TechyMagThings

How fast can you count to a million? It would probably take you a while. A computer could certainly do it faster. Indeed, the The National Museum of Computing figured it could actually prove to be a simple but useful benchmark for comparing computers over many eras and architectures. Thus was born the Million Measure.

The intention was to develop a benchmark that could run on just about anything considered a “computer.” As explained in a recent talk, the Million Measure can be run quite simply on anything from an ancient World War II computer like Colossus, to a modern Raspberry Pi. There are no complicated algorithms that need optimization, nor architecture-specific code required to do the job. The museum also found it to be a useful way to figure out which computers in their collection were actually working at any given time. Early computers from the mid-20th century reported benchmark times in minutes, while a 1995 BeBox is the fastest machine tested so far at 0.004 seconds.

It’s not a particularly useful measure for modern machines, which are so fast as to make the test difficult to parse in an intuitive way. But if you’re working with today’s hardware, there are other techniques you can use. Video after the break.

[Thanks to Dave Wild for the tip!]

One of the most hilarious things you can do with an LLM-based chatbot is to ask it to do calculations. If it’s a well-written chatbot frontend, it can detect requests for arithmetic – like summing 1 and 1 – and pass it on to a dedicated calculator application, even if still cannot correctly count the ‘r’s in ‘strawberry’. This is where [Alvaro Videla] asks the question whether it is at all possible to perform arithmetic with a language model.

Since an LLM at its core is nothing but a vector space of probabilities that a matrix-based inference process uses to create a probabilistic output of tokens you’d not expect a lot of deterministic behavior. How can you do arithmetic without grounding it in some kind of deterministic process?

This is where [Alvaro]’s Rune project comes into play, which is ‘a mechanism-aware JIT compilation project for language-model arithmetic’. Although it is statistically impossible for an LLM to ever correctly perform any random series of arithmetic calculations, you can monitor the internal state of the model and interfere once the parameters of an arithmetic calculation have been identified. By putting the correct result back into the inference process and letting it continue you did not need to rely on external tools.

Ultimately this attempt sort-of worked, but was deemed a failure. It would seem that a language model is the wrong tool after all for replacing the humble calculator.

The Epson HX-20 is sometimes referred to as an early laptop computer. It’s a little odd in its form factor, and in its storage, relying on a microcassette drive to store data. It can be problematic to keep these tapes and drives going after so many decades, so [Andrew Menadue] has been tinkering with a more modern solution.

The replacement drive uses a Raspberry Pi Pico to emulate the original tape drive. The Pico uses a microSD card to store data instead of the magnetic media of old. The device has a small screen for showing status information and four buttons for navigation, allowing the faux drive to be controlled as to what “tape” it’s pretending to be. It’s also possible to use the device to emulate ROM cartridges that could be used with the HX-20 in place of its original tape deck storage solution.

We’ve seen some other old hardware get similar drive upgrades before, too. No surprise, because mechanical drives and media simply don’t last forever. Sometimes you need to build a replacement that’s viable today. Video after the break.

It’s never been easier to get a printed circuit board made. In fact, almost every electronics video out on the internet will incessantly remind you of this fact now. But making a custom PCB wasn’t always as straightforward as sending a KiCad file to a board house. Many DIY methods involve harsh chemicals and tedious processes, but did have the potential benefit of taking much less time than waiting on boards to arrive in the mail. [Bettina Neumryr] is demonstrating one of these older methods, called the toner transfer method, using a circuit that was printed directly in an old magazine.

The first part of the toner transfer method is to create an image that can be printed. Since this circuit came from a magazine, it is first scanned in to a computer and imported into GIMP, where it can be scaled to match the size of the components and then sharpened to make a crisp print. With the image ready, it’s time to print the image onto some toner transfer paper, ensuring that the printer in question is a laser printer which actually uses toner. From there, a sheet of blank copper PCB is prepared and then the toner is transferred by heating, in this case using a laminator. After that its etched, removing all of the copper not protected by the toner, and then the toner itself can be removed which leaves behind the copper traces.

For those of you who were around when toner transfer was in vogue, this video might not have much value. But for anyone who can’t use a board manufacturer for whatever reason or is looking for alternatives, a modern video showing the method could be much more useful and have better context for beginners than videos made a decade or more ago now. Some of those older methods include similar processes using inkjet printers instead, but there are more modern DIY methods as well using lasers or CNC machines too.

Generally the idea with photopolymers as used with resin 3D printing is that the process only works in a single direction as with all thermosets: after polymerization under influence of UV light they become an inert lump of plastic. Being able to turn these lumps back into resin would of course be ideal, as it would make recycling incredibly easy. Here depolymerizable resin turns out to be a thing, with 3Dresyn being one company that sells additives and resin which enable this (found via Fabbaloo).

These additives and resins come in essentially two flavors based on which temperature they depolymerize at, which can be at either 80°C or 150°C. This comes at a cost, of course, with the ready-to-use resin coming in at an eyewatering €833.00 for a 1 kg bottle, a factor only slightly helped by the reusability aspect.

From a more technical perspective this depolymerization feature is fascinating, as it addresses the one aspect of thermosets (like SLA and epoxy resins) that thermoplastics have as advantage, especially from a recycling view. This type of circular photopolymer appears to be quite novel, with an article by [Machado] et al. from 2024 claiming to have demonstrated the first resin that can be photopolymerized, depolymerized and subsequently again photopolymerized in a closed loop.

In the demonstration by [Machado] et al. the depolymerization is achieved using dynamic disulfide bonds, with the pulverized printed samples put into a 2-methyl-tetrahydrofuran (MeTHF) solvent. After heating at 80°C for 3 hours with an inert atmosphere, most of the photopolymerized material had returned to its original, pre-printing state. In a more recent 2025 study by [Bo Yang] et al. an approach using catalytic thermal dissociation of dithioacetal bonds was explored.

Based on the available information by 3Dresyns it would seem that their product is closer to this latter approach, with depolymerization requiring putting the part into an oven at the target temperature for up to an hour, presumably in some kind of suitable container. This is said to target elements like sacrificial molds, reusable tooling and jigs that would otherwise be discarded, or need to melt like a thermoplastic instead of acting like a thermoset. Whether a solvent like MeTHF is required as in the two cited studies is sadly unclear based on a quick scan of the site.

Thanks to [SpillsDirt] for the tip.

There are a million and one cheap OLED display modules out there. Only, the problem is, they’re all assembled on bare PCBs and they’re all slightly different, and that frustrates efforts to mount them in a clean and tidy manner. [Galopago] decided to build a small OLED module that solved this frustrating problem.

The idea to pursue this came from off-the-shelf panel displays commonly used for power supply builds and other such equipment. These come in relatively standard sizes and are designed from the outset to slot neatly into a panel with a bezel that covers any ugly edges or awkward gaps.

The build began with a 48 x 29mm enclosure grabbed from an off-the-shelf power panel meter. There are two PCBs—one holding the regulator and other equipment to run the display, the other carrying a set of screw terminals that make it easy to wire up the display to a piece of equipment. The SSD1306-copmatible OLED screen itself connects to the first board with a flat flex cable, as is the norm.

If you find yourself often wanting to pop a small display into a piece of custom test equipment, this might be relevant to your interests. Files are on Github for the curious.

We’ve featured some other fun OLED hacks over the years, like this interesting effort to whip up displays from scratch in a home lab. If you’ve got nifty usability hacks of your own in the works, don’t hesitate to let us know.

Do you have a ZKETECH EBC-A20 battery tester? Perhaps you don’t like the default software used to control the device. In that case, you might like the alternative whipped up by [Kazhuu.]

A reverse-engineering effort targeted at the EBC-A20 served as the basis for the work. The battery tester is ultimately controlled by a simple serial interface, running at 9600 bps, 8 bits, with odd parity. Armed with a relatively complete understanding of the commands used to control the device, [Kazhuu] was able to whip up a simple web app to control the device instead, using WebUSB to access the device over a USB-to-serial converter, though a desktop version for Linux and Windows is also available. If you’ve got one of these battery testers sitting on your bench, using the app is as simple as pointing your browser here with the device plugged in via USB. Then you can run basic load tests on battery cells and graph the results right on your computer without having to deal with the proprietary software.

Of course, if you don’t like the EBC-A20 battery tester, you could always build your own. If you’re whipping up your own test hardware on the lab bench, don’t hesitate to notify us on the tipsline.