A radio with a white front grate and wood edges sits on a grey surface. Next to the radio are small white disks with colorful edges reminicient of microdisc-sized records. A yellow-ringed disk sits on the radio. The handwritten title says, "Summer of 2011; Holidays in Barcelona"

Spotify Player Brings Back Physical Media

December 24, 2022 by Navarre Bartz 21 Comments

Digital music has made keeping all your tunes with you a lot more convenient, but have we lost something with dematerialization? [Jordi Parra] felt that there was something lacking with the digital music experience and designed a Spotify player with a tactile interface.

Specific playlists are selected via small RFID tags that look like a cross between a MiniDisc and a vinyl record. As this is a prototype, an Arduino reads the RFID tag, but needs a computer to actually play the Spotify playlist. Future iterations could include an integrated speaker and run libspotify to create a self-contained device.

While there is still work to do for a fully seamless experience, we love the details in the industrial design of this project. Clean simple lines and a combination of wood and more modern materials make this feel like a timeless piece of tech. Definitely check out the full photo gallery including shots of the really impressive packaging.

Want more digital music with a tactile interface? Check out this MP3 Player Shelf or a Simple Internet Radio Transplant.

Blinky Project Is 6502s All The Way Down

December 24, 2022 by Zoe Skyforest 19 Comments

Virtually any platform you might find yourself programming on has some simple method of running a delay. [Joey Shepard] got rather creative on a recent project, though, relying on a rather silly nesting method that we’re calling 6502s All The Way Down.

The project in question was a simple PCB that was shaped like a robot, with blinking LED eyes. Typically, you’d simply reach for the usual sleep() or delay() function to control the blink rate, but [Joey] went off-piste for this one. Instead, the PIC32 on the board runs a 6502 emulator written in MIPS assembly. This emulated 6502 is then charged with running a further 6502 emulator coded in 6502 assembly, and so on, until there’s 6502 emulators running six-deep on the humble microcontroller. The innermost emulator runs a simple program that blinks the LED eyes in a simple loop. With the overhead of running six emulators, though, the eyes only blink at a rate of roughly once every two seconds.

It’s an amusing and complicated way to write a blink program, and we applaud [Joey] for going to all that trouble. We imagine it was a great way to learn about programming the PIC32 as well as emulation in general. Meanwhile, if you’re working on your own emulator feats, be sure to let us know!

A Hacker’s Christmas Story

December 24, 2022 by Elliot Williams 11 Comments

Twas the night before Christmas, and because I decided to make everyone’s presents myself this year, I’m still working like mad to get everything done before the big deadline. Why do I do this to myself? Well, partly because I enjoy the process.

My wife had this idea that we can make the older folks some fun decorative blinky things, and picked some motives. My son then drew them out on paper, and I scanned those drawings in and traced them over in CAD. We then cut the shapes out of wood on the CNC router, which turned out to be incredibly successful. (Now that I’ve done it, I wouldn’t be surprised if all of those “quirky” decorative objects that the Swedish flat-packers sell aren’t initially sketched out by third graders.)

Then my son painted them, and it’s my job to insert the twinkling. I bought some of those three-wire “fairy lights” for the purpose, and they’re really fun to hack on. They’re like WS2812s, only instead of using four pins and shifting the data downstream, they’re on a bus, each with a hard-coded address – they know where they are in the string and each LED only listens for the Nth set of 24 bits. This means sending 200 color codes just to light up the 4 LEDs in Aunt Micki’s decorative tree, but so be it.

Last stop, and still to do as of the 23rd, route out some kind of wooden battery case, wedge in the LiPo and the charging circuits, and solder on an on/off switch. It’s down to the last minute, but isn’t that always the way?

Definitely would have been easier just to order something online. But is that the spirit of giving? No! The DIY way brings the family together, gets me some quality time with the CNC machine, and tones up my FreeCAD skills. My son even looked over my shoulder as we were coding some of the LED animations. And nothing says Christmas like hand-coded blinkies.

Happy Holidays, y’all!

How To Restore A Musical Amiga

December 24, 2022 by Bryan Cockfield 21 Comments

Despite the huge strides in computing power and functionality that have been achieved in the past few decades, there are still some things that older computers can do which are basically impossible on modern machines. This doesn’t just include the ability to use older hardware that’s now obsolete, either, although that is certainly a perk. In this two-part restoration of an Amiga 500, [Jeremy] shows us some of these features like the ability to directly modify the audio capabilities of this retro machine.

The restoration starts by fixing some damage and cleaning up the rest of the machine so it could be powered up for the first time in 30 years. Since it was in fairly good shape he then started on the fun part, which was working with this computer’s audio capabilities. It includes a number of amplifiers and filters in hardware that can be switched on or off, so he rebuilt these with new op-amps and added some new controls so that while he is using his MIDI software he can easily change how it sounds. He also restored the floppy disk drives and cleaned up the yellowing on the plastic parts to improve the overall appearance, as well as some other general improvements.

These old Amigas have a lot going for them, but since [Jeremy] is a musician he mostly focused on bringing back some of the musical functionality of his childhood computer, although he did build up a lot of extra features in this machine as well. These types of audio circuits are not something found in modern computers, though, so to get a similar sound without using original hardware you’ll need to build something like this NES audio processing unit programmed in Verilog.

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CoreFreq Gives Peek At CPU Performance Info On Linux

December 24, 2022 by Zoe Skyforest 9 Comments

The CPU is the part of the computer that makes everything else tick. While GPUs have increasingly become a key part of overall system performance, we still find ourselves wanting to know how our CPU is doing. CoreFreq is a Linux tool that aims to tell you everything you want to know about your modern 64-bit CPU.

The tool relies on a kernel module, and is coded primarily in C, with some assembly code used to measure performance as accurately as possible. It’s capable of reporting everything from core frequencies to details on hyper-threading and turbo boost operation. Other performance reports include information on instructions per cycle or instructions per second, and of course, all the thermal monitoring data you could ask for. It all runs in the terminal, which helps keep overheads low.

The hardcore among us can build it from source, available on GitHub, though it’s reportedly available in package form, and as a live CD, too. We could imagine data captured from CoreFreq could be used for some fun performance visualizations, too. If you’ve been whipping up your own nifty command-line tools, be sure to drop us a line!

Three purple OshPark boards and a white bread board all attached using a number of jumper wires on a grey cutting mat.

An (Almost) Single-Chip Apple IIe

December 23, 2022 by Navarre Bartz 10 Comments

The Apple II is one of the most iconic microcomputers, and [James Lewis] decided to use the Mega-II “Apple IIe on a chip” from an Apple IIgs to build a tiny Apple IIe.

While there was an Apple II compatibility card using the related Gemini chip, it was initially unclear whether the Mega-II could even work outside of an Apple IIgs given the lack of documentation for either Apple II SOC. [Lewis] did finally get the Mega-II to boot after a great deal of effort in debugging and design. The system is built with three boards: the Mega-II and RAM board, a CPU board with a 65C02, and a video out board.

To simplify routing, the boards are all four layer PCBs. Unfortunately, the chips needed to make this system, especially the Mega-II, aren’t available on their own and must be harvested from an existing IIgs. [Lewis] took care to make sure any desoldering or other part removal was done in a way that it could be reversed. If you want to see all the nitty gritty details, check out his GitHub for the project.

If you want another 6502-based computer in a tiny package, why not try this one built on Perf+ boards?

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Chainless “Digital Drive” Bikes Use Electric Power Transmission Instead

December 23, 2022 by Zoe Skyforest 140 Comments

We’re all familiar with how regular bikes work, with the pedals connected to the rear wheel via a simple chain drive. This setup is lightweight, cheap, and highly efficient. It’s not the only way to drive a bike though, and there’s plenty of buzz around the concept of “digital drive” bikes.

These drivetrains rely on electrical methods to transfer power in place of mechanical. The pedals are used to turn an electric generator, with power then sent to an electric motor which drives the rear wheel. The concept may sound overly complicated, but it does offer some benefits. The generator can change its operation to keep the rider pedalling at their most efficient, consistent rate. There would also be no chain to fall off, get snagged on clothing, or require regular maintenance.

It would make integrating regenerative braking possible, too, allowing the bike to harvest energy when going downhill too. This could be achieved with a storage battery or supercapacitor. As a bonus, it would be very easy to integrate power assist for the rider when tackling tough hills, for example. The lack of requirement for direct mechanical power transfer also means that there’s far more flexibility to design a bike with interesting geometry.

Such drive systems do give up some efficiency, however. All the power conversions between mechanical and electrical energy mean that a “digital drive” would likely only be 58% efficient. This compares poorly to the roughly 95% efficiency of power transfer in regular mechanically-driven bikes. There’s also a weight penalty, too.

Presnetly, there’s only one “digital drive” bike on the market – known as the Mando Footloose. It’s a swooping, folding, futuristic design, that has some feel issues when it comes to pedalling. And, given the added complexity and expense of these systems, it’s unlikely regular bikes or e-bikes are going away any time soon. Regardless, it’s fun to think about the potential for other drivetrain concepts to change the way we cycle. Video after the break.

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