer, however, can detect a clear distance between the three colors present in a photograph and the wide range of spectra in the original scene. By contrast, one of the earliest color photography methods, Lippmann plates, captured not just true color, but true spectra.

A Lippmann plate, as [Jon Hilty] details, starts with a layer of photographic gel containing extremely fine silver halide crystals over the back of a glass plate. This layer is placed on top of a mirror, traditionally a mercury bath, and put in the camera. When light passes through the emulsion and reflects off the mirror, it interferes with incoming light to create a standing wave. The portions of the emulsion at the wave’s antinodes absorb the most energy, converting local silver halide crystals into reflective silver. The spacing of the silver particles depends on the incoming light’s wavelength, and is fixed in place during the development process.

This creates a matrix of vertically-stacked diffraction gratings, each diffracting back the original wavelength when illuminated with white light. Unlike normal diffraction gratings, the wavelength of diffracted light doesn’t depend strongly on the viewing angle; since the interference structure here is vertically-arranged, it refracts a narrow range of wavelengths across all possible viewing angles. The viewing angles, however, are limited; unlike with dye-based photographs, you can only view the colors nearly straight-on. This, along with the necessity for long exposures, the chance of producing washed-out colors, and the impossibility of creating reprints, kept Lippmann plates from ever really catching on. The basic concept lives on in holograms, which encode spatial information in a similar kind of photographically-formed diffraction pattern.

For a more conventional method of color photography, we’ve also seen a recreation of the autochrome method. Alternatively, check out this homemade silver halide photography emulsion.

Thanks to [Stephen Walters] for the tip!

Although the ReactOS project is in no rush to dethrone Windows as the desktop operating system of choice, this doesn’t mean that some real changes aren’t happening. Most recently two big changes got merged, the first pertaining to the separate boot- and live CD images that are now merged into a single image, and the second being a new PnP-aware ATA storage stack for ATA and AHCI devices, with NT6+ compatibility.

Although there is still a separate live CD for now, this first change means that testing and installing ReactOS becomes easier, and that the old-school text-based installer may soon be on its way out as well.

Having the new ATA storage stack in place will translate into much better compatibility with real hardware, including the ability to use more hardware to install on and boot from compared to the old UniATA driver.

Combined, these two changes should bring the ReactOS installation and usage experience a lot closer to that of Windows, as well as many Linux distros. If you had issues with the OS on real hardware, this might be just the right time to give it another shake and provide detailed feedback to the developers if any remaining issues are encountered.

Thanks to [jeditobe] for the tip.

Software that collects public data from the Internet and uses it to provide half-assed answers to your questions might seem like a modern craze, but today we bid farewell to a website that helped pioneer pretend conversations all the way back in 1997 — as of May 1st, Ask Jeeves is no more.

Well, technically they dropped the “Jeeves” part back in 2006. Since then it’s just been Ask.com, but as the name implies the idea was more or less the same. Rather than the relatively rigid parameters and keywords required by traditional search engines, you could ask Jeeves questions about the world using natural language. Early advertisements showed the virtual valet answering arbitrary questions like “How many calories in a banana?,” which of course today seems commonplace and utterly unimpressive, but was a pretty wild for the 1990s.

It might seem surprising that a site designed from day one to offer a human-like Q&A experience should fold right as such technology is becoming commonplace. But of course, that commonality is the problem. When Google can answer your questions just as well (or poorly…) as Jeeves or anyone else, what’s the benefit for the average Internet user to seek out another service? But it’s still somewhat ironic, which is probably why the farewell message on Ask.com ends with the line “Jeeves’ spirit endures.”

While on the subject of technology that’s potentially ahead of its time, MacRumors is reporting that Apple is giving up on their Vision Pro augmented reality googles. They haven’t been formally discontinued as of yet, but sources indicate that the internal development team for the entire product line has been disbanded and reassigned to other projects within the company. This comes after a October 2025 refresh of the hardware still failed to connect with consumers. Insiders have said that not only were sales sluggish on the ~$3,500 headsets, but that they were getting returned at a far higher rate than any of Apple’s other hardware products.

Now, we’re hardly Apple apologists here at Hackaday. It sort of goes without saying that the whole “Walled Garden” thing doesn’t really fit our ethos. But we can’t deny that the Vision Pro is an impressive piece of technology. After years of sticking our phones in crappy plastic headsets, or trying to force hardware designed for VR gaming to do literally anything else, the Vision Pro offered a practical way to put augmented reality to work. But even for a company known for producing expensive hardware, the price tag was just too much for most consumers.

We’ll go out on a limb here and predict that the Vision Pro will one day be looked back on like the Newton — a product that was too expensive and niche to be a commercial success when it came out, but still a technical milestone that gave us a glimpse into the shape of things to come.

Speaking of a technology that will inevitably become more common, the European Patent Office (EPO) released a report this week showing a seven-fold increase in the number of inventions intended for battery reuse and recycling over the last decade. Given our insatiable demand for rechargeable batteries, it should come as no surprise that there’s a huge push for new methods of squeezing more use out of cells. As noted several times by the EPO, it’s not purely about saving money either. Even if Europe produces the batteries domestically, they need to import the raw materials. Relying on foreign countries to provide critical infrastructure can be precarious in the best of times, and is likely to only become more politically onerous in the future.

Finally, we’ll leave you with a fun way to waste some time on a Sunday evening: Visible Zorker. Created by Andrew Plotkin, this website allows you to not only play through all three installments of Zork, but presents a debugger-style view of the source code as the game is running. Even if you’re not terribly interested in seeing how your responses are parsed, the map that shows your progress through the world is certainly handy. The project was actually started back in 2025, but Andrew just completed the trilogy by adding support for Zork III a couple days ago so now is the perfect time to check it out.

See something interesting that you think would be a good fit for our weekly Links column? Drop us a line, we’d love to hear about it.