Iz in ur Tenda AC10V6, hax0ring your printf output. (Credit: Low Level, YouTube)

Hacking A Tenda AC1200 Wi-Fi Router With A CVE Combo

August 5, 2026 by Maya Posch 13 Comments

It’s rather awkward when you buy a piece of hardware like a sketchy router to make a video about its hidden admin password backdoor – known as CVE-2026-11405 – only to discover that you bought the wrong Tenda router, namely the AC10V6 model. After making this mistake, [Low Level] did the only reasonable thing one ought to do in this case, and try to find an exploit in this ‘wrong’ router as well.

The obvious start here is to do the same as with the other exploit, in that you download a firmware image from the manufacturer’s website, then pluck it apart using binwalk to do an initial check for juicy files. After that tools like Ghidra can be used to do a more in-depth analysis of any binary files, with a special focus on things like user-facing elements like login screen, as input validation will likely forever remain the number one type of exploited CVE.

One major change that Tenda made here was to encrypt the firmware image, which seemed suspicious. With that easy path blocked, the research of others on different Tenda routers was looked at, including the AC20 with the fascinating Telnet exploit in the form of CVE-2025-9090 where merely poking a file on the device turned on the Telnet service. This left the minor issue of finding a password to log into said Telnet session.

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Full Teardown Of A 2026 Amazon Fire Stick HD

August 5, 2026 by Maya Posch 17 Comments

Die of the Amazon Fire Stick HD (2026) PMIC IC. (Credit: electronupdate, YouTube)

After the release of Google’s Chromecast so-called ‘streaming sticks’ have remained a popular form factor, even though such technology is these days part of ‘smart’ TVs. Being curious as to what kind of hardware they put into these sticks or dongles these days, [electronupdate] decided to do his typical full teardown of a 2026 model Fire Stick HD from Amazon, including the typical nekkid die shots.

Although most of the bits inside are fairly typical, being just your typical Mediatek-sourced solution, the ceramic patch antennas for Bluetooth and Wi-Fi are a rather interesting detail, as are the purported limitations that make this the ‘HD’ version of the Fire Stick, unlike its 4K brethren.

The used Mediatek MT8698D SoC isn’t so different from the SoC in those 4K versions, with the 2025-era 4K Plus using the MT8696D, but the 4K Select using basically the same SoC as the HD version, featuring the same G310V2 GPU at 500 MHz per the Amazon Developer documentation and the same decoder block (VPU), both of which are capable of 4K video decoding. This implies that the HD vs 4K distinction is purely software-based.

The Amazon Fire Stick HD PCB devoid of its metal shielding. (Credit: electronupdate, YouTube)

After popping open the device and noting the various ICs, the NAND Flash, the Mediatek MT7902 wireless IC, the PMIC and the aforementioned SoC all have their caps popped in order to take a closer look at their dies. For reference, as one of the largest ICs, the SoC die is a mere 5.2 x 6.45 mm. The PMIC die is more interesting as usual, as this one integrates USB-PD functionality, adding quite a bit of logic to what is otherwise a fairly mundane bit of power management features.

Overall not a very surprising design, though it does tickle that thought in the back of one’s mind whether it could be turned into a ‘4K stick’ with a few software tweaks, or perhaps more simply by installing plain Android onto its 8 GB of eMMC.

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Train Simulator Controller: July 2026 Progress Roundup

August 5, 2026 by Maya Posch 4 Comments

For the past three years [Christopher Mitchell] has been working on his replica of a British Rail Class 800 control cab for a physical train simulator, with the July blog update providing many details on the progress.

The Class 800 series of trains is relatively new, having first entered service in the UK in 2017 on the Great Western Railway (GWR). Designed and built by Hitachi as part of their modular AT300 product series, they come in both purely electrical and diesel-electric hybrid configurations to deal with non-electrified rail sections.

British Rail Class 800 in service with LNER in 2023. (Credit: Foulger Rail Photos, Wikimedia)

Replicating the experience of driving a train is always a trade-off between what one would like and what is practical or affordable. With only a corner of his apartment to work with, [Christopher] has opted to focus on the instruments and controls in the cab, using real components where possible or building replicas for the remainder.

This entire control panel is to be used with simulators like Train Simulator and Train Sim World, using their controller APIs to both control the in-game train as well as to get feedback to be displayed on the real instruments and the various LEDs, such as those that indicate the state of the external lights. These are all controlled internally via a CAN bus, as is typical.

These instruments include genuine AWS sunflowers, part of the safety system that ensures that a driver has acknowledged a non-clear signal along the track. It’s another nice touch to a control cab simulation that’s shaping up to be rather close to the real deal.

Even if for the average person something like a Densha de Go! copy and associated controllers will likely suffice, there’s a lot to be said for having something closely resembling the real deal for a realistic game, whether it’s a train, car or airplane controller and associated instrumentation.

Polystyrene Foam Can Be Gasoline With Some Help

August 4, 2026 by Maya Posch 23 Comments

Styrofoam – or closed-cell extruded polystyrene (XPS) foam if you want to be precise – is one of those materials that is both super versatile for packaging and insulation, but also a menace when it comes to disposal, even if you ignore that the monomer styrene (C₈H₈) is a known mutagenic toxin. One of the more creative ways to deal with the metric tons of polystyrene waste generated each year is to turn it into gasoline, as demonstrated by [Lowered Expectations] in a recent video.

With polystyrene being just another hydrocarbon polymer, the idea of turning these polymers into the mixture of hydrocarbon chains we call ‘gasoline’ isn’t so crazy. The problem is mostly doing it in a way that makes some economic sense and doesn’t risk turning your domicile into a hazmat risk site or threaten the health of you, your loved ones and the neighborhood.

The method demonstrated in the video uses fairly basic methods involving pyrolysis and distillation. The first step involves dissolving the polystyrene in gasoline that was previously recovered from stale gasoline, which is another dangerously fun science experiment. This creates a thick slurry that’s then put into the distillation flask for the heating phase.

After testing the distillates for spark ignition the useful distillates were combined with fuel stabilizer added. Before tossing this into a gasoline engine tank for further testing, the concerns of auto-polymerization of styrene monomers are addressed, which requires special inhibiters.

Although this mixture runs a gasoline generator just fine, a borescope inspection of the cylinders showed a build-up of a shiny, gummy residue. There’s also the issue that this mixture contains styrene monomers, which are as noted very unhealthy to breathe in from either the fuel or any remaining monomers in the exhaust. Definitely not something to try at home, basically.

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Testing Hundreds Of Used LFP Cells Requires Some Automation

August 4, 2026 by Maya Posch 7 Comments

Although Li-ion cells have become a lot cheaper over the years, if you wish to buy hundreds of high-quality ones for that performance go-kart project, you may feel financially pressured into going for the option of stripping down years-old commercial battery packs instead.

While this is a financially sound option, you do have to figure out what the condition is of each cell before you happily stuff them into a new battery pack for said go-kart, as [Within Tolerance] recently did.

This is something that can be done manually, but for the 768 lithium iron phosphate (LFP) cells that were obtained for this project that’d be quite the tedious task. Hence it was decided to instead spend that time designing a system to automate this process, capable of charging, discharging, measuring and quantifying individual cells.

You can find the resulting Cell Goblin battery tester project on GitHub, which entails a custom PCB featuring an ESP32-S2 as the brains and associated software to monitor the process on a connected PC. Fortunately the issues on the PCB that are described in the video are claimed to be fixed in the repository version.

Using five of these dual-cell cell testers it was possible to run through the hundreds of cells with ten cells at a time. An internal resistance meter was also wired into the PC-based software via its UART. As of publication of the video the testing was still in progress, which gives some idea of how long it takes to work through those cells.

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Sketching Temporary Circuits With A Light-Triggered Floquet Topological Insulator

August 3, 2026 by Maya Posch 7 Comments

In semiconductor technology, a base material like silicon is permanently modified to induce certain electrical behavior. In comparison a topological insulator material could be used to create temporary circuits using something like light exposure. An example of this is the Floquet topological state, which has long been theorized, but is now claimed to have been demonstrated in SnTe semiconductor material, per a paper by [F. Chassot] et al. in Nature Physics.

The concept of topological insulators was first proposed in 1985, but proving their existence was hard. Recently photonic Floquet topological insulators (PFTIs) have gained interest, with experiments by [Qian Ma] et al. in 2025 as well as other teams confirming aspects of the theory.

This recent publication by [Chassot] et al. would thus confirm that optical control of topological insulators is thus possible. At the core of this effect is the band inversion that results from the light pulses, with the change in conduction being very brief, essentially for as long as the femtosecond pulses were maintained.

Although still very much in the fundamental research phase, the research on these electronic topological insulators offers an interesting look at potential new technologies, much like the field of photonic topological insulators does for photonics.

Energizing A Vacuum Tube Flip-Flop Module Of The IBM 604

August 3, 2026 by Maya Posch 10 Comments

Reverse-engineered schematic of the IBM 604's TR-3 module. (Credit: Ken Shirriff) — Reverse-engineered schematic of the IBM 604’s TR-3 module. (Credit: Ken Shirriff)

Taking a break from ogling microscopic features in Intel’s semiconductor processors, [Ken Shirriff] is back to instead poking at decidedly macroscopic pluggable modules from the 1948 IBM 604 Electronic Calculator. This time around it’s one of the so-called trigger modules in the form of the TR-3, which uses a flip-flop circuit to implement the timing signals and pulses that made the 604 work.

This differs from the thyratron module that we covered previously. A thyratron is a high current switch and rectifier, which is useful more for the periphery of the computer system. These TR-3s on the other hand were used to implement the basic logic circuits, even if a flip-flop by itself seems rather boring, being just a circuit that toggles between two states.

In this TR-3 module we find a 2033 dual triode design which thus increases density by having the two inverters of the flip-flop in the same tube. The rest of the module is taken up by the requisite capacitors and resistors that complete the circuit. After wiring up this original module, [Ken] was able to make it trigger somewhat reliably, requiring a stable input trigger.

Notable is that in the IBM 650 from 1954 this flip-flop circuit was abandoned in favor of one based on diode logic, presumably to use more reliable Boolean logic instead of the much fussier analog interactions. Naturally, in the first transistorized computers the use of diode-transistor logic (DTL) was exceedingly common, so this makes a lot of sense.

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