Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The C64 Keyboard

[Jean] wrote into the tips line (the system works!) to let all of us know about his hacked and hand-wired C64 keyboard, a thing of beauty in its chocolate-brown and 9u space bar-havin’ glory.

A C64 keyboard without the surrounding C64.
Image by [Jean] via GitHub
This Arduino Pro Micro-based brain transplant began as a sketch, and [Jean] reports it now has proper code in QMK. But how is a person supposed to use it in 2025, almost 2026, especially as a programmer or just plain serious computer user?

The big news here is that [Jean] added support for missing characters using the left and right Shift keys, and even added mouse controls and Function keys that are accessed on a layer via the Shift Lock key. You can see the key maps over on GitHub.

I’ll admit, [Jean]’s project has got me eyeing that C64 I picked up for $12 at a thrift store which I doubt still works as intended. But don’t worry, I will test it first.

Fortunately, it looks like [Jean] has thought of everything when it comes to reproducing this hack, including the requisite C64-to-Arduino pinout. So, what are you waiting for?

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34-Year-Old Macintosh ROM Bug Revealed By Emulator

Generally, you’d hope that your computer manufacturer got the ROM just right before shipping your computer. As [Doug Brown] found out, Apple actually fumbled this with the release of the Macintosh Classic II several decades ago. And yet… the machines worked! That turns out to be due to a rather weird low-level quirk, as recent tinkering in an emulator revealed. 

The bug was revealed when [Doug] was experimenting with the emulated Macintosh Classic II in MAME. He was exploring keyboard shortcuts for launching the debugger, but soon found a problem. He needed to load MacsBug to enable the debugging shortcut, and that required the use of 32-bit addressing. However, the emulated system wouldn’t boot in this mode at all, instead landing on a Sad Mac error screen.

Heavy debugging ensued, which makes for great reading if you love to chase problems on an instruction-by-instruction basis. Ultimately, [Doug’s] conclusion was a mindboggling one. He determined that the crash in MAME came down to a difference between the emulator’s behaviour versus the original Motorola 68030 CPU in the Classic II. There was simply a problematic undocumented instruction baked into the ROM. The real CPU runs this undocumented instruction, which modifies a certain register, allowing boot without issue. Meanwhile, the emulated CPU tries to execute the bad instruction, fails to modify the right register, and everything falls in a heap. [Doug] speculates that had the 68030 CPU hadn’t hidden the bug, Apple’s engineers might have found it many years ago. He even proved his theory by whipping up multiple custom ROMs to verify what was going on.

We love it when bugs from decades past rear their heads; we love it even more when they get fixed. If you’re chasing down issues with an Amiga or you’re ironing out the kinks in software for the Acorn Archimedes, be sure to let us know on the tips line.

[via Tom’s Hardware, thanks to Jason Morris for the tip!]

Bridging RTL-433 To Home Assistant

If you’ve got an RTL-SDR compatible receiver, you’ve probably used it for picking up signals from all kinds of weird things. Now, [Jaron McDaniel] has built a tool to integrate many such devices into the world of Home Assistant.

It’s called RTL-HAOS, and it’s intended to act as a bridge. Whatever you can pick up using the RTL_433 tool, you can set up with Home Assistant using RTL-HAOS. If you’re unfamiliar with RTL_433, it’s a multitalented data receiver for picking up all sorts of stuff on a range of bands using RTL-SDR receivers, as well as a range of other hardware. While it’s most closely associated with products that communicate in the 433 MHz band, it can also work with products that talk in 868 MHz, 315 MHz, 345 MHz, and 915 MHz, assuming your hardware supports it. Out of the box, it’s capable of working with everything from keyless entry systems to thermostats, weather stations, and energy monitors. You can even use it to listen to the tire pressure monitors in your Fiat Abarth 124 Spider, if you’re so inclined.

[Jaron’s] tool integrates these devices nicely into Home Assistant, where they’ll appear automatically thanks to MQTT discovery. It also offers nice signal metrics like RSSI and SNR, so you can determine whether a given link is stable. You can even use multiple RTL-SDR dongles if you’re so inclined. If you’re eager to pull some existing environmental sensors into your smart home, this may prove a very easy way to do it.

The cool thing about Home Assistant is that hackers are always working to integrate more gear into the ecosystem. Oftentimes, they’re far faster and more efficient at doing this than big-name corporations. Meanwhile, if you’re working on your own hacks for this popular smart home platform, we’d probably like to know about it. Be sure to hit up the tips line in due time.

Hackaday Podcast Episode 348: 50 Grams Of PLA Hold A Ton, Phreaknic Badge Is Off The Shelf, And Hackers Need Repair Manuals

Join Hackaday Editors Elliot Williams and Tom Nardi as they go over their picks for the best stories and hacks from the previous week. Things start off with a warning about the long-term viability of SSD backups, after which the discussion moves onto the limits of 3D printed PLA, the return of the Pebble smart watch, some unconventional aircraft, and an online KiCad schematic repository that has plenty of potential. You’ll also hear about a remarkable conference badge made from e-waste electronic shelf labels, filling 3D prints with foam, and a tiny TV powered by the ESP32. The episode wraps up with our wish for hacker-friendly repair manuals, and an interesting tale of underwater engineering from D-Day.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

As always, this episode is available in DRM-free MP3.

Continue reading “Hackaday Podcast Episode 348: 50 Grams Of PLA Hold A Ton, Phreaknic Badge Is Off The Shelf, And Hackers Need Repair Manuals”

Mac System 7 On A G4? Why Not!

Over the many years Apple Computer have been in operation, they have made a success of nearly-seamlessly transitioning multiple times between both operating systems and their underlying architecture. There have been many overlapping versions, but there’s always a point at which a certain OS won’t run on newer hardware. Now [Jubadub] has pushed one of those a little further than Apple intended, by persuading classic Mac System 7 to run on a G4.

System 7 was the OS your Mac would have run some time in the mid ’90s, whether it was a later 68000 machine or a first-gen PowerMac. In its day it gave Windows 3.x and even 95 a run for their money, but it relied on an older Mac ROM architecture than the one found on a G4. The hack here lies in leaked ROMS, hidden backwards compatibility, and an unreleased but preserved System 7 version originally designed for the ’90s Mac clone programme axed by Steve Jobs.  It’s not perfect, but they achieved the impossible.

As to why, it seems there’s a significant amount of software that needs 7 to run, something mirrored in the non-Mac retrocomputing world. Even this hack isn’t the most surprising System 7 one we’ve seen recently, as an example someone even made a version for x86 machines.


Thumbnail Image Art: Apple PowerMac G4 by baku13, CC BY-SA 3.0

Hackaday Podcast Episode 347: Breaking Kindles, Baby’s First Synth, And Barcodes!

This week, Hackaday’s Elliot Williams and Kristina Panos met up over coffee to bring you the latest news, mystery sound, and of course, a big bunch of hacks from the previous seven days or so.

On What’s That Sound, Kristina got sort of close, but of course failed spectacularly. Will you fare better and perhaps win a Hackaday Podcast t-shirt? Mayhap you will.

After that, it’s on to the hacks and such, beginning with an interesting tack to take with a flat-Earther that involves two gyroscopes.  And we take a look at the design requirements when it comes to building synths for three-year-olds.

Then we discuss several awesome hacks such as a vehicle retrofit to add physical heated seat controls, an assistive radio that speaks the frequencies, and an acoustic radiometer build. Finally, we look at the joys of hacking an old Kindle, and get a handle on disappearing door handles.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in DRM-free MP3 and savor at your leisure.

Continue reading “Hackaday Podcast Episode 347: Breaking Kindles, Baby’s First Synth, And Barcodes!”

Hackaday Podcast Episode 346: Melting Metal In The Microwave, Unlocking Car Brakes And Washing Machines, And A Series Of Tubes

Wait, what? Is it time for the podcast again? Seems like only yesterday that Dan joined Elliot for the weekly rundown of the choicest hacks for the last 1/52 of a year. but here we are. We had quite a bit of news to talk about, including the winners of the Component Abuse Challenge — warning, some components were actually abused for this challenge. They’re also a trillion pages deep over at the Internet Archive, a milestone that seems worth celebrating.

As for projects, both of us kicked things off with “Right to repair”-adjacent topics, first with a washing machine that gave up its secrets with IR and then with a car that refused to let its owner fix the brakes. We heated things up with a microwave foundry capable of melting cast iron — watch your toes! — and looked at a tiny ESP32 dev board with ludicrously small components. We saw surveyors go to war, watched a Lego sorting machine go through its paces, and learned about radar by spinning up a sonar set from first principles.

Finally, we wrapped things up with another Al Williams signature “Can’t Miss Articles” section, with his deep dive into the fun hackers can have with the now-deprecated US penny, and his nostalgic look at pneumatic tube systems.

Download this 100% GMO-free MP3.

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