Repairing A Couple Of Very Expensive Registered DDR5 RAM Sticks

October 7, 2026 by Maya Posch 42 Comments

It’s definitely a sign of the times when repair shops get handed sticks of registered ECC DDR5 RAM by businesses to try and fix, rather than just tossing the defective ones and slotting in a fresh bunch. This is how [northwestrepair] ended up with two of these ECC RDIMMs, with a current market valuation of a rather nice budget car.

The 128 GB stick was first on the bench, with the fault being that it would fail DDR5 training on boot. This suggests that one or more of the DRAM BGA packages had developed a cracked solder joint, which is something that you could conceivably fix with more diagnosing and testing for a single IC reballing.

In this case doing a reflow cycle was enough to bring the RAM back to life, with the DDR5 training now passing without issues in a test system.

For the 256 GB stick things wouldn’t be so easy, as it seemed completely dead. This suggested a dead PMIC, as this is the component on DDR5 RAM responsible for ensuring that the DRAM ICs even power on. The SPD ROM was another option, so that got swapped first, which does require reprogramming the RDIMM. For this the earlier SPD dump image was reflashed, but swapping this chip made no difference.

After some additional reflowing of a few suspect ICs, still nothing happened. Following this a lot of reballing and other troubleshooting steps followed, only for the problem to be one shorted MLCC and a broken PMIC, potentially caused by whoever dropped said RDIMM onto the server room floor.

Cracked MLCCs do appear to be a very common cause of failures, as they’re often used as filter capacitors, same as for this RDIMM. Checking for shorts across a number of such MLCCs can be a good way to shorten a diagnostic cycle. Since this RDIMM was dropped, reballing every IC probably was still a good move as this may have cracked some solder balls.

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Scientists Create Hexagonal Packed Ice At Extreme Pressures

October 6, 2026 by Maya Posch 10 Comments

One of the problems with planetary science is that you generally cannot easily investigate the exact conditions in their interior, so you’re left to extrapolate what is happening inside them based on surface scans. One of the resulting questions is what ice giants like Neptune and Uranus in Earth’s solar system have exactly at their core. We do know that it is mostly rocks and ice, but what kind of ice you end up with at these intense pressures is a good question that [Alexis Forestier] et al. set out to answer, with their results published in a Physical Review Letter paper (ArXiv preprint).

It’s noteworthy that there isn’t just water ice at these planetary cores, with this study only investigating water ice specifically. In order to get the water to the pressures it would experience courtesy of ice giant gravity, a diamond anvil was used, with synchrotron x-ray diffraction allowing for the changes to the sample to be observed.

The phase diagram of water includes a number of phases beyond what us Earth-dwellers would call ‘ice’, with at higher pressures above about 80 GPa the formation of ice X, featuring a body-centered cubic (BCC) oxygen sublattice. Subsequent discovered phases were face-centered cubic (FCC) and now hexagonal close-packed (HCP) ice, all differing in the packing of the oxygen sublattice.

In addition to extreme pressures, temperatures also had to be increased by using the laser heating feature of the diamond anvil. At around 2,000K and over 200 GPa the HCP phase was found, with a mixed FCC-HCP phase at intermediate pressures.

Although not immediately providing answers to questions pertaining to the aforementioned ice giants, it gives planetary scientists yet another clue that they can use in future investigations, as well as provide more insight into this most fascinating phase of water that’s actually its own little galaxy of phases.

The EDG C++ Compiler Frontend Has Been Open Sourced

October 6, 2026 by Maya Posch 7 Comments

Recently [John Spicer] of the EDG C++ compiler front-end project announced that the project will be made open source, from now on managed by the non-profit C++ Alliance. Related source code can be found on the GitHub account.

The Edison Design Group (EDG) is a US company which has made compiler front-ends since 1988, previously also for Java and Fortran. They are used in the Intel C++ compiler, Microsoft’s VC++, NVIDIA’s CUDA compiler, as well as many other commercial products. Last year the decision was made to shutdown the company in 2026 and transition to an open source model, with the details outlined on the EDGCPP site.

Although far from the only C++ front-end, EDGCPP will be very interesting still for supporting bleeding-edge features and having been used in such wide-ranging, demanding applications by a host of commercial customers. For most of us C++ developers our contact with it will have been via the MSVC and Intel Compiler Collection tooling, but of course it’s just one part of the entire toolset.

We’re looking forward to seeing what this means for the wider open source C++ ecosystem, especially as it pertains to GCC and LLVM’s Clang.

Using LineageOS For Phones And DIY Smart TVs Is Pretty Nifty

October 6, 2026 by Maya Posch 26 Comments

Although Android is essentially just another Linux distribution, most people only experience it in the form of the rather restrictive and proprietary versions found on smartphones, tablets and smart TVs. While this is probably fine for the average person, there’s also a lot to be said for the more pure Android experience in the form of LineageOS.

With this fully open and community-supported version of Android you’re free to muck about with your hardware to your heart’s content, without annoyances like unremovable bloatware apps and restrictions on e.g. enabling developer mode.

Even more fun is that there are ports of LineageOS to systems such as the Raspberry Pi SBC, including in the Android TV configuration. This means that not only can your ten year old Android phone get a make-over with a recent version of Android, you can also create your own Android TV-based smart TV without all the spying and other nasty things that commercial smart TVs love to do.

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3D-Printed Filter Removes Most Microplastics From Water

October 5, 2026 by Maya Posch 20 Comments

With the rise of synthetic polymers in everywhere from clothing, packaging and beyond, we have also seen a corresponding rise in fragments of these polymers in the environment. These micro- and nanoplastics (MNPs) come in a wide variety of sizes, but have in common that they do not break down very easily, leaving filtration as an important way to keep them out of our potable water sources. A recent paper by [Ethan A. Crawford] et al. in Separation and Purification Technology details a way to use a low-cost, 3D-printed filtration mesh to filter out up to 90% of MNPs using their prototype.

This prototype uses a multi-layer filtration system printed in PLA, creating a flow-through system in which polyethylene glycol (PEG) acts as a sacrificial additive to the PLA. Whereas creating the fine pores required for filtration of MNPs is impossible using FDM printing, the spheres of PEG that form inside the printed filter can be subsequently etched away using nothing but hot (80°C) water, leaving behind a porous surface capable of trapping fine particles.

These pores are characterized in the paper, with the PLA-PEG10 sample showing the best porous structure while maintaining structural integrity of the PLA material. With 20 layers of these filters a filtration efficiency of 90% was achieved, though as the authors note aspects like improving the system and potential reusability still have to be investigated.

We have previously looked at MNPs, including how little we know about how many of them really are inside our bodies right now, and how lab gloves may be contaminating test results.

How To Grow A Giant Crystal From Copper Sulfate

October 5, 2026 by Maya Posch 15 Comments

Copper sulfate crystals are probably among one of the prettiest crystals you can grow at home, with even just a simple setup with some copper scrap and vinegar already capable of producing lots of them. Yet what if you want to grow really big ones? In that case the [Crystalverse] has got your back, with a recent video that expands on an older blog post.

In lieu of the copper-and-vinegar approach you can also obtain copper sulfate directly, since it’s a common fungicide, rootkiller as well as drying agent. This means that your local brick-and-mortar retailer or favorite online store probably has a few kg of the stuff available for sale.

As with most large crystal growing procedures the key is to have a saturated solution, which for copper sulfate just takes near-boiling water, to create a mesmerizingly blue liquid if there are no contaminants in it. By adding slightly more copper sulfate there are also crystallization sites on the bottom of the jar to draw these away from your large crystal.

From there it’s the same as with growing other large crystals – even those from sugar – with a seed crystal suspended into the solution, along with a silent prayer to the crystal gods that said seed crystal continues to grow without any defects. One gotcha with copper sulfate crystals is that the intense blue color is largely due to the presence of water molecules. This means that once it dehydrates, it turns effectively white.

Also of note that is the slower the crystal grows, the better the result is likely to be. During the months that it takes for these large crystals to grow, you need to carefully manage the copper sulfate solution, remove competing crystals on the bottom of the container and keep the temperature as constant as possible.

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Porting Video Games To VHS

October 5, 2026 by Maya Posch 13 Comments

Although VHS-based games have existed for about as long as VHS players have sat in millions of living rooms, they always tended to be rather sparse gaming experiences. For example, the ActionMax gaming “console” that [Throaty Mumbo] shows off in his most recent video. You use a zapper to purportedly shoot down on-screen targets in “games” like Sonic Fury. After this disappointing experience, he figured he should probably make his own interpretation of a VHS-based video game.

This involves a DE1-SoC FPGA board along with an RP2350 MCU. There’s also an in-progress GitHub repository for those who wish to follow along. Rather than the simplistic Action Max system that plays exactly the same every time along with a basic light gun feature, this actually allows for interactive gameplay.

The video shows that the VHS tape contains both binary data for the game, as well as a number of video streams. This is decoded using the DE1’s composite input, with the RP2350 then acting on the decoded game data and handling input from the controller. With this, interesting effects can be accomplished, such as background video streams for the original Super Mario Bros.

Other demos include Night Trap and a variant of Doom that uses prerecorded video segments along with action events requiring you to press a specific button. Since there’s actual bytecode involved, quite a few more options are available for game development that could have been interesting to a 1980s audience.

It is hard to imagine how hard it was to get the VCR into homes, only for it to vanish again.

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