Building A 1:150 Scale Toyota ProBox Micro Remote Control Car

June 12, 2026 by Maya Posch 9 Comments

Although in our imagination those scale models of cars certainly can drive and steer just like their full-scale counterparts, there’s something incredibly satisfying about watching them truly come to life. Here [diorama111] is an absolute master at the craft, with the most recent conversion of a 1:150 Toyota Probox car model once again demonstrating these skills with casual ease.

We previously covered such conversions, with another recent one in 2024 involving another 1:150 scale model. That particular one demonstrated driving around on scale model roads, which shows a good practical use of this conversion if you want to have e.g. a scale model town with cars that actually drive around.

In the video you can see how first the base of the scale model has a tiny 25 mAh Li-polymer battery installed, along with two motors, one for steering and one for driving using a rod-linkage system and a lead screw.

The tiny gears used were salvaged from mechanical watches, with photoreflectors keeping track of the driving and steering positions. Remote control is done by infrared, with a tiny SMD IR receiver module in the car, while charging and programming of the MCU is done via terminals installed on the bottom.

In the final part of the video the car is demonstrated driving around, with working head- and rear lights, as well as blinkers and stop lights, including the top rear one. In the video description links are provided to the various schematics and software on Google Drive for those who are feeling like a fun Sunday afternoon project.

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Re-Enable All Compute Units On The PS5-like BC-250 Cryptomining Card

June 9, 2026 by Maya Posch 20 Comments

The custom APU at the core of Sony’s PlayStation 5 hasn’t just been quietly powering these game consoles, but also made their way onto cryptomining cards around 2023 which are called the BC-250. The APUs on these boards differ from the one found in the PS5 most notably by having two out of eight CPU cores disabled, along with many compute units (CUs) of the iGPU. Now apparently it seems that you can re-enable these CUs per instructions by [duggasco] if you’re feeling adventurous.

The BC-250's AMD APU in all its glory. (Credit: Lowest Logan, YouTube) — The BC-250’s AMD APU in all its glory. (Credit: Lowest Logan, YouTube)

As stated in the project’s README, BC-250 boards come with only 24 out of 40 CUs enabled, but this is not a permanent (e-fuse) thing. Instead you can write to two hardware registers during the GPU driver initialization, something which can be added to for example the Linux kernel module parameters.

Since many of these APUs likely had cores and CUs disabled due to them failing QA during PS5 APU manufacturing, there’s a good chance that some of the CUs truly are bad. Yet as we saw with the AMD Phenom II X3 with a supposedly bad fourth core back in the day, sometimes demand for the ‘defective’ part is high enough that good parts get mixed in as well.

Thus people like [Lowest Logan] decided to give it a shot, demonstrating the use of the patch with Bazzite Linux on a BC-250 system. After a reboot the system does indeed list 40 CUs as being enabled, and running Furmark shows a big boost in performance without any glitches or fire. There is of course thermal throttling, but that is due to the default cooling solution not being designed for running it at full blast.

Incidentally the real PS5 has only 36 active CUs, so this technically makes these unlocked APUs more powerful. With the water cooling solution demonstrated by [Lowest Logan] the thermal throttling is also resolved, showing that you can get a pretty nice gaming system out of these old cryptomining boards if you happen to win the silicon lottery.

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The Winners Of The 2025 Obfuscated C Code Contest

June 9, 2026 by Maya Posch 12 Comments

One of the most exciting challenges available to any software developer is that of writing brilliantly working code that’s so obtuse, so indecipherable, and opaque, that even its own author would struggle to grasp its inner workings after returning to it a year later. While for some this is just how they naturally write code, for others it’s part of the International Obfuscated C Coding Challenge (IOCCC), with 2025’s entrants once again showing their mettle.

The IOCCC judges entries among a range of categories, as it can be hard to otherwise quantify what is the ‘best’ entry, with ground rules limiting what the entry can entail. Generally as long as your code adheres to the C11 standard with a source size of 4,993 bytes or less and final binary size of under 2,503, is accompanied by a GNU-style Makefile and doesn’t turn a judge’s computer into a raging inferno — it should qualify.

Among the winning entries we got fun ones like ‘Most likely to shock’ by [Yusuke Endoh] which generates a Lichtenberg figure in ASCII in the terminal. There are also quite practical ones, such as the ‘Best real emulator’ winner by [Nick Craig-Wood], whose entry is a functional Game Boy emulator. Although not full-featured, it can play a range of real GB ROMs, just do not expect to get any sounds or fancy terminal-based graphics.

Repairing A Apple PowerBook 150 With Serious Issues

June 7, 2026 by Maya Posch 2 Comments

Sometimes you purchase an old device that is very cheap for a good reason. So too with the 1995 Apple PowerBook 150 that [Hugh Jeffreys] purchased for a single Aussie buck back in 2018. After finally taking it off the shelf recently, the issues are very apparent. Without even trying to turn it on, the visible damage ranges from the display that’s gone full vinegar with wolverine scratches, to the snapped hinge. Naturally the HDD also turned out to be dead.

Without a functioning display there was little point in continuing, so the disassembly started there, revealing many broken plastic clips. The cause of the vinegar symptom is the degrading polarizer, which with some finesse can be removed like a thick screen protector. Fortunately, here it’s put on top of the glass layer of the display, so after peeling it off the remaining glue can be safely dissolved and scraped away.

Inside the case the RTC battery was found to have started leaking, causing corrosion and damaging a variety of important traces for the keyboard and display. All of this damage seemed fixable, but after a while the damage was just too severe. Fortunately he was able to obtain a replacement for the affected daughter PCB, which allowed the display to come back to life, so that a new polarizer could be installed after cutting a large sheet down to size.

A replacement hinge was then printed in PETG and glued to the part of the lid where it had broken off, while snapped plastic clips were reinforced with glue where they had hung on. Finally, the IDE HDD was replaced with a CF card via an IDE adapter and the entire system reassembled.

Unfortunately [Hugh] wasn’t able to immediately source or create MacOS floppies with a version that the laptop wanted to install from, so that part couldn’t be tested yet, but there’s a good chance that this old PowerBook 150 has finally been cured of at least its biggest ills, without spending much more than the original asking price.

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Using Windows 11 On An LGA 775 PC With AGP Videocard

June 5, 2026 by Maya Posch 15 Comments

Although the thought of installing a modern operating system like Windows 11 on something as archaic as a Core 2 Quad Q6600 Intel CPU may seem ridiculous, it being the flagship CPU of the time means that it still chews up low-end Celeron systems that are on the supported hardware list like the N4020. Hence [Omores] commencing on this latest adventure, with the snag being that the chosen mainboard features an AGP bus that Windows 11 no longer supports.

A GPU box from the related HD 4670 PCIe card, not the used HD 4650 AGP card with 1 GB of DDR2. (Credit: Omores, YouTube) — A GPU box from the related HD 4670 PCIe card, not the used HD 4650 AGP card with 1 GB of DDR2.

This system is intended to multi-boot a range of Windows OSes starting with Windows 98, while also playing nice with DOS and even Windows 11. In addition to the quad-core, 2.4 GHz Q6600 there’s also an amazing 3 GB of DDR1 RAM in the system.

The mainboard is the 2003-era Asrock 865PE, with the GPU being the highest-end GPU that still came in AGP flavor: the Radeon HD 4650 from 2009. Since the sole reason that Windows 11 doesn’t support AGP any more is due to the supporting files not being included with Windows 11, hence you can track it down on a Windows 10 1507 release install – such as the Intel AGP440.sys driver here – and install them with some file editing.

Since Windows 11 still supports the WDDM driver model from Windows Vista and 7 you can then install the Catalyst drivers from 2012 and be up and running. You only get 1 GB of VRAM for this card, but you probably don’t need much more on this level of hardware.

One major stumbling block remains, however, as Windows 11 24H2 enforces SSE4.2 instructions which the CPU doesn’t support. Ergo 23H2 is the newest Windows 11 version that can run on this system, with only the Education and Enterprise still receiving security updates, making it a bit of a pyrrhic victory, especially as Windows 7 benchmarks a fair bit faster on the same hardware.

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Texas Instruments Changes The NE5532 And Others Into Incompatible Versions

June 3, 2026 by Maya Posch 46 Comments

First introduced in 1979 by Signetics, the NE5532 was a pretty spiffy dual op-amp for the time with low noise and low distortion. Over the years it has become a standard part that showed up in countless audio products, and has become a so-called jellybean generic component with Texas Instruments (TI) being one of countless manufacturers.

It being such a standard, multi-sourced part makes it thus even more puzzling that TI has now decided to completely overhaul this IC in a way that makes it incompatible with even the original Signetics NE5532. These changes are covered in detail by [Dave] of EEVblog as his mind is pretty much blown at such an incomprehensible change.

The changes entail an entirely different manufacturing process and a big change in specifications, while making no change to the part number. In revision K of the TI datasheet these changes are first seen, with some specifications changed for the better, like a higher unity gain bandwidth by 2 MHz, but a much slower slew rate.

Although the 5532 op-amps are multi-sourced, there are good reasons to just stick with manufacturers like TI, as that means receiving a product change notification (PCN) when anything changes. In the PCN related to this op-amp a change to process node is noted, along with other changes, but no reasoning.

Among the other big changes are a reduction in the supply voltage from 22 V to 18 V, and a halving of the ESD protection from 2 kV to 1 kV. Although it might be slightly more efficient on the new process node this way, it clearly comes with a lot of trade-offs that make it an overall worse op-amp, while also being incompatible with the same op-amp from other manufacturers.

In the video [Dave] goes through the datasheets of this jellybean part of other manufacturers, showing that they still have the original 1980s specifications. Only one exception here was the NE5532DR from Shenzhen HuaXuanYang Electronics, whose supply rail voltage is also 18 V for some reason, along with a similar internal transistor configuration that reduces the ESD resistance.

In addition to the NE5532 op-amp, it seems that TI also took an axe to the OPA134 op-amp, by removing its offset trim feature and listing the pins as ‘NC’, with a warning to not connect these pins and also worsening other specifications. This makes these similar jellybean parts incompatible, with no change to the part number. Worse is that it continues with the LMH6518, whose changes [Dave] argues might even kill oscilloscopes as they are commonly found in those.

Meanwhile the LM317M also got an overhaul, but here TI opted to give it a new part name, calling it the LM317MQ with at first glance no major degradations in the specifications, but instead some actual improvements. This makes it even more puzzling why TI didn’t give the other ICs a new part number to differentiate them from the jellybean part.

Until there’s some clarification from the side of TI, it might be a good idea to source these parts from a manufacturer that is not TI, especially when replacing these ICs in older devices.

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Spacelab’s Mitra 125 MS

May 24, 2026 by Al Williams 4 Comments

[Ken Shirriff] does some of the most interesting teardowns. This time, he’s looking at a French-built minicomputer called the Mitra 125 MS from around 1980. In particular, it was the computer inside Spacelab, a European lab that could fit in the back of the Space Shuttle.

As you might expect, the computer doesn’t contain a microprocessor. Instead, it is a series of cards and, in this post, [Ken’s] looking at the ALU that allows the computer to perform math operations.

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