Scientific staff members working on the computing machine Setun

The Setun Was A Ternary Computer From The USSR In 1958

January 3, 2026 by 47 Comments

[Codeolences] tells us about the FORBIDDEN Soviet Computer That Defied Binary Logic. The Setun, the world’s first ternary computer, was developed at Moscow State University in 1958. Its troubled and short-lived history is covered in the video. The machine itself uses “trits” (ternary digits) instead of “bits” (binary digits).

When your digits have three discrete values there are a multiplicity of ways of assigning meaning to each state, and the Setun uses a system known as balanced ternary where each digit can be either -1, 0, or 1 and otherwise uses a place-value system in the normal way.

An interesting factoid that comes up in the video is that base-3 (also known as radix-3) is the maximally efficient way to represent numbers because three is the closest integer to the natural growth constant, the base of the natural logarithm, e, which is approximately 2.718 ≈ 3.

If you’re interested to know more about ternary computing check out There Are 10 Kinds Of Computers In The World and Building The First Ternary Microprocessor.

Continue reading “The Setun Was A Ternary Computer From The USSR In 1958” →

Pickle Diodes, Asymmetric Jacobs Ladders, And Other AC Surprises

January 3, 2026 by 15 Comments

While we’re 100 years past Edison’s fear, uncertainty, and doubt campaign, the fact of the matter is that DC is a bit easier to wrap one’s head around. It’s just so honest in its directness. AC, though? It can be a little shifty, and that results in some unexpected behaviors, as seen in this video from [The Action Lab].

He starts off with a very relatable observation: have you ever noticed that when you plug in a pickle, only half of it lights up? What’s up with that? Well, it’s related to the asymmetry he sees on his Jacobs ladder that has one side grow hotter than the other. In fact, it goes back to something welders who use DC know about well: the Debye sheath.

The arc of a welder, or a Jacobs ladder, or a pickle lamp is a plasma: ions and free electrons. Whichever electrode has negative is going to repel the plasma’s electrons, resulting in a sheath of positive charge around it. This positively-charged ions in the Debye sheath are going to accelerate into the anode, and voila! Heating. That’s why it matters which way the current goes when you’re welding.

With DC, that makes sense. In AC, well — one side starts as negatively charged, and that’s all it takes. It heats preferentially by creating a temporary Debye sheath. The hotter electrode is going to preferentially give off electrons compared to its colder twin — which amplifies the effect every time it swings back to negative. It seems like there’s no way to get a pure AC waveform across a plasma; there’s a positive feedback loop at whatever electrode starts negative that wants to introduce a DC bias. That’s most dramatically demonstrated with a pickle: it lights up on the preferentially heated side, showing the DC bias. Technically, that makes the infamous electric pickle a diode. We suspect the same thing would happen in a hot dog, which gives us the idea for the tastiest bridge rectifier. Nobody tell OSHA.

[The Action Lab] explains in more detail in his video, and demonstrates with ring-shaped electrode how geometry can introduce its own bias. For those of us who spend most of our time slinging solder in low-voltage DC applications, this sort of thing is fascinating.  It might be old hat to others here; if the science of a plain Jacobs ladder no longer excites you, maybe you’d find it more electrifying built into a blade.

Continue reading “Pickle Diodes, Asymmetric Jacobs Ladders, And Other AC Surprises” →

A bed of metal powder is visible through a green-tinted window. A fused metal pattern, roughly square, is visible, with one corner glowing white and throwing up sparks.

Printing In Metal With DIY SLM

January 3, 2026 by 5 Comments

An accessible 3D printer for metals has been the holy grail of amateur printer builders since at least the beginning of the RepRap project, but as tends to be the case with holy grails, it’s proven stubbornly elusive. If you have the resources to build it, though, it’s possible to replicate the professional approach with a selective laser melting (SLM) printer, such as the one [Travis Mitchell] built (this is a playlist of nine videos, but if you want to see the final results, the last video is embedded below).

Most of the playlist shows the process of physically constructing the machine, with only the last two videos getting into testing. The heart of the printer is a 500 Watt fiber laser and a galvo scan head, which account for most of the cost of the final machine. The print chamber has to be purged of oxygen with shielding gas, so [Travis] minimized the volume to reduce the amount of argon needed. The scan head therefore isn’t located in the chamber, but shines down into it through a window in the chamber’s roof. A set of repurposed industrial servo motors raises and lowers the two pistons which form the build plate and powder dispenser, and another servo drives the recoater blade which smooths on another layer of metal powder after each layer.

As with any 3D printer, getting good first-layer adhesion proved troublesome, since too much power caused the powder to melt and clump together, and too little could result in incomplete fusion. Making sure the laser was in focus improved things significantly, though heat management and consequent warping remained a challenge. The recoater blade was originally made out of printed plastic, with a silicone cord along the edge. Scraping along hot fused metal in the early tests damaged it, so [Travis] replaced it with a stainless steel blade, which gave much more consistent performance. The final results looked extremely promising, though [Travis] notes that there is still room for redesign and improvement.

This printer joins the very few other DIY SLM machines we’ve seen, though there is an amazingly broad range of other creative ideas for homemade metal printers, from electrochemical printers to those that use precise powder placement.

Continue reading “Printing In Metal With DIY SLM” →

Zork Running On 4-Bit Intel Computer

January 3, 2026 by 7 Comments

Before DOOM would run on any computing system ever produced, and indeed before it even ran on its first computer, the game that would run on any computer of the pre-DOOM era was Zork. This was a text-based adventure game first published in the late 70s that could run on a number of platforms thanks to a virtual machine that interpreted the game code. This let the programmers write a new VM for each platform rather than porting the game every time. [smbakeryt] wanted to see how far he could push this design and got the classic game running on one of the oldest computers ever produced.

The computer in question is the ubiquitous Intel 4004 processor, the first commercially available general-purpose microprocessor produced. This was a four-bit machine and predates the release of Zork by about eight years. As discussed earlier, though, the only thing needed to get Zork to run on any machine is the Z-machine for that platform, so [smbakeryt] got to work. He’s working on a Heathkit H9 terminal, and the main limitation here is the amount of RAM needed to run the game. He was able to extended the address bus to increase the available memory in hardware, but getting the Z-machine running in software took some effort as well. There’s a number of layers of software abstraction here that’s a bit surprising for 70s-era computing but which make it an extremely interesting challenge and project.

As far as [smbakeryt]’s goal of finding the “least amount of computer” that would play Zork, we’d have a hard time thinking of anything predating the 4004 that would have any reasonable user experience, but we’d always encourage others to challenge this thought and [smbakeryt]’s milestone. Similarly, DOOM has a history of running on machines far below the original recommended minimum system requirements, and one of our favorites was getting it to run on the NES.

Continue reading “Zork Running On 4-Bit Intel Computer” →

Benchmarking Windows Against Itself, From Windows XP To Windows 11

January 2, 2026 by 94 Comments

Despite faster CPUs, RAM and storage, today’s Windows experience doesn’t feel noticeably different from back in the 2000s when XP and later Windows 7 ruled the roost. To quantify this feeling, [TrigrZolt] decided to run a series of benchmarks on a range of Windows versions.

Covering Windows XP, Vista, 7, 8.1, 10 and 11, the Pro version of each with the latest service packs and updates was installed on the same laptop: a Lenovo ThinkPad X220. It features an Intel i5 2520M CPU, 8 GB of RAM, built-in Intel HD Graphics 3000 and a 256 GB HDD.

For start-up, Windows 8.1 won the race, probably due to having the Fast Boot feature, while Windows 11 came in dead last as it showed the desktop, but struggled to show the task bar. Windows XP’s install size was the smallest and also had the lowest RAM usage with nothing loaded at 800 MB versus 3.3 GB for Windows 11 in last place.

Continue reading “Benchmarking Windows Against Itself, From Windows XP To Windows 11” →

A Steam Machine Clone For An Indeterminate But Possibly Low Cost

January 2, 2026 by 28 Comments

For various reasons, crypto mining has fallen to the wayside in recent years. Partially because it was never useful other than as a speculative investment and partially because other speculative investments have been more popular lately, there are all kinds of old mining hardware available at bargain prices. One of those is the Asrock AMD BC250, which is essentially a cut down Playstation 5 but which has almost everything built into it that a gaming PC would need to run Steam, and [ETA PRIME] shows us how to get this system set up.

The first steps are to provide the computer with power, an SSD, and a fan for cooling. It’s meant to be in a server rack so this part at least is pretty straightforward. After getting it powered up there are a few changes to make in the BIOS, mostly related to memory management. [ETA PRIME] is uzing Bazzite as an operating system which helps to get games up and running easily. It plays modern games and even AAA titles at respectable resolutions and framerates almost out-of-the-box, which perhaps shouldn’t be surprising since this APU has a six-core Zen 2 processor with a fairly powerful RDNA2 graphics card, all on one board.

It’s worth noting that this build is a few weeks old now, and the video has gotten popular enough that the BC250 cards that [ETA PRIME] was able to find for $100 are reported to be much more expensive now. Still, though, even at double or triple the price this might still be an attractive price point for a self-contained, fun, small computer that lets you game relatively easily and resembles the Steam Machine in concept. There are plenty of other builds based on old mining hardware as well, so don’t limit yourself to this one popular piece of hardware. This old mining rig, for example, made an excellent media server.

Continue reading “A Steam Machine Clone For An Indeterminate But Possibly Low Cost” →

Qron0b: A Minimalist, Low-Power BCD Wristwatch

January 2, 2026 by 19 Comments

Over the decades we have seen many DIY clocks and wrist watches presented, but few are as likely to get you either drawing in the crowds, or quietly snickered at behind your back, as a binary watch of some description does. A wrist watch like [qewer]’s qron0b project which also uses BCD encoding to display the current time is among our more rare project types here, with us having to go all the way back to 2018 for a similar project as well as a BCD desk clock.

As is typical, a single CR2032 coin cell powers the entire PCB, with an ATtiny24A or compatible as the MCU, a DS1302 RTC and the requisite 4×4 LED matrix to display the hours and minutes. Technically three LEDs are unneeded here, but it looks nicely symmetrical this way, and the extra LEDs can be used for other tasks as the firmware is expanded from the current setting and reading of the time.

The AVR C firmware can be found in the above linked GitHub repository, along with the KiCad PCB project and FreeCAD design files for the watch body. The body accepts a 22 mm GT2/GT3-style watch strap to complete the assembly. With a single CR2032 you’re assured of at least a few months of runtime.