Three Arduinos Team Up To Make 80s-Style Computer

May 27, 2026 by 22 Comments

Back in the 80s, buying a home computer could easily mean an inflation-adjusted cost of thousands of dollars (or your equivalent currency unit of choice), and all for an 8-bit machine that might not have a hard drive and almost certainly didn’t connect to a network. Here in the future it’s easy to get spoiled by all the computing power and inexpensive devices practically falling into our laps, but using some modern low-cost microcontrollers can connect us to our early computing roots like [Joe]’s latest Arduino-based computer.

Taking design an engineering cues from computers like the Timex Sinclair 1000, Commodore PET, and TRS-80 MC-10, this computer uses a trio of Arduinos to accomplish what the best computer manufacturers once did with tons of integrated circuits. An Arduino Due handles all of the processing and traditional computing tasks, including a somewhat customized BASIC implementation, while an Uno performs audio processing duties. Taking care of the video processing is the much more capable Arduino Mega, outputting 40×25 monochrome NTSC composite video at 8×8 character resolution. There’s even WiFi courtesy of an ESP32 — certainly an upgrade compared to the source material.

After booting it up, the user gets a Commodore-like experience that replicates the 80s computing era quite well, and is even built inside its own keyboard case just like that era of computers usually were. [Joe] plans to release all three firmware images and the Python script used to get files onto the faux-retro machine, so keep an eye out for that.

In the event that you used rubles instead of dollars to pay for your expensive 8-bit machines back in the 80s, this computer might be more up your alley instead.

Hunting Submarines Via Gravity Is A Tough Errand

May 27, 2026 by 45 Comments

Among so many other technological advances, the Cold War saw the advent of the ballistic missile submarine. The concept was simple—pack enough nuclear warheads to destroy a small civilization into a compact metal tube, and then hide it underwater. The oceans would act as a cloak for your fleet of world-enders, and keep your enemies forever on their toes. A terrifying machine that could both start and end a war with the push of a button.

Most nation states are populated by humans with the will to live. Thus, there has been a great incentive to find ways to keep tabs on these sunken doombringers. Great efforts have gone into improving sonar and magnetic detection methods over the decades, which are the bread and butter of sub hunting to this day. However, military researchers have also explored the prospect of whether submarines could be detected via their effect on the gravitational field alone.

Continue reading “Hunting Submarines Via Gravity Is A Tough Errand” →

So Long, CHU, And Thanks For All The Time Signals

May 27, 2026 by 52 Comments

In the long ago, pre-internet days when your clock project wasn’t an ESP32 getting its timing via NTP over WiFi, it was still possible to build a wirelessly-updating clock. All you needed was a shortwave receiver tuned to a time signal — perhaps like the National Research Council of Canada’s CHU, found on the dial at 3330, 7850, and 14 670 kHz. At least, it can be found at those frequencies until June 22nd, 2026, when the station will finally go dark.

Depending where you were on Earth, it might have been easier to tune into CHU than the United States based WWVB, or one of the various European signals like DCF77 or the UK’s MSF. If you’re not into radio, all these time signals have essentially the same job, if you hadn’t guessed: tell the time. This can be done in a variety of ways, and CHU has made use of more than one of them since its establishment in 1923.

Initially, the time was sent in Morse code, but later they added a speaking clock for easier human listening in both Canadian French and English. For synchronizing radio clocks, a series of pulses is given in DUT1 format using 0.3s pulses — which is what older clocks would have been listening to — and nowadays a digital FSK time code for more modern equipment. You can have a listen through the video by [Shortwave Listener] embedded below.

It’s not our place to judge the Government of Canada for trying to save money where they can. It wasn’t so long ago that WWVB was in danger of shutting down for similar reasons. But we’re still going to miss those beeps. If you do tune in before the station goes dark, CHU should still be giving out QSL cards. Get yours before it’s gone forever.

If you do have a clock that relies on this time signal, don’t worry. You can make your own, perhaps with a GPS time source.

Continue reading “So Long, CHU, And Thanks For All The Time Signals” →

See Aerodynamics In Action With A Desktop Wind Tunnel

May 27, 2026 by 9 Comments

While most of us don’t design aircraft or racing cars, it’s likely that we’re still fascinated by some of the aerodynamic studies behind them. But a full-sized wind tunnel is going to cost a small fortune, so how can we experiment? Never fear, because [luisengineering] is here with a 3D printable desktop wind tunnel.

There’s a build video that we’ve embedded below, and if you can sit through the continuous shilling of random tools, it’s an interesting watch. It’s an open design in that air is not recirculate through it, instead it passed through the machine from left to right. On the right is the fan, on the left the intake with a rectifier to ensure laminar flow. Then a constriction compresses and speeds up the air past the stage for the model under test, and an expansion slows it down again for the fan.

A wind tunnel needs a smoke generator to easily spot turbulence, and in this case a vape is called into action. The result is surprisingly effective, as we see with a demonstration using a small model car. Meanwhile if you’re interested in wind tunnels at this size, it’s not the first one we’ve brought you.

Continue reading “See Aerodynamics In Action With A Desktop Wind Tunnel” →

A Bicycle Built On An Italian Renaissance Tech Base

May 26, 2026 by 24 Comments

There is a drawing of a bicycle in one of Leonarda DaVinci‘s sketchbooks– except it wasn’t drawn by DaVinci, and dates long after his death, so we can’t say the old master invented the bicycle. We can, however, wonder what it would have looked like if he did– and so did the [How To Make Everything] YouTube channel. As you might expect, they investigated the question of a Renaissance Bicycle in the best possible way: they built one.

In some ways the device looks like the first, primitive hobby-horse proto-bicycle of the early 19th century, which is not without reason. From the renaissance to the dawn of the industrial era, there wasn’t a huge change in how europeans worked with wood, and in both eras wood is the obvious choice. Where this bike differs from [Karl Drais]’s invention is that it has both pedals and brakes– both of them using drawings from DaVinci’s sketchbook.

You might be surprised to learn that ball-bearings are period-appropriate, and weren’t even invented by DaVinci. The drum brake, on the other hand, is right out of the Old Master’s notes: a steel band wraps around a drum on the rear break, and is tighened by a lever. With iron rims, no brake would stop on a dime, and this probably works as well as anything while being quite simple to make.

The chain is also based on one in DaVinci’s notes, and honesty it’s a weak point of the design; they’d likely have been better off with a leather belt, or perhaps a stack of gears as we’ve seen before. The hand-made chain just isn’t able to get the bike up to riding speed. Still, this is recognizably a bicycle and entertaining content for anyone who plans on violating the temporal prime directive or wants to get around after the apocalypse.

Continue reading “A Bicycle Built On An Italian Renaissance Tech Base” →

A phone running the XFCE desktop environment is placed on a desk, with a wireless keyboard in front of it.

Linux On Android Provides Inexpensive, Powerful Computing

May 26, 2026 by 49 Comments

In some parts of the world it’s common for cell service providers to sell new phones at a price significantly below market value, with the caveat that these phones are locked to that service provider alone. It’s questionable whether this practice is good for consumers, but as [Gabriel Broussard Korr] notes, it’s an opportunity for hackers: since it’s possible to run a Linux environment on these phones, they make an inexpensive source of quite powerful computing hardware.

In this case, [Gabriel] was using the Moto G Power 2024, which has 128 GB of storage, 12 GB of RAM, and costs less than $50 when carrier-locked. Rather than trying to install a mobile-oriented Linux distribution (such as postmarketOS), [Gabriel] installed Termux, a terminal emulator which provides a Linux environment within Android. Before doing this, he set up the phone and configured a number of settings for a better Linux experience. Since automatic updates can interfere with these settings, and since none of the provided settings effectively disable these, he used NetGuard to block Internet access from the updater app and from Google Play services.

The next step was to actually install Termux, as well as an X11 extension and an app which exposes an API for Termux. The desktop environment (XFCE in this case) was installed through Termux, and [Gabriel] wrote a shell script to go through the steps of starting it. XFCE worked well on mobile devices because of its full-desktop zoom capability. Even running Linux indirectly, the experience was smooth; [Gabriel] found that GIMP, Shotcut, and VS Code all performed well.

It’s not quite the same set of software, but we’ve previously featured a guide to setting up a similar Linux environment using Termux and AnLinux. Lindroid provides a similar containerized Linux environment; on the other hand, you can also use postmarketOS to make a server from an old phone.

Drawing Videos On An Etch-a-Sketch

May 26, 2026 by 2 Comments

We’ve covered etch-a-sketch robots before, but usually they’re not quite as fast as [Every Flavor of Robot]’s “video” etch-a-sketch, capable of drawing a full portrait in as little as a minute.

The robot, nearly finished drawing a portrait of [William Osman]
The idea comes from the motivation to make something cool for Open Sauce. Of course, most projects with a deadline come very close to missing it, and–like many an Open Sauce project–this one is no exception. Arriving in California, they realize they couldn’t access their code! Fortunately, they get a demo working where your portrait is drawn just in time.
Continue reading “Drawing Videos On An Etch-a-Sketch” →