Mysterious Files PH

If you asked us to build you a KVM last week, we’d likely have reached for a Raspberry Pi. Now, thanks to [JonathanRowny], we’d seriously consider an ESP32-P4, because his IP KVM seems pretty capable.

He’s using the P4 hardware to its fullest, getting the supported 1080p graphics, and doing so in an interesting way– he’s got a commercial adapter board to try and translate HDMI signals to the camera input on his dev board. Conveniently enough, it’s the same ribbon-cable pinout as the RPi, which is not guaranteed by the CSI standard. Writing a driver to take that signal proved the hardest part– aside from the usual chip revision confusion that plagues this chip– and we can’t help but wonder if the client on the other side of the KVM-IP link might have an easier time doing the image processing that was required for a good image. Regardless, he’s got the code as it is now up on GitHub under the Apache license. 

As of this this writing, there’s no audio, and ironically for an ESP32 project networking is wired-only– but much more importantly, there is no security. So it’s a work in progress, but great to see the P4 in the wild doing something other than emulation. Not that we haven’t seen the P4 at work before–the Tanmatsu handheld also makes use of Expressif’s most powerful chip for a handy little terminal. Between the KVM and the handhelds, we cannot help but wonder how many of the projects that were once the provenance of a Pi will get squeezed into these overpowered microcontrollers. Sure, they can’t even match the original Pi in horsepower, never mind a modern Pi5, but how many times have you seen a Linux SBC seriously under-taxed in a project like this?

If you’re swapping Pi for P4– or doing anything else interesting– please let us know on the tips line.

For some reason there’s heated debate around the topic of whether high current carrying wiring ought to use crimped or soldered connections, even though the industry standard is to crimp everything. As a practical demonstration of why this is the case, [Will Prowse] set up a test involving a rig capable of dispensing a few hundred amps through both a crimped and a soldered copper cable.

Prior to making things go spicy, [Will] made sure to check the resistance of the two cables, noting that the soldered version had significantly lower resistance than the crimped connectors. This could be one metric that proponents of soldered connectors can point to as a benefit.

Of course, the main benefit of crimping is that you create a cold weld if crimped properly, which is a sold-state welding process that effectively blends two metal surfaces together. This is also why wire wrap is generally considered to be so very reliable, as it creates a gas-free, solid connection that does not rely on a softer, dissimilar material like solder to hold things together. Of note here is also that the cold weld process tends to continue for a while, so this kind of connection is likely to get better over time.

In the subsequent testing this difference is demonstrated quite well, especially when both cables are subjected to the sort of mechanical abuse that would be expected in an installation, such as vibrations and direct impacts. Here the soldered connections quickly begin to fail, resulting in one soldered connector even unsoldering itself due to heat development. Ultimately cold welding is simply superior over relying on a flimsy and capricious interface of intermetallic compounds.

Hackaday’s Elliot Williams and Al Williams were in a retro mood this week. There was a new ‘486 computer, a new mechanical TV, and a USB stick with a magnetic personality. Can you watch YouTube on a Game Boy? Maybe.

For the can’t miss articles, this week, Elliot and Al reflected on the awkward phase of 3D printers when they transformed from being expensive commercial machines, to where they are now. Meanwhile, Al was interested in how airplanes know how fast they are going. Along the way, there were musical hacks, precision machine tools, and a quantum 8 ball.

Check out the links if you want to follow along, and as always, tell us what you think about this episode in the comments! Or write or record something for our mailbag segment.

Direct download in authentic retro DRM-free MP3.

Episode 376 Show Notes:

Mailbag:

• Thanks to Tom Lyons for calling [Elliot] out on the weather in the Garden State. Why don’t you write or record something? Send us your questions or comments, and you might hear them in a future show.

What’s that Sound:

• Congrats to [PostalPreacher] for correctly guessing last week’s sound. Be sure to drop in next week for your chance to win an exclusive Hackaday Podcast T-shirt.

Interesting Hacks of the Week:

• Hackaday Europe 2026 – Building A Retro PC From Scratch
• Building A Micrometer-Level Displacement Sensor With 3D Printed Parts
• Hack Improves Cheap Speed Controllers
  • Running Four Brushless Motors With A Single Pi Pico
  • Motors Make The Best Knobs With SimpleFOC
• Watch YouTube On A Game Boy Color With A Special Cartridge
  • Dumping Game Boy Cartridges Via The Link Cable Port
  • GB Interceptor Enables Live Screen Capture From Game Boy
  • The Ultimate Game Boy Talk
• Mechanical TV, Without The Benefit Of New Parts

Quick Hacks:

• Elliot’s Picks:
  • Reflective LCD Slabtop Terminal Runs Homebrewed Solar OS
  • Fixing An Elgato Cam Link’s USB Current Draw Issue
  • GPU-Accelerated Autorouter Handles Monstrous PCB Designs
  • Piano Escapement Migrates To Drum Kit
  • Hard Drive Speakers Crank Out Classic Demo
  • Bite Into Strange Sounds With NOISFERATU
• Al’s Picks:
  • RF Hacking A Ceiling Fan Via The Remote
  • Accurate Split-Flap Display Can Be 3D Printed
  • A Quantum Magic 8-Ball

Can’t-Miss Articles:

• The Teenage Angst Of 3D Printing: Solidoodle, Printrbot, And Bridges
• How Airspeed Sensors Work
  • Tech In Plain Sight: Speedometers
  • Encyclopedia of Sensors

When we think of 1960s synthesizers it’s usual to imagine instruments with vast arrays of controls and patch cables for configuring their many filters, oscillators, and other parameters. They created the templates for much of what we know today as electronic music.

In all the rush to look at full-blown synths though, it’s easy to forget their more mundane cousin, the electric organ. These instruments graced many a ’60s suburban home or church hall, and [Emma Repairs] has an interesting one. It’s a Philips Philicordia, and it’s sent us here at Hackaday down one of those rabbit holes when we should really be writing.

The instrument is a relatively straightforward single voice electric organ on the outside, but under the hood it’s a different matter. In an age when the transistor was revolutionizing electronic music, the folks in Eindhoven designed this one using tubes. There are a set of conventional enough tubes performing the role of amplifiers and oscillators, but the real party piece of this unit is the array of neon tube dividers. A neon bulb can be used as a switching element, and in those days when affordable digital logic chips were several years away, it made sense to use them in digital circuits.

The inside of the Philicordia is a feast of vintage Philips parts that will be instantly familiar to anyone who’s worked on Western European electronics of this era. The exterior design of the instrument screams understated early-1960s cool, and after she’s introduced it you can hear her playing it in the video below. Further down that rabbit hole we found that one of these instruments provided the distinctive organ sound on Chris Montez’s 1962 hit Let’s Dance, so they weren’t all uncool.

There are plenty of radios you can buy that pick up MW and SW bands if that’s what you’re into. Or, you can follow [mircemk]’s example, and whip one up yourself instead.

The build employs an ESP32 as the brains of the operation. It’s hooked up to a rotary encoder and a small colour TFT screen, which displays an old-school style tuning dial for choosing the desired frequency. This setup is paired with an Si5351—a capable clock generator chip that can deliver just about any frequency from <8KHz up to 150+ MHz on command. There’s naturally a bunch of supporting analog hardware for the radio end of things, plus a NE612 mixer IC and a PAM8403 class D audio amplifier board, hooked up to a small 0.25W speaker for audio output. [mircemk] has set up the rig to act as a simple radio set, or, with the flick of a switch, it can be configured for SDR use with an attached computer.

It’s a handsome build, and one that likely proves a pleasant way to browse the MW and SW bands on a rainy afternoon. We’ve looked at other hardware in this category before, too. Video after the break.

This is one of those projects that was both inspired and made possible by the absolute embarrassment of dev boards available to the modern hacker. In this case, the dev board was the M5Stack PaperS3, which as the name implies combines an ESP32-S3 with an e-ink panel. [Wenting Zhang] picked one up and was immediately inspired to try and make an e-ink Game Boy.

The M5Stack PaperS3 made this project possible by exposing the display with row/column control — parallel, some would call it, as opposed to the usual serial interface of SPI. That allowed [Wenting] to work some of the same e-ink magic he perfected on his Modos monitors to allow partial refresh at up to 60 Hz. That the ESP32-S3 is capable of emulating a Game Boy while driving the screen should surprise no one, since it can emulate an MSX while outputting VGA or even Windows 95 on a 386. In this case, he’s basing the actual Game Boy emulation on Crank Boy.

Of course the e-ink screen on the M5Stack is far larger and has a much higher resolution than what the Game Boy shipped with, which lets him implement touch controls and scale the image up 3X so he can fake a couple of shades of grayscale while actually outputting black and white. Even better, if he was actually playing this thing on the regular, once the high-refresh portion of the screen starts to wear out, he can flip the orientation and keep gaming on the virtually-unrefreshed control portion of the screen — doubling the lifetime of the system, something many of you raised as a concern when we last looked at a his e-ink monitor project.

The only real shortcoming of this hack is the sound. With one-bit beeps coming out of the M5Stack buzzer, it’s got nothing on Nintendo’s hardware. Of course, that’s partially down to using the hardware as-is. With the addition of an I2S sound chip like the one used in the MOD player project we featured recently, you’d just need to squeeze out enough processor cycles to make this sound as good as it looks.

It’s a fact of life when starting a computer, that booting into whatever operating system you use will take a while. Mine takes somewhere around 30 seconds, and yours probably does too. There has always been the promise of something faster just around the corner, but somehow the OS just keeps getting a little bigger. Perhaps the only computer with a disk based operating system I have ever owned which bucked this trend was a Commodore Amiga, and that machine’s booting speed was achieved by keeping most of its OS in a ROM. The subject of today’s Daily Drivers takes the idea of a long boot time and shreds it, leaving an experience more akin to that Amiga of old. It’s called KolibriOS, it’s small enough to run from a floppy disk if you want it to, it’s lightweight, and fast as lightning. It achieves this feat by being written entirely in assembly language, and it exists as a free fork of the earlier MenuetOS which moved to a proprietary licence in its 64 bit version. I downloaded the ISO file, and gave it a spin.

The minimum system requirements for KolibriOS are meagre, 1Mb of disk space, 8Mb of RAM, and a 586-class 32-bit processor. On a 2020s ThinkPad it boots in the proverbial blink of an eye, and drops immediately into a GUI desktop. It has the slightly pixelated look of a 1990s machine, there’s none of the anti-aliasing we’re used to today going on there. Installed software ranges from a set of games, emulators, graphics editors and viewers, internet software including the Webview and Netsurf web browsers, and assembly software development.

The immediate impression is of a mature and useful operating system, without any crashes or blue screens, and with applications that load on a dime. Unfortunately though, despite all the competence I can’t call it a Daily Driver by my definition of being able to write for Hackaday, because the web browser doesn’t support https. Immediately the majority of the modern Internet is off-limits, including this site. This changes the parameters of my review and I can no longer proceed as I normally would, but it doesn’t end it. Something this polished deserves a while to play around.

Diving into the command prompt gives a feeling somewhere between a UNIX style OS and DOS, as the commands are UNIX-style but their output feels more DOS-like. Navigating around the disk I’m immediately struck by how small the executables are due to their being written in assembly language. The only exceptions are those applications ported from outside such as Netsurf or DOSBox, which is hardly surprising.

Back in the 1990s there was a single-floppy demo of the QNX operating system that packed the OS, a GUI, and a reasonable web browser for the day. At the time it was mind-blowing to see so much in such a small space, and I am reminded of that QNX demo when I use KolibriOS. This is evidently a useful OS, and I am only sad that it doesn’t support the one thing that would make it useful for my purposes. If you have an older machine I can see it would make a great emulator platform though, and since one of the emulators gives you DOS it’s likely it could also run a lot of useful things from that OS. It will never offer the flexibility on a 32-bit laptop that a Linux distro such as SliTaz can, but on the other hand that low system requirement means it could make a much older 32-bit machine into something useful. If you’ve got some ancient hardware and fancy something new, give it a try!