Japan Launches Mission To Study Martian Moon

October 22, 2026 by No comments

Humanity has been sending robotic explorers to Mars since the 1970s, and for our efforts we’ve been rewarded with not only incredible imagery of the Red Planet’s magnificent desolation, but a wealth of information about the alien world and how it’s changed over the last several billion years. But comparatively, we know almost nothing about the planet’s two moons, Phobos and Deimos. In fact, as recently as the 1960s, there were some scientists that believed the unusual shape, mass, and orbit of Phobos hinted at the possibility that it was no moon at all, and was in actuality a derelict spacecraft of some type.

Martian Moons eXploration Spacecraft

Once the first Viking probes arrived at Mars, we had the photographic evidence and up-close measurements to prove that Phobos wasn’t artificial. But even today, we still don’t know exactly what it is. The data suggests that it’s not solid rock, and that large voids may be hiding under its surface. While we can be fairly sure there won’t be any mummified remains of Martian astronauts to be found within Phobos, vast deposits of ice are a tantalizing possibility.

With the launch of the Martian Moons eXploration (MMX) mission earlier this week, the Japan Aerospace Exploration Agency (JAXA) hopes to bring us one step closer to understanding the formation and structure of Phobos. Should everything go to plan, MMX will deploy a small rover to its tenuous surface in 2029, and by 2031, a sample return capsule will bring pieces of the mysterious moon back to Earth for further study.

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Floating-Point Addition And Subtraction On Intel’s 8087

October 22, 2026 by No comments

Although you can do basic floating point format operations like addition and subtraction just fine on any CPU, having specialized hardware for it can provide a significant speed boost. Here Intel’s 8087 was the first mainstream floating-point coprocessor to provide this option to a wide audience, with [Ken Shirriff] recently reverse-engineering using an 8087 die how these basic operations were implemented.

The real-world speed-up of even simple operations like adding two floating point numbers compared to the 8086 CPU was on the order of a hundred times, which is very relevant the moment you start doing interesting things with spreadsheets, not to mention rendering 3D scenes in CAD software or even games.

As always, the devil is in the details, with sneaky infinities and edge cases also providing the biggest potential for speed-ups in dedicated silicon, along with the large circuitry spent on the shifter. With floating point values being very much about aligning values with shifting by a number of bits, this circuitry along with the detecting of over- and underflows is the key element why the 8087 and its successors were so crucial in making floating-point operations at all feasible in PC applications.

How this shifting works in theory is detailed in the article by [Ken], along with how the 8087 implements this in its circuits. Naturally, a large part of this is implemented in microcode, the listing for which is also provided. From this it’s quite clear how what seems like a simple set of operations is actually quite complex, making even the now much maligned x87 ISA an improvement over doing it all in integer-based software.

Trying To Get Linux Running On A Nokia E6

October 22, 2026 by 15 Comments

The Nokia E6 is a smartphone from back in the old days when Symbian was a thing. [fluffleswaffled] has been doing the work to get the ancient handset running Linux instead, because that’s ultimately cooler than what the phone shipped with out of the box.

There isn’t an unlocked bootloader on the E6, so instead, [fluffleswaffled] used an altogether different route to boot Linux. A Symbian app is used to load the kernel and device tree into RAM, at which point the MMU and caches are turned off and the device jumps into Linux. It’s a one-way trip, from which there is no way back to Symbian without a power cycle. The setup nets a terminal on the phone’s own screen, and the hardware keyboard and touchscreen are functional. The display is controlled by a Broadcom VideoCore III, with [fluffleswaffled] capturing messages from Nokia’s original display driver to create a custom kernel driver that replays them.

There’s an issue, though. The phone doesn’t stay in Linux land for long — it always resets within a couple minutes of booting into the alternative OS. [fluffleswaffled] believes this is because the phone’s baseband chip is supervising the application processor, and killing things once it’s detected that the Symbian mobile stack has stopped running. They’re hoping that someone with experience with Nokia basebands or the relevant hardware can point them in the right direction to get this hack running for more than 3.5 minutes at a time.

There probably isn’t a great deal of utility in getting Linux running on a 2011 smartphone, but we love the hustle nonetheless. We’ve seen this done before, though, and it’s always interesting to learn what it takes to get the OS booting on a new platform. If you’re whipping up similar hacks in your home lab, don’t hesitate to let us know on the tipsline.

A person with blonde hair and light skin in a black t-shirt points at an image of a large QR code with what appear to be pictographic humans dancing in place of the usual blocky squares between the finding squares.

Reading QR Codes By Hand

October 21, 2026 by 4 Comments

QR codes can be a handy way to send a link or contact details without all that tedious mucking about with typing in a link, but they aren’t very useful without a smartphone to decode them. [Noel Friedrich] wondered if there was a way to do it by hand.

If it all seems a bit daunting at first, [Friedrich]’s write-up helps you work through copying a QR code to paper and then decoding it, as long as it’s version 1-5. Slashes in the template tell you where error correction has been applied to the code and you need to flip the bit back to what it was.

[Friedrich] then goes into some more details with a practical example of how the error correction works and how to exploit the ways QR codes are generated and read to make artistic QR codes. This even works to make human readable codes (without the worksheet), although the quality of the text still makes it somewhat challenging.

This isn’t the first time we’ve featured reading QR codes without a computer, but once you learn, maybe this QR code clock will be a bit more useful!

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Making A Five-Segment Display With Platinum-Titanium Cathodes

October 21, 2026 by 9 Comments

Before the advent of effective semiconductor LEDs many display types existed to display things like numbers and other characters. The Nixie tube is a well-known one, along with VFDs and there are also lesser known ones such as Burrough’s Panaplex, which all saw plentiful use in everything from calculators to audio equipment. The design that [Witchcraft and Alchemy] made appears to lean heavily on this Panaplex design.

Rather than neon, this uses argon as the gas. The anode is formed by the indium-tin oxide layer on a piece of glass, with the cathode sputtered onto the other side in the form of first a titanium layer followed by platinum. This combination helps to prevent the latter from flaking off due to incompatibilities between the molecular matrices of the glass and platinum.

Since this is an early prototype, only five segments were sputtered onto the glass and driven with a 74141 Nixie driver IC, creating the expected purple glow in a vacuum chamber. Following this a self-contained prototype was created, but this proved to be less successful, with the prototype quickly failing to light up as expected.

For a next attempt no tape or epoxy for sealing the device will be used, but rather a gasket instead of gluing the front glass onto the device. The use of conductive vias should make the device’s vacuum more permanent, and enable those last two segments to make it a seven-segment display. The final change should be to use a Penning mixture instead of pure argon.

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Every Type Of Current Sensor Explained

October 21, 2026 by 3 Comments

Measuring electric currents is an essential element of many electrical systems, but doing so in a way that is as nonintrusive as possible is not an easy problem to solve. Due to this we got a wide variety of current sensors to choose from for any given application, with [ElectrArc240] running us through these variants in a recent video.

The fairly low-tech, cheap and quite reliable method of using a shunt resistor is first demonstrated. This sees a lot of use in fairly low-voltage and low-current applications, with for example videocards using it to limit the amount of power the GPU can use, a feature that modders will happily bypass. Here simply the voltage drop across a known resistance value is measured, from which the current can be derived.

Of course, you got higher voltage and higher current applications too, as well as direct- and alternating current, with the latter especially allowing for easy current measurements simply from the electromagnetic field, or flux. Anyone who has used a clamp meter can attest to that such contact-free current sensing works, even for DC applications.

Beyond the basic transformer type you got many variants including Hall-Effect, TMR and fluxgate sensors, as well as the fiber-optic current sensor that uses an interferometer to measure the phase-change induced by the magnetic field – the Faraday effect – to the transmitted electromagnetic radiation. These more exotic types will improve resolution, at the cost of a rapidly increasing void in your project budget.

These various sensor types and their construction are demonstrated and discussed in the video, including when you’d want to use a specific type, and what the potential gotchas are with each type. Even if for many applications a simple shunt resistor suffices, it’s a good idea to know these different types, as well as their underlying theory of operation.

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Sega Genesis Controllers On The Philips CD-i

October 21, 2026 by 6 Comments

The Philips CD-i was not popular upon its launch in 1991, and is barely acknowledged today. In the opinion of [MattKC], it had a particularly poor selection of controllers, too, and it’s often hard to find used examples anyway. To rectify this situation, he whipped up an adapter to let him use Sega Genesis controllers instead.

The benefit of the Genesis controller is that it uses DB-9 connectors that are readily available, and it’s got a simple pinout that is compatible with the Atari joystick port, too. It makes interfacing the controllers supremely easy. Converting the controllers required using a Arduino Pro Micro to read the Genesis pad and translate it into something suitable for the CD-i.

On the Sega controller side, the microcontroller just has to strobe one pin while reading the state of others to determine what all the buttons are doing. The CD-i, however, expects a serial data stream from the original Philips controllers. Thus, the microcontroller is set up to poll the Genesis controller, and then translate this into the serial commands for the CD-i. It gets a little complicated, because the CD-i wasn’t really built for game controllers, but mouse-like inputs instead. But it’s not too hard to get things working once you understand what the weird Philips console is looking for.

There aren’t really any good games on the CD-i, so this isn’t a project that the retro gaming masses will be flocking to. Still, if you have a CD-i and you want to hook up some controllers on the cheap, this might come in handy. Alternatively, you could also try the BlueRetro project.

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