A RISC-V Operating System Instruction Manual

May 26, 2025 by 1 Comment

To some, an operating system is a burden or waste of resources, like those working on embedded systems and other low-power applications. To others it’s necessary, abstracting away hardware so that higher-level programming can be done. For most people it’s perhaps not thought of at all. But for a few, the operating system is the most interesting piece of software running on a computer and if you’d like to investigate what makes this often overlooked aspect of computer science interesting, take a look at this course on operating systems from Cornell University.

The operating system itself is called Earth and Grass Operating System because it splits the functionality of the operating system into three separate parts. The Earth layer involves dealing with hardware, the Grass layer involves hardware-independent aspects, and a third application layer implements other key operating system features. It’s built for a RISC-V processor, since that instruction set is completely open source and transparent about what it’s doing. It’s also incredibly small, coming in at around 2000 lines of code. The course covers nine areas, with the first six being core operating system functions and the remaining three covering more advanced operating system concepts.

For understanding the intricacies and sometimes mysterious ways that operating systems work, a course like this can go a long way into unraveling those mysteries and developing a deeper understanding of how it brings the hardware to work for higher-level software. We actually featured this operating system two years ago, before this course was created, which covers this project for those who like to take a more self-directed approach, or simply want a lightweight OS for a RISC-V system.

Wayback Proxy Lets Your Browser Party Like It’s 1999

May 26, 2025 by 14 Comments

This project is a few years old, but it might be appropriate to cover it late since [richardg867]’s Wayback Proxy is, quite literally, timeless.

It does, more-or-less, what it says as on the tin: it is an HTTP proxy that retrieves pages from the Internet Archive’s Wayback Machine, or the Oocities archive of old Geocities sites. (Remember Geocities?) It is meant to sit on a Raspberry Pi or similar SBC between you and the modern internet. A line in a config file lets you specify the exact date. We found this via YouTube in a video by [The Science Elf] (embedded below, for those of you who don’t despise YouTube) in which he attaches a small screen and dial to his Pi to create what he calls the “Internet Time Machine” using the Wayback Proxy. (Sadly [The Science Elf] did not see fit to share his work, but it would not be difficult to recreate the python script that edits config.json.)

What’s the point? Well, if you have a retro-computer from the late 90s or early 2000s, you’re missing out a key part of the vintage experience without access to the vintage internet. This was the era when desktops were being advertised as made to get you “Online”. Using Wayback Proxy lets you relive those halcyon days– or live them for the first time, for the younger set. At least relive those of which parts of the old internet which could be Archived, which sadly isn’t everything. Still, for a nostalgia trip, or a living history exhibit to show the kids? It sounds delightful.

Of course it is possible to hit up the modern web on a retro PC (or on a Mac Plus). As long as you’re not caught up in an internet outage, as this author recently was.

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2025 Pet Hacks Contest: A Barrel Of Fun For Your Dog

May 26, 2025 by 3 Comments

If you ask someone for a piece of received opinion about Bernese mountain dogs, the chances are that the tale of their carrying barrels of brandy round their necks for the revival of those lost in the snow. It’s a story of uncertain provenance and may indeed be a myth, but that hasn’t stopped [Saren Tasciyan] 3D printing one for their faithful hound. In its own way it too is a saviour, for as well as a small camera, it carries a supply of dog poop bags.

It’s a two part print, held together with strong magnets. Waterproofing is achieved using liberal quantities of hot glue. There’s a protrusion on one side designed to take an action camera for a dog’s-eye-view of the world. The files are downloadable, so your pooch can have one too if you like. We are wondering whether a couple of miniatures of brandy might just fit in there as well.

It’s is part of the 2025 Pet Hacks contest, so if this has whetted your appetite, expect more. If your dog carries around something you’ve made, how about making it an entry of your own?

2025 Hackaday Pet Hacks Contest

Mouse Model Suggests Starch-Based Plastics Are Still Bad For You

May 26, 2025 by 48 Comments

To paraphrase The Simpsons: plastics are the solution to – and cause of – all of mankind’s problems. Nowhere is this more clear in the phenomenon of microplastics. Some have suggested that alternative bioplastics made out of starch could be the solution here, as the body might be able to digest and disassemble these plastic fragments better. Unfortunately, a team of Chinese researchers put this to the test using mice, with the results suggesting that starch-based plastics do not change the harm to tissues and organs.

We previously looked at this harm from micro- and nanoplastics (MNP), with humans and their brains at autopsy showing a strong correlation between disease and presence of MNPs. In this recent study mice were split up into three groups, for either no, low or high levels of these bioplastics in their food. At autopsy, the mice exposed to the bioplastics all showed damage to organs, including the same gene-regulation issues and inflammation markers as seen with other plastics.

Despite these results, researchers question how useful these results are, as they pertain to modified starches with known biodegradability issues, while starch by itself is absolutely digestible when it’s in the form of potato chips, for instance. Perhaps the trick here is to make bioplastics that are still useful as plastics, and yet as harmless to ingest as said potato chips.

Not that we recommend eating bioplastics, mind you; potato chips are definitely tastier.

Intercepting And Decoding Bluetooth Low Energy Data For Victron Devices

May 26, 2025 by 12 Comments

[ChrisJ7903] has created two Ardiuno programs for reading Victron solar controller telemetry data advertised via BLE. If you’re interested in what it takes to use an ESP32 to sniff Bluetooth Low Energy (BLE) transmissions, this is a master class.

The code is split into two main programs. One program is for the Victron battery monitor and the other is for any Victron solar controller. The software will receive, dissect, decrypt, decode, and report the data periodically broadcast from the devices over BLE.

The BLE data is transmitted in Link-Layer Protocol Data Units (PDUs) which are colloquially called “packets”. In this particular case the BLE functionality for advertising, also known as broadcasting, is used which means the overhead of establishing connections can be avoided thereby saving power.

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NASA Is Shutting Down The International Space Station Sighting Website

May 26, 2025 by 36 Comments

Starting on June 12, 2025, the NASA Spot the Station website will no longer provide ISS sighting information, per a message recently sent out. This means no information on sighting opportunities provided on the website, nor will users subscribed via the website receive email or text notifications. Instead anyone interested in this kind of information will have to download the mobile app for iOS or Android.

Obviously this has people, like [Keith Cowing] over at Nasa Watch, rather disappointed, due to how the website has been this easy to use resource that anyone could access, even without access to a smart phone. Although the assumption is often made that everyone has their own personal iOS or Android powered glass slab with them, one can think of communal settings where an internet café is the sole form of internet access. There is also the consideration that for children a website like this would be much easier to access. They would now see this opportunity vanish.

With smart phone apps hardly a replacement for a website of this type, it’s easy to see how the app-ification of the WWW continues, at the cost of us users.

Pico-mac-nano Fits Working Macintosh On Barbie’s Desk

May 26, 2025 by 13 Comments

Have you ever looked in a doll house and said “I wish those dolls had a scale replica of a 1984 Macintosh 128K that could be operated by USB?” — well, us neither, but [Nick Gillard] gives us the option with his 63mm tall Pico-mac-nano project.

As you might imagine, this project got its start with the RP2040-based Pico Mac project by [Matt Evans], which we covered

The collector’s edition will come with a lovely box, but what’s in it is still open source so you can make your own.

before. [Nick] saw that, built it, and was delighted by it enough to think that if the Mac could run on such tiny hardware, how small could build a fully-usable replica Mac? The answer was 63 mm tall– at 5.5:1, that’s technically under the 6:1 scale that Barbie operates on, but if we had such a dollhouse we’d absolutely put one of these in it. (You just know Barbie’s an Apple kind of girl.)

The size was driven by the screen, which is a 2″ TFT panel with 480 x 640 pixel native resolution. Here [Nick] cheats a tiny bit– rather than trying to rewrite the PicoMac to output 640 x 480 and rotate the screen, he keeps the screen in portrait mode and drives it at 480 x 342 px. Sure, it’s not a pixel-perfect output, but no LCD is going to be a perfect stand in for a CRT, and who is going to notice 32 pixels on a 2″ screen? Regardless, that set the height of the computer, which is built around the portrait display. A highly detailed, and to our eyes, accurate replica of the original Macintosh case was printed to fit the LCD, coming in at the aforementioned 63mm tall.

Unfortunately this means the floppy drive could not be used for micro SD access– there is an SD card reader on this unit, but it’s on the back, along with a USB-C port, which is roughly where the mouse and keyboard ports are supposed to be, which is a lovely detail. Also delightful is the choice of a CR2 lithium battery for power, which is a form factor that will look just a bit familiar if you’ve been inside one of these old Macs.

[Nick] has posted the 3D designs and modified pico mac firmware to a GitHub repository, but if you’re looking for a charming desk ornament and don’t have the time to build your own, he will also be selling these (both kits and fully assembled units) via 1bitrainbow, which is the most delightfully retro web store we’ve seen of late.

If Classic MacOS isn’t good enough for you, how about linux? You won’t enjoy it as much, but it will run on the RP2040.