Mockup of a printed copy of the Little OS Book

One Book To Boot Them All

April 2, 2025 by 19 Comments

Somewhere in the universe, there’s a place that lists every x86 operating system from scratch. Not just some bootloaders, or just a kernel stub, but documentation to build a fully functional, interrupt-handling, multitasking-capable OS. [Erik Helin and Adam Renberg] did just that by documenting every step in The Little Book About OS Development.

This is not your typical dry academic textbook. It’s a hands-on, step-by-step guide aimed at hackers, tinkerers, and developers who want to demystify kernel programming. The book walks you through setting up your environment, bootstrapping your OS, handling interrupts, implementing virtual memory, and even tackling system calls and multitasking. It provides just enough detail to get you started but leaves room for exploration – because, let’s be honest, half the fun is in figuring things out yourself.

Completeness and structure are two things that make this book stand out. Other OS dev guides may give you snippets and leave you to assemble the puzzle yourself. This book documents the entire process, including common pitfalls. If you’ve ever been lost in the weeds of segmentation, paging, or serial I/O, this is the map you need. You can read it online or fetch it as a single 75-page long PDF.

Mockup photo source: Matthieu Dixte

Programmer’s Macro Pad Bangs Out Whole Functions

April 2, 2025 by 24 Comments

Macro pads are handy for opening up your favorite programs or executing commonly used keyboard shortcuts. But why stop there?

That’s what [Jeroen Brinkman] must have been thinking while creating the Programmer’s Macro Pad. Based on the Arduino Pro Micro, this hand-wired pad is unique in that a single press of any of its 16 keys can virtually “type” out multiple lines of text. In this case, it’s a capability that’s being used to prevent the user from having to manually enter in commonly used functions, declarations, and conditional statements.

For example, in the current firmware, pressing the “func” key will type out a boilerplate C function:

int () { //
;
return 0;
}; // f

It will also enter in the appropriate commands to put the cursor where it needs to be so you can actually enter in the function name. The other keys such as “array” and “if” work the same way, saving the user from having to enter (and potentially, even remember) the correct syntax.

The firmware is kept as simple as possible, meaning that the functionality of each key is currently hardcoded. Some kind of tool that would let you add or change macros without having to manually edit the source code and flash it back to the Arduino would be nice…but hey, it is a Programmers Macro Pad, after all.

Looking to speed up your own day-to-day computer usage? We’ve covered a lot of macro pads over the years, we’re confident at least a few of them should catch your eye.

FLOSS Weekly Episode 827: Yt-dlp, Sometimes You Can’t See The Tail

April 2, 2025 by 3 Comments

This week, Jonathan Bennett chats with Bashonly about yt-dlp, the audio/video downloader that carries the torch from youtube-dl! Why is this a hard problem, and what does the future hold for this swiss-army knife of video downloading? Watch to find out!

Continue reading “FLOSS Weekly Episode 827: Yt-dlp, Sometimes You Can’t See The Tail” →

Supercon 2024: Rethinking Body Art With LEDs

April 2, 2025 by 3 Comments

Tattoos. Body paint. Henna. All these are popular kinds of body art with varying histories and cultural connotations, many going back centuries or even longer. They all have something in common, though—they all change how the body reflects light back to the viewer. What if, instead, body art could shine a light of its very own?

This is the precise topic which [Katherine Connell] came to discuss at the 2024 Hackaday Supercon. Her talk concerns rethinking body art with the use of light emitting diodes—and is both thoroughly modern and aesthetically compelling. Beyond that, it’s an engineering development story with liquid metal and cutting-edge batteries that you simply don’t want to miss!

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70 DIY Synths On One Webpage

April 2, 2025 by 14 Comments

If you want to dip your toes into the deep, deep water of synth DIY but don’t know where to start, [Atarity] has just the resource for you. He’s compiled a list of 70 wonderful DIY synth and noise-making projects and put them all in one place. And as connoisseurs of the bleepy-bloopy ourselves, we can vouch for his choices here.

The collection runs the gamut from [Ray Wilson]’s “Music From Outer Space” analog oddities, through faithful recreations like Adafruit’s XOXBOX, and on to more modern synths powered by simple microcontrollers or even entire embedded Linux devices. Alongside the links to the original projects, there is also an estimate of the difficulty level, and a handy demo video for every example we tried out.

Our only self-serving complaint is that it’s a little bit light on the Logic Noise / CMOS-abuse side of synth hacking, but there are tons of other non-traditional noisemakers, sound manglers, and a good dose of musically useful devices here. Pick one, and get to work!

Australia’s Steady March Towards Space

April 2, 2025 by 29 Comments

The list of countries to achieve their own successful orbital space launch is a short one, almost as small as the exclusive club of states that possess nuclear weapons. The Soviet Union was first off the rank in 1957, with the United States close behind in 1958, and a gaggle of other aerospace-adept states followed in the 1960s, 1970s, and 1980s. Italy, Iran, North Korea and South Korea have all joined the list since the dawn of the new millennium.

Absent from the list stands Australia. The proud island nation has never stood out as a player in the field of space exploration, despite offering ground station assistance to many missions from other nations over the years. However, the country has continued to inch its way to the top of the atmosphere, establishing its own space agency in 2018. Since then, development has continued apace, and the country’s first orbital launch appears to be just around the corner.

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The Lowly Wall Wart Laid Bare

April 2, 2025 by 18 Comments

Getting a look at the internals of a garden variety “wall wart” isn’t the sort of thing that’s likely to excite the average Hackaday reader. You’ve probably cracked one open yourself, and even if you haven’t, you’ve likely got a pretty good idea of what’s inside that sealed up brick of plastic. But sometimes a teardown can be just as much about the journey as it is the end result.

Truth be told, we’re not 100% sure if this teardown from [Brian Dipert] over at EDN was meant as an April Fool’s joke or not. Certainly it was posted on the right day, but the style is close enough to some of his previous work that it’s hard to say. In any event, he’s created a visual feast — never in history has an AC/DC adapter been photographed so completely and tastefully.

An Ode to the Diode

[Brian] even goes so far as to include images of the 2.5 lb sledgehammer and paint scraper that he uses to brutally break open the ultrasonic-welded enclosure. The dichotomy between the thoughtful imagery and the savage way [Brian] breaks the device open only adds to the surreal nature of the piece. Truly, the whole thing seems like it should be part of some avant garde installation in SoHo.

After he’s presented more than 20 images of the exterior of the broken wall wart, [Brian] finally gets to looking at the internals. There’s really not much to look at, there’s a few circuit diagrams and an explanation of the theory behind these unregulated power supplies, and then the write-up comes to a close as abruptly as it started.

So does it raise the simple teardown to an art form? We’re not sure, but we know that we’ll never look at a power adapter in quite the same way again.