Running DOOM On A Cheap 104-in-One Handheld

August 11, 2026 by Maya Posch 9 Comments

Taking a break from putting DOOM on devices that absolutely were never conceived for use as gaming devices, [Aaron Christophel] recently got enticed by some cheapo handheld gaming systems at his local Action budget store. One is a controller-shaped ‘mini game console’ with 104 games from the 1980s and 1990s, while the other is simply a Pac-Man handheld in a more typical rectangular form factor. Although this brings to mind basic blob chips and limited hacking potential, as it turns out they’re actually quite nice inside.

As also covered in the demonstration video, rather than said nasty blob chip, both handhelds turned out to use the same unmarked MCU in QFN48 packaging. Some prodding and poking confirmed that it’s a typical ARM core, specifically a Cortex-M33 compatible STAR-MC1 ARMv8-M from an unknown manufacturer. Without a datasheet to go by, its limitations had to be discovered experimentally.

Of those, the biggest were a clock speed of 62 MHz – instead of the typical 194 MHz – as well as a lack of sound. This latter issue might be fixable with a better understanding of what appears to be a quirky DMA-fed DAC. Beyond this you’re also dealing with limited memory and of course just 4 MB of flash, though the chip for this might be upgradable if the MCU can map more. You do get a 320×240 display and a lot of buttons, which is admittedly nice.

As for the price difference of around $8/€7 for the Pac-Man version, this appears to be due to it running an officially licensed Bandai Namco arcade emulator as firmware, while the 104-in-one unit runs FlyThings/ZKSWE with a NES emulator.

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Teardown Of An Oxford Nanopore MinION DNA Sequencer

August 10, 2026 by Maya Posch 9 Comments

Detail of the nanopore chip. (Credit: mikeselectricstuff, YouTube)

For most people the term ‘DNA sequencing’ probably brings to mind large, expensive laboratory equipment in sterile rooms, but over the past decades technological progress really has had its way with it, to the point where it’s now just another small portable device. Something like the Oxford Nanopore MinION unit that [Mike] recently took to bits to ogle at the intricate insides.

This device was trialed in 2014 in a limited release before its commercial release in 2015, with this paper by [Miten Jain] et al. in Genome Biology detailing the workings of this nanopore sequencer. At a mere $2,000 it’s rather remarkable how affordable it is, though this comes with the caveat of the consumables, which are also shown in the video. These come in at a cool £690 per unit, can sequence either RNA or DNA and can be used at most a few times before they need to be replaced.

The main unit is fairly simple, featuring a Xilinx Spartan 6 FPGA and a rather nice slim fan-based cooling solution. For the nanopore unit you get the typical microfluidics system, to guide the deposited fluid containing the genetic material to sequence over the nanopore system. In here we see the actual magic as well, in the form of the high-density pitch ICs on both sides of the PCB inside the consumable sequencer unit.

Although this particular unit got discontinued already, the consumables are still available for it if you are feeling the sequencing itch. Of course, we’re likely to see the costs for DNA and RNA sequencing to keep plummeting, as what were once complex chips get overtaken once again by the progress of technology.

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The Physics Of Keeping Thermal Power Stations Cool

August 10, 2026 by Maya Posch 8 Comments

Recently thermal power stations have been in the news quite a bit, mostly in the context of them being throttled back or shut down due to the river water used to cool them either getting too warm or said river having dropped to a level where it can no longer provide cooling water. Obviously this is a problem, but it helps to understand how we got to this point and what can be done to fix it.

Thermal power stations – also called power plants – come in a wide variety of shapes and sizes, ranging from old-school coal- and gas-fueled power stations to modern nuclear power plants. Something like a concentrated solar power (CSP) station is also a thermal power station, as all of them have a heat source that’s used to generate electricity from, whether that’s a boiler, nuclear reactor core or a big vat of sodium heated up by the Sun via massive mirrors or oil-filled tubes in parabolic throughs.

Except for open-cycle gas turbines (OCGTs) – which are basically jet engines connected to a generator – this thermal energy is then used to generate steam that drives a steam turbine. Once most energy in the steam has been depleted, it has to be condensed back into e.g. water, so that it can be led back to the steam generator. How this condensing step is performed is the question here, with a number of methods available.

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Creating A Supersonic Trebuchet

August 9, 2026 by Maya Posch 27 Comments

As awesome as trebuchets are, the fact that medieval engineers didn’t create versions capable of launching supersonic projectiles is a bit of a bummer. Fortunately it’s possible to correct this oversight with modern insights and technologies, as [Tom Stanton] demonstrates in a recent video.

While a traditional trebuchet is fairly straightforward, using a heavy weight moving an arm around a pivot that has the projectile attached to the other side, a few tweaks can make it much more lethal. One change is to have the projectile’s rope wound around the arm, forcing an additional pass around the arm to gain velocity. The other is to use a gearing system which uses the dropping weight’s energy more efficiently.

One complication here is that the arm now takes a few rotations to come up to speed, meaning that the release of the payload has to be controlled exactly, with only about an 0.0025 second release window. The solution was both low-tech and effective: since the arm is attached to a drum that the rope is wound onto, the moment enough rope is unwound from the dropping weight, a latch inside the drum is released to launch the projectile.

In a first test with a 10 kg weight, the projectile reached a velocity of around 528 km/h, which definitely was a good start, but also showed just how not aerodynamic the arm was. Some redesigns later of the entire trebuchet, the entire system was tested again with 10 kg and achieved a projectile velocity of 634 km/h. From there it was time to ramp up the weight to the full 40 kg, which theoretically should hit supersonic speeds.

Unfortunately the first attempt hit a mere 1,152 km/h (716 mph), which is just shy of the sound barrier at 1,235 km/h at 39% system efficiency and some components clearly breaking apart. Some more redesigns later and with a lighter projectile at 4 grams, a 40 kg weight achieved an arm speed of 2,342 rpm. The projectile now left the sling with 346.4 m/s, or 1,249 km/h, with an audible snap as the sound barrier got broken.

Even if the era of trebuchets in warfare is well and truly past, they remain fascinating physics demonstrations, with this case in point.

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The Stages Of Grief In Repairing A Trinitron Found In The Trash

August 9, 2026 by Maya Posch 28 Comments

Sometimes you see a project just staring at you with proverbial puppy dog eyes and you just cannot look away. In the case of a once rather nice Sony TV it was the smooth 32″ Trinitron CRT that gave [Happychoice] that look when he came across it along the side of the road. Naturally he had to beg the owner of the junkyard to please let him adopt the pupp^Wjunked TV and attempted an ill-advised repair.

Some later sleuthing revealed that this poor TV had been sitting on the side of that road for at least six years, exposed to the worst that the Italian weather and local fauna could do to it, so it was no surprise that all he got out of it even after cleaning and some repairs was a sad triple-blink of the power LED. This indicated that something on the control board was very unhappy about the status of the power supply.

Over the course of a few months this project went correspondingly from careful optimism down to the depths of depression, through the fields of bargaining and into the blue skies of acceptance of a likely far more involved repair session than originally assumed. That said, the CRT itself looks to be in pretty good nick, as do the PCBs barring the few sketchy resistors that already got replaced.

We would like to congratulate [Happychoice] on the acquisition of a fun new repair project and wish him all the luck on bringing this beast of a TV back to life.

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The Chinese Smart Glasses Proving That Smart Glasses Can Be Repairable

August 9, 2026 by Maya Posch 21 Comments

It’s often claimed that wearable devices cannot have user-replaceable batteries or even be serviceable at all due to how compact and waterproof they must be, yet there are plenty of examples belying those claims. So too for smart glasses with their compact size and the need to be fully waterproof. They would be certified e-waste as soon as the built-in battery stops being a battery, assuming these claims were true. Recently [iFixit] bought a few Chinese smart glasses to see just how repairable they are, with the Rokid one being very surprising.

The first nice feature of both two Chinese smart glasses is that they have an external battery that clips on in addition to an internal one. Internally they’re quite similar, both featuring a Qualcomm Snapdragon AR1 Gen 1 SoC with 32 GB of eMMC storage, in addition to micro-LED projectors.

Of the two glasses in the video, the Quark one isn’t that dissimilar from the Ray-Ban and Meta ones, requiring fairly destructive heat and prying to get inside. The Rokid one is however very easy to get into, with very light glue that makes it easy to get into, as well as a very servicing-friendly internal architecture including its battery. This is a pattern that extends to its external battery module, giving a glimpse at what such devices ought to look like in a repair-friendly world.

As is to be expected for an [iFixit] video, a significant part of it is spent lamenting the ills of glued-in batteries, including the recent decision by the EU to exempt many wearable devices from its new right to repair regulations involving built-in batteries. In light of the teardown of the Rokid smart glasses in this video, as well as previous Pixel Watch 4 and Fairbuds teardowns, it certainly seems reasonable to enforce user-replaceable batteries for these wearables as well.

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High-Density Parchment Paper Papertronics With Laser-Carved Hydrophilic Channels

August 8, 2026 by Maya Posch 6 Comments

Paper as a substrate for electronic circuits is not very common, but promising for flexible circuits with low cost and easy recyclability. That said, paper is not an easy material to work with when printing traces, as the cellulose material is both absorbent and irregular, limiting the resolution and accuracy of so-called papertronics. Even when using higher-quality paper with wax-based masks this resulted in poor resolution issues, so [Zahra Rafiee] et al. opted to approach the problem from the other direction, by using hydrophobic parchment paper as the base combined with a laser.

The nice thing about the inks used with papertronics that they aren’t just traces, but can also be functional elements like resistors, which is also demonstrated in the paper. The channels for the inks are created using a 50 Watt CO₂ laser, which etches away the silicone coating on the parchment paper. The achieved resolution in the article is around 250 µm for line widths and 300 µm line spacing, which is much better than that for wax-based alternatives.

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