This Relay Computer Has Magnetic Tape Storage

June 11, 2025 by Jenny List 9 Comments

Magnetic tape storage is something many of us will associate with 8-bit microcomputers or 1960s mainframe computers, but it still has a place in the modern data center for long-term backups. It’s likely not to be the first storage tech that would spring to mind when considering a relay computer, but that’s just what [DiPDoT] has done by giving his machine tape storage.

We like this hack, in particular because it’s synchronous. Where the cassette storage of old just had the data stream, this one uses both channels of a stereo cassette deck, one for clock and the other data. It’s encoded as a sequence of tones, which are amplified at playback (by a tube amp, of course) to drive a rectifier which fires the relay.

On the record side the tones are made by an Arduino, something which we fully understand but at the same time can’t help wondering whether something electromechanical could be used instead. Either way, it works well enough to fill a relay shift register with each byte, which can then be transferred to the memory. It’s detailed in a series of videos, the first of which we’ve paced below the break.

If you want more cassette tape goodness, while this may be the slowest, someone else is making a much faster cassette interface. Continue reading “This Relay Computer Has Magnetic Tape Storage” →

Back To The Future Lunchbox Cyberdeck

June 10, 2025 by John Elliot V 4 Comments

Our hacker [Valve Child] wrote in to let us know about his Back to the Future lunchbox cyberdeck.

Great Scott! This is so awesome. We’re not sure what we should say, or where we should begin. A lot of you wouldn’t have been there, on July 3rd, 1985, nearly forty years ago. But we were there. Oh yes, we were there. On that day the movie Back to the Future was released, along with the hit song from its soundtrack: Huey Lewis & The News – The Power Of Love.

Continue reading “Back To The Future Lunchbox Cyberdeck” →

Using A Videocard As A Computer Enclosure

June 10, 2025 by Maya Posch 9 Comments

The CherryTree-modded card next to the original RTX 2070 GPU. (Credit: Gamers Nexus)

In the olden days of the 1990s and early 2000s, PCs were big and videocards were small-ish add-in boards that blended in with other ISA, PCI and AGP cards. These days, however, videocards are big and computers are increasingly smaller. That’s why US-based CherryTree Computers did what everyone has been joking about, and installed a PC inside a GPU, with [Gamers Nexus] having the honors of poking at the creatively titled GeeFarce 5027POS Micro Computer.

As CherryTree describes it on their website, this one-off build was the result of a joke about how GPUs nowadays are more expensive than the rest of the PC combined. Thus they did what any reasonable person would do and put an Asus NUC 13 with a 13th gen Core i7, 64 GB of and 2 TB of NVMe storage inside an (already dead) Asus Aorus RTX 2070 GPU.

In the [Gamers Nexus] video we can see that it’s definitely a quick-and-dirty build, with plenty of heatshrink and wires running everywhere in addition to the chopped off original heatsink. That said, from a few meter away it still looks like a GPU, can be installed like a GPU (but the PCIe connector does nothing) and is in the end a NUC PC inside a GPU shell that you can put a couple of inside a PC case.

Presumably the next project we’ll see in this vein will see a full-blown x86 system grafted inside a still functioning GPU, which would truly make the ‘install the PC inside the GPU’ meme a reality.

Continue reading “Using A Videocard As A Computer Enclosure” →

Wireless Power Makes For Cable-Free Desk

June 8, 2025 by Tyler August 33 Comments

Some people hate cables with a passion; others are agnostic and prefer cabled peripherals to having to stop and charge their mouse. [Matt] from DIYPerks has the best of both worlds with this wireless-powered, no-cable desk setup.

The secret is embedded within the plywood desk: an evaluation kit from Etherdyne Technologies, Inc consisting of a 100 W RF power supply and its associated power antenna looping around the desktop edge. The mechanism is similar to the inductive charging often seen on phones nowadays, but at higher frequency and larger scale, enabling power to be transmitted several feet (at least a meter) above the desktop.

The range is impressive (this isn’t the maximum), but the efficiency is not advertised.

The kit from ETI contained several PCB-coil receivers, which [Matt] built into a number of devices, including a lamp, heated cup, microphone, speakers, his mouse, keyboard, and even a custom base to run his monitor, which really shows the power these things can pull.

The microphone is a non-Bluetooth RF unit lovingly modified to studio quality, at least as far as we can tell on laptop speakers through YouTube’s compression. The speakers use a pair of Bluetooth modules to negotiate stereo sound while staying in sync. And before you ask “what about signal for the monitor?”– we have to inform you that was taken care of too, via a wireless HDMI dongle. Check it out in the video below.

Of course the elephant in the room here is power usage — there’s a 10 W base draw, and probably a big hit to efficiency vs cabled-everything– but we figure he gets partway to a pass on that by using a Frameworks mainboard instead desktop hardware. Indeed, a full analysis might show that the transmission efficiency of this system is no worse than the power to charge/discharge inefficiencies in a more conventional battery powered wireless setup.

While no wires is pretty clean, we’re not sure this beats the totally-hidden-in-the-desk PC [Matt] built last year in terms of minimalist aesthetic. That Frameworks mainboard also likely lacks the power of his triple-screen luggable, but this was still an entertaining build.

Continue reading “Wireless Power Makes For Cable-Free Desk” →

Invisible PC Doubles As Heated Seat

May 28, 2025 by Tyler August 20 Comments

Some people really want a minimalist setup for their computing. In spite of his potentially worrisome housing situation, this was a priority for the man behind [Basically Homeless]: clean lines on the desk. Where does the PC go? You could get an all-in-one, sure, but those use laptop hardware and he wanted the good stuff. So he decided to hide the PC in the one place no one would ever think to look: inside his chair. (Youtube video, embedded below.)

This chair has very respectable specs: a Ryzen 7 9800XD, 64GB of ram and a RTX 4060 GPU, but you’d never know it. The secret is using 50 mm aluminum standoffs between the wooden base of the seat and the chair hardware to create room for low-profile everything. (The GPU is obviously lying sideways and connected with a PCIe riser cable, but even still, it needed a low-profile GPU.) This assemblage is further hidden 3D printed case that makes the fancy chair donated from [Basically Homeless]’s sponsor look basically stock, except for the cables coming out of it. It’s a very niche project, but if you happen to have the right chair, he does provide STLs on the free tier of his Patreon.

This is the first time we’ve seen a chair PC, but desk PCs are something we’ve covered more than once, so there’s obviously a demand to hide the electronics. It remains to be seen if hiding a PC in a chair will catch on, but if nothing else [Basically Homeless] will have a nice heated seat for winter. To bring this project to the next level of minimalism, we might suggest chording keyboards in the armrests, and perhaps a VR headset instead of a monitor.

Continue reading “Invisible PC Doubles As Heated Seat” →

A console is shown displaying a system’s startup information, followed by “Booting from Hard Disk …”, “Hello World!” in a green font, and “The keyboard is working!”

A Forth OS In 46 Bytes

May 27, 2025 by Aaron Beckendorf 27 Comments

It’s not often that we can include an operating system in a Hackaday article, but here’s the full 46-byte source of [Philippe Brochard]’s 10biForthOS in 8086 opcodes:

50b8 8e00 31d8 e8ff 0017 003c 0575 00ea
5000 3c00 7401 eb02 e8ee 0005 0588 eb47
b8e6 0200 d231 14cd e480 7580 c3f4

Admittedly, this is quite a minimal operating system. It’s written for the Intel 8086, and consists of a Forth implementation with only two instructions: compile (1) and execute (0). It can receive commands over a serial connection or from a keyboard. This allows a host computer to load more complex software onto it, one byte at a time. In particular, [Philippe] provides instructions for loading more advanced compilers, such as subleq-eForth for a more complete Forth implementation, or SectorC for C programming. He’s also written a 217-byte port of the OS to Linux Intel x64.

[Philippe] doesn’t take a strong stance on whether this should technically qualify as a Forth implementation, given that the base implementation lacks stacks, dictionaries, and the ability to define words. However, it does have an outer and inner interpreter, the ability to compile and execute code, and most importantly, “the simplicity and hacky feeling of Forth.”

[Philippe] writes that this masterpiece of minimalism continues the tradition of the minimal Forth implementations we’ve covered before. We’ve even seen Forth run on an Arduino.

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

May 26, 2025 by Tyler August 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.