Power From Gravity

May 26, 2026 by 1 Comment

Gravity batteries aren’t exactly a new idea. You can store energy by lifting something heavy, converting kinetic energy into potential energy. To get it back, you let the mass fall and convert that motion to electricity. [Valeriamayara22] shows how to build a working demonstration model of such a system.

This isn’t free energy. Something has to lift the weight. In this case, the height is 1.8 meters, and the mass is 15.65 kg. Even so, the model achieves 13 W peak output and 58% efficiency, according to the post. Reportedly, it takes 394 drops of the weight to fully charge an iPhone 16, so this isn’t a practical project, but it does show how a gravity battery works. One nice thing is that the system stores as much energy on its 1,000,000 th charge as it does on the first one, especially if you keep the chain lubricated. Try that with a chemical battery.

The mechanical part uses a bicycle chain and some sprockets. There is a battery to even things out since, like wind power, when you make energy with a mechanical battery, you either use it now or lose it.

The cost of the build is about $400, and there’s a GitHub repo with all the files if you want to take your own shot at it. The energy efficiency number references the potential energy stored versus the energy produced. Obviously, if you are using some other energy source to lift the weight, that’s another calculation.

As you might expect, a practical system like this can be very large.

Peek Into IBM’s System/360 With Vintage Training Film

May 25, 2026 by No comments

Computing goes hand-in-hand with how to structure and access data, and this internal training film from IBM regarding file organization and data processing with System/360 is from a time when such decisions were crucial to system architecture.

Some trends never change, like storage costs over time.

The presenter talks about the transition from magnetic tape-based storage (in which data is stored and must be read sequentially) to DASD (direct access storage devices) which have more in common with modern mass storage media. The ability to access and process data at will instead of sequentially represented a tremendous opportunity to change how organizations handled data. System/360 redefined mainframe computing, introducing not just the concept of compatibility and interoperability of programs and data between systems, but also popularized the 8-bit byte.

It’s not a particularly long presentation and it doesn’t go into deep technical detail — it was primarily aimed at sales people — but it does offer an interesting peek into a time period in computing history that most of us have little or no direct experience with. Nevertheless some things never change, like a trend of plummeting storage prices (listed as cost per million characters) over time.

Check it out in the video embedded below, and if you’d like to know more about IBM’s System/360 we have you covered.

Thanks [Stephen Walters] for the tip.

Continue reading “Peek Into IBM’s System/360 With Vintage Training Film” →

Through-Glass Vias And The Long Road To Glass Substrates

May 25, 2026 by No comments
Credit: Keith Best, Semiengineering.
Credit: Keith Best, Semiengineering.

Glass-based substrates are slowly beginning to push out organic substrates commonly used in PCBs due to often superior material properties. One area where glass substrates have however struggled is with through-hole vias and providing the conductive copper path through them. A 2024 article by [Keith Best] gives a good overview of the topic, with recent news showing how much companies like Intel are pushing for glass substrates, specifically for the packaging of dies.

One major advantage with vias in glass substrates is that they can be much smaller, enabling smaller than 0.1 mm diameter holes with far finer pitch. The challenge here is to make perfect holes with a laser that are defect-free, as well as have the intended diameter.

After that this through-glass via (TGV) has to be coated or filled with copper, much like their organic equivalent. Said TGV can be fully filled with copper, or use plating and add dielectric filler. Detecting flaws in such a finished TGV is important.

In a 2025 review article of glass substrate technologies by [Pratik Nimbalkar] et al. published in Chips the state of the art at the time was covered. The need for ever higher-density integration options with ASICs is highlight here, especially now that many chips today consist of multiple interconnected dies inside a single package.

The complications of creating TGVs with femtosecond laser pulses in Borofloat 33 glass are highlighted by [Daniel Franz] et al. in a 2025 research article, with microcracks and backside ablation observed without proper precautions, something which previously was often resolved by an etching step following said laser drilling. The main issue here is the post-drilling residual stress from the thermal shock, which the authors demonstrate can be largely prevented with careful tweaking of the laser drilling parameters.

As pointed out in a 2024 review article by [Chen Yu] et al. glass substrates are useful for far more than just high-density chip packaging. Glass substrates are also chemically resistant, have a higher heat resistance, are largely transparent to RF and can be hermetically sealed against outside influences. This makes them great for various advanced sensors and communication devices.

Meanwhile, if you wanted to do some metal-depositing on glass at home, we covered this recently.

Z386: An Open-Source 80386 Built Around Original Microcode

May 25, 2026 by 7 Comments

There are many ways you can implement an Intel i386 CPU on an FPGA, with the use of original microcode probably being one of the most interesting approaches. This is what [nand2mario]’s z386 project does, with a recent blog post summarizing development on this FPGA project so far.

This project is similar to the previously developed z8086 project, which as one may guess does something similar, except for the Intel 8086 CPU. By executing the original microcode you’re basically guaranteeing close compatibility with the original hardware, though of course the sheer scale of this microcode between an 8086 and 80386 is quite different.

There’s a much larger instruction set with a correspondingly much more complicated internal state to keep track of, including all those newfangled features like memory management, paging and register debugging, as well extensions to protected mode that began with the i286.

Currently z386 runs on a number of FPGAs, including the Altera Cyclone V and Gowin GW5A, with performance equivalent to a ~70 MHz i386 albeit with slightly worse cycle efficiency, some of which could be due to the limited 16 kB cache compared to the 32+ kB cache in the fastest i386 CPUs. Either way, it’s more than enough to run all kinds of software, including games like DOOM.

Important to note is that the goal here isn’t to be more performant than cores such as for example ao486, but more as an archaeological reconstruction of the original hardware and its interaction with said microcode.

Top image: line-up of Intel 286, 386 and 486 CPUs. (Credit: Sgroey, Wikimedia)

Lost Version Of Amiga Unix Suddenly Reappears

May 25, 2026 by 8 Comments

Some of you may know there’s a version of UNIX for the Commodore Amiga, aptly called Amiga Unix or AMIX. There is an almost complete record of versions from 1.0 to 2.03, but 2.02 was lost media–until [Forgotten Computer] found it on an old Amiga.

It starts with an auction held for the 40 year anniversary of the Free Software Foundation where, by just one second, the highest bidder was too late. What do you do first with an artifact as valuable as an old FSF computer? You image the hard drive. Then you make several copies, including on different computers–after all, you wouldn’t want to lose the data on it. Preservation secured, the natural next thing is to boot it–and that’s when we see the magic 2.02c version number.
According to thorough digging by [Forgotten Computer], this version was–until now–lost.

In the video after the break, [Forgotten Computer] goes over what Amiga Unix is, the discovery process, and explores what’s on the disk–including FSF staples like GCC, G++ and core utilities like GNU less.
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3D Printing Space Cadet Pinball Into The Real World

May 25, 2026 by 8 Comments

Unless you’ve managed to avoid touching a Windows computer until after the Windows XP era, it’s pretty good odds you’ve played Space Cadet Pinball. Some of you may have even paid for the Mac port of Full Tilt! Pinball, the actual game the Windows freebee was supposed to demo. Unofficial ports exist for Linux as well, which means the one place nobody has ever played the game is, ironically, on a pinball table. [CNCDan]aims to change that in a video embedded below.

Ironically given [CNCDan]’s name, the parts he starts with — the two sorts of pop bumpers, the drop targets, slingshots, and delayed-drop hole– are all largely 3D-printed. While some of these parts are available commercially, it turns out that the scaling of the virtual pinball machine doesn’t match anything on offer, and rather than compromise [CNCDan] decided to do it himself, an attitude we absolutely respect.

All that’s left are the flippers– his first prototype wasn’t powerful enough–and a couple minor mechanisms before building the table. To do that, he’ll need high-resolution art worth printing. Not surprisingly, a game dating from 1995 doesn’t have high resolution assets available with which to do that. That kind of creativity isn’t in [CNCDan]’s wheelhouse, so if it is in yours and you want to collaborate, or know someone who does, you can reach [CNCDan] at his YouTube page. At the very least, he can pay you in playtime.

[CNCDan] often goes beyond his namesake, like with his SteamDeck-like handheld, or his 3D printed VR headset. Still, no guesses how he’s going to build the cabinet.

Continue reading “3D Printing Space Cadet Pinball Into The Real World” →

A diagram of a neutron generator is shown in the top portion of the image, with the physical version below.

A Benchtop Neutron Generator For The Home Reactor

May 25, 2026 by 10 Comments

There are a surprising number of experiments an amateur nuclear physicist can perform, from making a Geiger counter to fusing hydrogen atoms in a fusor. One project which we haven’t seen before is a neutron generator, such as the benchtop neutron generator made by [Rapp Instruments] (translated).

This particular generator takes a feedstock of pure deuterium, which it ionizes and accelerates into a titanium target. The first deuterium nuclei to hit the target react with it to form titanium deuteride, immobilizing them until more ions strike them and they undergo nuclear fusion. The fusion reaction mostly forms helium-4, but sometimes forms helium-3 and a free neutron, which is radiated away. The radiated neutrons are slowed down by a block of high-density polyethylene, and a portion of them strike a silver or indium foil wrapped around a Geiger counter tube. The neutrons activate the silver or indium, and the Geiger counter detects the resultant increase in radioactivity.

The design is a linear particle accelerator built inside an evacuated glass tube. It uses two high-voltage power supplies: a 20 kV supply which ionizes the deuterium gas fed into the tube, and a 100 kV supply which accelerates ions emitted from the source into the target. The target itself is surrounded by a cup-shaped electrode to capture secondary electrons emitted during impact. To prevent arcing, the tube needs to be at a very low pressure, reached by extensive use of an oil diffusion pump.

Radioactivity measurements of the silver and indium foils showed that the generator did work; when irradiating the silver foil for five minutes, it generated 175 counts per second after the neutron source was turned off. Plotting the count rate versus time suggested that a mixture of two silver isotopes was being generated, Ag-110 and Ag-108, based on their half-lives. Irradiation of indium produced a similar exponential decay in radiation.

We recommend checking out the rest of the site; it’s a gold mine of projects, such as this mass spectrometer. For more background on neutron generators, we’ve covered their theory and some of the more common varieties.