Why Games Work, And How To Build Them

December 13, 2025 by Donald Papp 5 Comments

Most humans like games. But what are games, exactly? Not in a philosophical sense, but in the sense of “what exactly are their worky bits, so we know how to make them?” [Raph Koster] aims to answer that in a thoughtful blog post that talks all about game design from the perspective of what, exactly, makes them tick. And we are right into that, because we like to see things pulled apart to learn how they work.

On the one hand, it’s really not that complicated. What’s a game? It’s fun to play, and we generally feel we know a good one when we see it. But as with many apparently simple things, it starts to get tricky to nail down specifics. That’s what [Raph]’s article focuses on; it’s a twelve-step framework for how games work, and why they do (or don’t) succeed at what they set out to do.

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Watch A Recording Lathe From 1958 Cut A Lacquer Master Record

December 13, 2025 by Donald Papp 6 Comments

Most of us are familiar with vinyl LPs, and even with the way in which they are made by stamping a hot puck of polyvinyl chloride (PVC) into a record. But [Technostalgism] takes us all the way back to the beginning, giving us a first-hand look at how a lacquer master is cut by a specialized recording lathe.

An uncut lacquer master is an aluminum base coated with a flawless layer of lacquer. It smells like fresh, drying paint.

Cutting a lacquer master is the intricate process by which lacquer disks, used as the masters for vinyl records, are created. These glossy black masters — still made by a company in Japan — are precision aluminum discs coated with a special lacquer to create a surface that resembles not-quite-cured nail polish and, reportedly, smells like fresh paint.

The cutting process itself remains largely unchanged over the decades, although the whole supporting setup is a bit more modernized than it would have been some seventy years ago. In the video (embedded below), we get a whole tour of the setup and watch a Neumann AM32B Master Stereo Disk Recording Lathe from 1958 cut the single unbroken groove that makes up the side of a record.

The actual cutting tool is a stylus whose movement combines the left and right channels and is heated to achieve the smoothest cuts possible. The result is something that impresses the heck out of [Technostalgism] with its cleanliness, clarity, and quality. Less obvious is the work that goes into arranging the whole thing. Every detail, every band between tracks, is the result of careful planning.

It’s very clear that not only is special equipment needed to cut a disk, but doing so effectively is a display of serious craftsmanship, experience, and skill. If you’re inclined to agree and are hungry for more details, then be sure to check out this DIY record-cutting lathe.
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Mentra Brings Open Smart Glasses OS With Cross-Compat

December 13, 2025 by Arya Voronova 5 Comments

There are a few very different pathways to building a product, and we gotta applaud the developers taking care to take the open-source path. Today’s highlight is [Mentra], who is releasing an open-source smart glasses OS for their own and others’ devices, letting you develop your smart glasses ideas just once, a single codebase applicable for multiple models.

Currently, the compatibility list covers four models, two of them Mentra’s (Live and Mach 1), one from Vuzix (Z100), and one from Even Realities (G1) — some display-only, and some recording-only. The app store already has a few apps that cover the basics, the repository looks lively, and if the openness is anything to go by, our guess is that we’re sure to see more.

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Condensing Diesel Heater Hack Is Dripping With Efficiency

December 13, 2025 by Tyler August 8 Comments

Not a huge percentage of our readers probably get their heat from diesel fuel, but it’s not uncommon in remote areas where other fuels are hard to come-by. If you’re in one of those areas, this latest hack from [Hangin with the Hursts] could save you some change, or keep you ̶2̶0̶%̶ ̶c̶o̶o̶l̶e̶r̶ 25% warmer on the same fuel burn.

It’s bog simple: he takes his off-the-shelf hydronic diesel heater, which is already 71% efficient according to a previous test, and hooks its exhaust to a heat exchanger. Now, you don’t want to restrict the exhaust on one of these units, as that can mess with the air fuel mix, but [Hurst] gets around that with a 3″ intercooler meant for automotive intake. Sure, it’s not made for exhaust gas, but this is a clean-burning heater, and it wouldn’t be a hack if some of the parts weren’t out of spec.

Since it’s a hydronic heater, he’s able to use the exhaust gas to pre-heat the water going into the burner. The intercooler does a very good job of that, sucking enough heat out of the exhaust to turn this into a condensing furnace. That’s great for efficiency — he calculates 95%, a number so good he doesn’t trust it — but not so good for the longevity of the system, since this intercooler isn’t made to deal with the slightly-acidic condensation. The efficiency numbers are combustion efficiency, to be clear. He’s only accounting for the energy in the diesel fuel, not the energy that heats the water in his test, for the record; the electrical power going into the blower is considered free. That’s fair, since that’s how the numbers are calculated in the heating industry in general — the natural gas furnace keeping this author from freezing to death, for example, is a condensing unit that is also 95% efficient.

Another thing you can do to get the most from your diesel heating fuel is add some brains to the operation. Since this is a hydronic system, the cheapest option, long-term, might be to add some solar energy to the water. Sunlight is free, and diesel sure isn’t getting any cheaper.

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Get Statistical About Your Pet With This Cat Tracking Dashboard

December 13, 2025 by Lewin Day 3 Comments

Cats can be wonderful companions, but they can also be aloof and boring to hang out with. If you want to get a little more out of the relationship, consider obsessively tracking your cat’s basic statistics with this display from [Matthew Sylvester].

The build is based around the Seeedstudio ReTerminal E1001/E1002 devices—basically an e-paper display with a programmable ESP32-S3 built right in. It’s upon this display that you will see all kinds of feline statistics being logged and graphed. The data itself comes from smart litterboxes, with [Matthew] figuring out how to grab data on weight and litterbox usage via APIs. In particular, he’s got the system working with PetKit gear as well as the Whisker Litter Robot 4. His dashboard can separately track data for four cats and merely needs the right account details to start pulling in data from the relevant cat cloud service.

For [Matthew], the build wasn’t just a bit of fun—it also proved very useful. When one of his cats had a medical issue recently, he was quickly able to pick up that something was wrong and seek the help required. That’s a pretty great result for any homebrew project. It’s unrelated, too, but Gnocci is a great name for a cat, so hats off for that one.

We’ve featured some other fun cat-tracking projects over the years, too. If you’re whipping up your own neat hardware to commune with, entertain, or otherwise interact with your cat, don’t hesitate to let us know on the tipsline.

User Serviceable Parts

December 13, 2025 by Elliot Williams 14 Comments

Al and I were talking on the podcast about the Home Assistant home automation hub software. In particular, about how devilishly well designed it is for extensibility. It’s designed to be added on to, and that makes all of the difference.
That doesn’t mean that it’s trivial to add your own wacky control or sensor elements to the system, but that it’s relatively straightforward, and that it accommodates you. If your use case isn’t already covered, there is probably good documentation available to help guide you in the right direction, and that’s all a hacker really needs. As evidence for why you might care, take the RTL-HAOS project that we covered this week, which adds nearly arbitrary software-defined radio functionality to your setup.

And contrast this with many commercial systems that are hard to hack on because they are instead focused on making sure that the least-common-denominator user is able to get stuff working without even reading a single page of documentation. They are so focused on making everything that’s in-scope easy that they spend no thought on expansion, or worse they actively prevent it.

Of course, it’s not trivial to make a system that’s both extremely flexible and relatively easy to use. We all know examples where the configuration of even the most basic cases is a nightmare simply because the designer wanted to accommodate everything. Somehow, Home Assistant has managed to walk the fine line in the middle, where it’s easy enough to use that you don’t have to be a wizard, but that you can make it do what you want if you are, and hence it got spontaneous hat-tips from both Al and myself. Food for thought if you’re working on a complex system that’s aimed at the DIY / hacker crowd.

A biohacker with her lactose-rich slurry

Biohack Your Way To Lactose Tolerance (Through Suffering)

December 13, 2025 by Tyler August 36 Comments

A significant fraction of people can’t handle lactose, like [HGModernism]. Rather than accept a cruel, ice cream free existence, she decided to do something you really shouldn’t try: biohacking her way to lactose tolerance.

The hack is very simple, and based on a peer reviewed study from the 1990s: consume lactose constantly, and suffer constantly, until… well, you can tolerate lactose. If you’re lactose intolerant, you’re probably horrified at the implications of the words “suffer constantly” in a way that those milk-digesting-weirdos could never understand. They probably think it is hyperbole; it is not. On the plus side, [HGModernism]’s symptoms began to decline after only one week.

The study dates back to the 1980s, and discusses a curious phenomenon where American powdered milk was cluelessly distributed during an African famine. Initially that did more harm than good, but after a few weeks mainlining the white stuff, the lactose-intolerant Africans stopped bellyaching about their bellyaches.

Humans all start out with a working lactase gene for the sake of breastfeeding, but in most it turns off naturally in childhood. It’s speculated that rather than some epigenetic change turning the gene for lactose tolerance back on — which probably is not possible outside actual genetic engineering — the gut biome of the affected individuals shifted to digest lactose painlessly on behalf of the human hosts. [HGModernism] found this worked but it took two weeks of chugging a slurry of powdered milk and electrolyte, formulated to avoid dehydration due to the obvious source of fluid loss. After the two weeks, lactose tolerance was achieved.

Should you try this? Almost certainly not. [HGModernism] doesn’t recommend it, and neither do we. Still, we respect the heck out any human willing to hack the way out of the limitations of their own genetics. Speaking of, at least one hacker did try genetically engineering themselves to skip the suffering involved in this process. Gene hacking isn’t just for ice-cream sundaes; when applied by real medical professionals, it can save lives.

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