A web interface is shown providing information about a cellular network base station.

Running Your Own 3G Network

May 9, 2026 by Aaron Beckendorf 13 Comments

CDMA2000 was one of the protocols defined for 3G networks and is now years out of date and being phased out worldwide. Nevertheless, there are still vast numbers of phones that will happily connect to it, creating an opportunity for hackers seeking to run their own cellular networks. [Chrismoos] recently made this endeavour significantly easier by releasing 1xBTS, a Rust implementation of the lower three layers of a CDMA2000 network.

The lowest layer of the stack is an SDR for the actual radio communications. It’s been tested with the USRP B200 and B210, the LimeSDR Mini 2, and the BladeRF Micro 2.0. The code might work with certain other SDRs using the SoapySDR abstraction layer. The SDR is controlled by the base station (BTS) software, which, in turn, is controlled by the base station controller (BSC) over an Abis link. The BSC manages channels and mobile device associations, and exchanges frames with the mobile switching center (MSC), which handles message switching.

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The Noctua Fan Files And The Limits Of 3D Printing PC Fans

May 9, 2026 by Maya Posch 21 Comments

After Noctua recently released CAD files for a range of their computer fans, one of the first thoughts that popped up for most people was: Can you just to 3D print their fans? Even though Noctua begs you not to 3D print the files and even says they changed the design slightly so it wouldn’t be the same anyway, the question persists. Fortunately, [Steve] of Gamers Nexus is here to help us answer the question of whether it makes sense to 3D print a computer fan.

Unsurprisingly, the answer is mostly a resounding ‘no’. After reworking the original CAD models to be both printable on a Bambu Lab FDM printer and printing the parts in PLA, the arguably most important part, the motor, still had to be sourced from an original Noctua fan. Although you could source a cheaper motor, that could change the fan’s characteristics.

The other issue is materials. The special polymer that Noctua uses for its fans is designed not to change shape significantly when the fan blades are spinning, whereas PLA and basically every other thermoplastic will likely deform enough to hit the inside of the fan with the blades. For this reason, a 3 mm gap was used in the PLA print compared with the approximately 0.5 mm gap of the original Noctua fan.

Using the professional fan tester and semi-anechoic chamber over at Gamers Nexus, the original and replica fans were compared, showing that the 3D-printed fan had a similar noise profile but produced only about half the airflow. This is likely due to the blade shape and angle, the increased gap, and probably a dozen other details that presumably justify putting a cool $40 down for the original fan.

In short, you’re probably best off using these Noctua fan CAD models for fit testing in a larger CAD model, or 3D printing it for a similar purpose, rather than for a functional fan design. At least now we know. Thanks, [Steve].

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Remembering The BBC Computer Literacy Project

May 9, 2026 by Jenny List 15 Comments

There comes a point in everybody’s life when things that they were a part of are presented as history, and for the 8-bit generation, that time is now. It’s interesting to see the early history of 8-bit home computers presented as history, not from a 2026 perspective but from the early 1990s. The BBC archive has recently posted a retrospective from 1992 looking at ten years of the Computer Literacy Project, a British government programme intended to equip the young people of the 1980s with the skills they would need to approach the information age. It’s a much more immediate history of something which was largely still in place at the time, making it a time capsule in which this past isn’t quite the other country we see it as today.

The Computer Literacy Project was run by the nation’s broadcaster and included a raft of TV programming about computers, as well as the commissioning of a machine specifically for the project. You know this machine as the Acorn BBC Micro, and aside from eventually providing the genesis of what would become ARM, it remains one of the most high-spec 8-bit machines in terms of built-in hardware. We hear from the luminaries of Acorn about the development of this machine, and then the film moves into some of the wider cultural effects.

If you were there, you’ll doubtless remember some of the TV programmes featured, and you might have used a BBC Micro at school. If you weren’t there, it’s an encapsulation of the promise on offer in that era, an optimism that seems sad when you reflect that educational computing descended into learning Microsoft Word during the following decade. It would be another two decades before the Raspberry Pi and BBC micro:bit picked up that fallen torch.

The Beeb, it seems, has long had an interest in home computers. Schools, too.

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Machining A Two-Stroke Engine Out Of Aluminium

May 9, 2026 by Maya Posch 24 Comments

Recently [Camden Bowen] took a swing at machining a two-stroke engine out of billet aluminium, following adventures in 3D printing such an engine, as well as building one out of parts largely sourced from a hardware store. The sketchiest part here is probably the use of only a basic mill and lathe, making the milling of certain shapes a definite OSHA violation.

Two-stroke internal combustion engines are pretty simple from a mechanical point of view, with designs readily available. Add in a suitable material to machine and a modicum of machining and welding skills, and presto, you got yourself a not too shabby looking engine.

Of course, back in reality things are a bit more hairy. Not only are there many different ways to produce the parts – with some coming with a time penalty, monetary penalty, or both – but there are also myriad ways to hurt yourself and/or others. Fortunately [Camden] scraped by with just some (expensive) lessons learned and a major ruined part.

The final design features a single cylinder, with an initial pressure test showing a solid 150 PSI (10 bar) of compression. With that encouraging sign, a coil pack and contactor were added for some spark and a test run with the usual premixed gasoline-oil fuel.

Boringly, the engine mostly just runs and work as it should. This is of course not unexpected, much like how following the recipe for a pie produces said pie. But it does demonstrate how easy things are when you do not stray off the beaten path. The only significant issue was the flywheel wobbling slightly, likely due to a small manufacturing glitch, but this should not cause too many issues.

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Copy Or Redesign?

May 9, 2026 by Elliot Williams 5 Comments

We got asked a great question in the mailbag segment on the Podcast this week: are there hacks that we have read about on Hackaday that we use in our everyday life? The answer was absolutely yes, and I loved Tom’s take it often goes the other way – he sees a hack, tests it out, and then writes it up.

But I started looking around the office and I found more examples of projects that were absolutely inspired by projects I had seen on Hackaday, yet weren’t the same. I made a DIY mechanical keyboard because I saw someone else do it. There are a few home-made battery packs that I probably wouldn’t have attempted without having read about someone doing the same thing. I riffed on [Ted Yapo]’s Tritiled project, making a slightly inferior, but workable knockoff, and they’ve been glowing for many years now.

That got me to thinking about reproducing a project versus taking inspiration from it, and though I enjoy both, I’m find myself most often in the “inspiration” mode. I just can’t leave well enough alone, even when I’m fundamentally copying someone. NIH syndrome? Expediency? Probably both, and sometimes with a dose of hubris or feature creep.

Looking back at [Ted]’s TritiLED, though, I found some great examples in both the rebuild and redesign modes on Hackaday.io. [schlion]’s Making Ted Yapo’s TritiLED couldn’t be a clearer example of the former, and it’s great to look over his shoulder and appreciate all the lessons he learned along the way. [Stephan Walter]’s Yet another ultra low power LED is inspired by [Christoph Tack]’s Ultra low power LED, which is in turn inspired by [Ted]’s project, like a conceptual grandchild.

In a way, I look at this like with music: sometimes you play the notes the way they were written down, and sometimes you riff on someone else’s theme. Both are equally valid, and both owe a debt to the upstream source. Is Hackaday the hackers’ jazz club? And which of these modes do you find yourself working in most?

It’s An Apple Lisa, On A FPGA

May 9, 2026 by Jenny List 5 Comments

Most of us will know that Apple’s precursor to the Macintosh series of computers was a machine called the Lisa. Something of a behemoth compared to those early Macs, it had a price to match and wasn’t a commercial success. Working Lisas survive, but unlike a Mac you won’t find many at your local swapmeet. But what if you really must try this early Apple GUI? Never fear, because [AlexElectronics] is here with a much more accessible version on a FPGA.

This Lisa has a surprisingly large PCB compared to the size of the FPGA, because of the number of connectors. It takes the approach of mixing new and old in interfaces, for example as well as original Lisa keyboard and mouse support, you can also use modern USB versions. There’s also an HDMI output for a modern monitor, and an SD card. Unexpectedly alongside the FPGA there’s a 40-pin DIP, it’s a UART chip because there’s no handy pre-built one for that particular chip. We’re told it will be up on GitHub when finalized.

Keeping old computers alive, especially rare ones, is hard. We like projects like this one, and we hope to see more developments. Meanwhile you can see the machine in the video below.

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Getting A Proprietary-Bus GPU Onto PCIe Enables Cheaper Local LLMs, For Now

May 9, 2026 by Tyler August 27 Comments

If you’ve been thinking of getting into self-hosting generative AI, but don’t have a big budget for hardware, you might want to check out [Hardware Haven]’s latest video on an unusually cheap GPU option — but you’ll have to do so quickly, before the market realizes the chance for arbitrage and prices rise accordingly.

He’s gotten a hold of a 16 GB NVidia V100 card for only about a hundred bucks, mostly because it’s not easy to plug in, being on an SXM2 socket rather than the PCIe bus. SXM is a server architecture, and not something you’re likely to get on your motherboard. Another hundred got him an adapter board to fit this enterprise GPU on a consumer motherboard. That’s still a lot less than the PCIe version of the same card, which will likely set you back a thousand or more unless you get very lucky on eBay.

It’s not the newest card, dating back from 2017, but that doesn’t mean it can’t run the latest open models. After 3D printing a fan shroud for the thing so it didn’t cook itself, adding very slightly to the build cost, [Hardware Haven] set to work seeing what it could do. Going head-to-head against an RTX 3060 12 GB, the older V100 delivered more tokens per second at a slightly higher efficiency — but much higher idle power.

Still, it’s nice to see a cheap way to get into local AI, even if it might not still be cheap by the time you read this. Once you have the hardware, you might want some easy software options so you don’t have to spend all day on setup. Of course you only need a hefty GPU to run larger models — you can get into hosting your own AI on a Raspberry Pi, if you’re patient.

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