Mechanical TV, Without The Benefit Of New Parts

June 29, 2026 by Jenny List 9 Comments

There are many experimenters who have had a go at a mechanical television, and though there are a few challenges, it’s a relatively straightforward project in 2026. A hundred years ago though it was still beyond the cutting edge of technology, and that’s where [Paul Kocyla] is placing his build. It’s a mechanical TV system, using only parts that would have been available in the 1920s. The project isn’t finished yet, but we suggest following along for some fascinating insights into developments in early electronics.

As it stands he has a wooden chassis, a period power supply and amplifier, a synchronous motor, and of course the Nipkow disk that makes it all possible. The electronics aren’t quite finished, and he’s yet to source a neon lamp. This last part may be particularly tricky, as there were specific flat-plate neon lamps made for this application. It’s interesting to find that the motor would synchronize to the grid frequency and would need to be restarted a few times for the frame to be in the right place.

His last posting contains a particularly interesting nugget of information for anyone using tubes. The amplifier carries a 120 Hz hum, something difficult to trace. The culprit is the early tubes with directly heated cathodes formed from the heaters themselves; they had such a low thermal mass that they would “blink” at 120 Hz if fed with AC. A set of period copper oxide rectifiers solve this by feeding DC to the heaters. There’s a YouTube series to follow, and we’ve placed the most recent one in which he fixes the power supply, below the break.

Back in January, we marked the hundredth anniversary of mechanical TV’s invention. Meanwhile, some of us have been known to experiment in this direction too.

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It’s Linux, On A Sega Megadrive

June 29, 2026 by Jenny List 14 Comments

If you were in the market for a games console in 1990, the chances are that the object of your desire was either a Super Nintendo with its 16-bit 6502 derivative, or the Sega Megadrive, sold as the Genesis in North America, with its Motorola 68000. Both machines featured impressive graphics and sound for their time, but they remain firmly in the 16-bit era. Which makes it a surprise to see LinuxMD. It’s Linux, for the Sega Megadrive, with the latest mainline kernel.

The Motorola 68000 series of chips was the first porting target for Linux, and is still maintained in 2026. This build runs from an SD card in a modern Megadrive storage peripheral, and is reported to run on the original hardware. The lowly 68000 in the Sega doesn’t have a memory management unit required for the full Linux experience, so what’s really running here is a kernel compiled with the -nommu option. That in itself is a feat, on this architecture. On it you get smolutils, a cut down coreutils, and that seems to be it.

We like this project, for pushing both console and kernel to the limit, even though we see that maybe it’s not the most practical Linux machine. Meanwhile though, this isn’t the only UNIX-like OS for this console.

Image: Evan-Amos, Public domain.

Make Your Own Loudspeaker From Scratch

June 28, 2026 by Jenny List 6 Comments

A loudspeaker is a vital component of every device that plays sound, but while its operation is simple, it’s a surprisingly difficult device to build. [Rvanderouderaa] has made an Instructables post showing a speaker design that it’s claimed, had an impedance that varies by volume (Dutch language, Google Translate link).

In all moving-coil speakers, a coil of wire is held in a radial magnetic field. To this is attached a cone, and when a current is passed through the coil the whole thing moves to create the sound. The tricky part of making one comes in making the cone itself, and in particular the suspension system that holds it in place while allowing it to move backwards and forwards. It’s normal for these components to be moulded from thick paper.

This design uses a 3D printed frame and cone, with the 3D printing providing excellent rigidity. The suspension system is a circular corrugated sheet, and it’s made in this case using papier-maché made from wet toilet paper, and a 3D printed mould. We particularly like this technique.

This is an impressive build, simply for having made a recognizable and working speaker in the first place. There’s no demo video so we have no idea how it sounds, but for us the point is more in the construction than the reproduction.

If speakers interest you, we’ve taken an in-depth look at them in the past.

A Standalone YouTube Streaming Rig

June 27, 2026 by Jenny List 1 Comment

YouTube streaming typically involves a camera with an HDMI output, a USB3 HDMI digitiser, and a suitably beefy PC to run it all. It’s quite a process, and for [Coreymillia], more complex than it needs to be. He’s come up with something simpler, a dedicated self-contained streaming rig using a Raspberry Pi 4.

As you might expect it uses the Raspberry Pi HQ camera at the optical end, but it’s the software surrounding it that transforms it from a mere camera into a streaming rig. There’s a web based user interface, but perhaps more interesting are the companion dashboard peripherals. A Raspberry Pi or an ESP32 Cheap Yellow Display can both serve as a small in-view dashboard and controller.

We know from experience that a stream can be a difficult thing to get right even with high-end hardware, and we’re interested to see this standalone device allowing , we hope, an easier way to do it. If you’re a streamer we’re guessing you’ll be taking a closer look. Even so, this is surprisingly, not the simplest Raspberry Pi based streaming device we’ve seen.

Requiem For Long Wave, As The BBC Goes Silent

June 27, 2026 by Jenny List 61 Comments

Something happened this morning which will have been unnoticed by many, but which for a certain breed of radio enthusiast marks the end of an era. The BBC stopped broadcasting Radio 4 on their 198 kHz Long Wave frequency, ending over a century of transmission in the band. For now the transmitter carries a recorded message telling listeners that the service has ended, but it’s expected that this will soon be turned off.

A pair of very large transmitting masts against a cloudy grey sky. — The main 198kHz BBC transmitter, at Droitwich. Bob Nienhuis, Public domain.

American readers may be unfamiliar with Long Wave as it’s a band not allocated in their region. Covering 153 to 279 kHz, it’s a relic from the earliest days of high-power broadcasting in the 1920s, used because of the enormous distances that could be covered with its lower frequencies. The main long wave transmitter for the BBC is at Droitwich, and its demise comes because there are no more spares for its high-power transmitter tubes. It joins many Medium Wave, or AM, as it is commonly known, stations in leaving the airwaves, as increased interference from switch mode electronics and the availability of higher quality alternatives took away their listeners. It’s fair to say that there will be few whose lives are inconvenienced by the switch-off in 2026, but it’s worth taking a moment to remember.

The first BBC Long Wave transmissions in the mid-1920s were on a 1600 metre wavelength, or 187.5 kHz. A series of international agreements saw them move to 193 kHz, and then 200 KHz or 1500 metres in 1934. They stayed on that frequency until another shift down 2 KHz to 198 kHz in 1988. They were atomic-controlled, and thus usable as a frequency standard. The programming started with station names redolent of their era, first the BBC National Service, then the Light Programme you’ll see on the dial in the header image, and finally the more modern-sounding Radio 4. A famous BBC programme tied to Long Wave is the Shipping Forecast, a weather bulletin for deep-sea fishermen which became cult listening on land and now features on FM and digital services too, and there’s even a probably-apocryphal tale that British nuclear submarine captains would once use its presence or absence to judge whether nuclear war had occurred.

In an Oxfordshire farmhouse not far short of fifty years ago, a young child who would later become a Hackaday writer heard a radio show like nothing before, which made an impression that continues to this day. The show was one of the earliest airings of the original Hitchhikers Guide To The Galaxy radio series, through a 1970s ITT radio tuned to BBC Radio 4 on (then) 200 kHz Long Wave. So long, Droitwich, and thanks for all the fish.

Make That Smart TV Into A Computer

June 25, 2026 by Jenny List 23 Comments

The smart TV is a fixture in most houses, variously an entertainment portal, corporate data gathering tool, or sometimes an outright spy. It’s a nice monitor with a computer built in, so can that computer be released to do something else? It’s a question [Xen’on] is answering, on an Android-based TV.

The guide is not too different from many others relating to Android phones, with a few quirks. An Android Debug Bridge (ADB) connection is established, root access is gained using Shizuku, and then it’s a case of installing a more conventional Linux front end with the Openbox window manager through Termux. There are some TV-specific things to do with handling power cycles, but the TV is now a usable Linux box.

It’s always good to see someone retrieve the Linux underneath a locked-down device, but the system spec tells the real story. By the looks of things this TV is a few years old as it had an Android version that’s a bit long in the tooth, and thus it also packs an aged version 4.x kernel. Couple that with a more seat-of-your-pants experience compared to a regular distro where many of the annoyances are taken care of, this isn’t an easy route to a trouble free desktop. Instead it has a lot of potential for making the TV what it was intend to be, an entertainment device. Merely one that gives much more software freedom.

Meanwhile, this isn’t the first Termux guide we’ve seen.

A BIOS For Your ESP32-C6

June 23, 2026 by Jenny List 24 Comments

An old-style PC BIOS served the function of a bootloader in loading the operating system kernel, and of an API in providing a set of standard system calls through which software could interact with the hardware. Though it as been long-ago superseded by operating system level calls and UEFI bootloaders, it was a simple and easy-to-understand firmware for the PCs of the day.

Microcontrollers usually don’t have anything quite like a BIOS because their software is more often compiled as-is without the need for one. But here’s [Rompass] who has bucked that trend, with a BIOS for the ESP32-C6.

Of course this isn’t the PC BIOS we all know, and you’ll not be running DOS on it. Instead it’s a subsystem that serves the purposes outlined above and provides an environment for dynamically loaded executables from RAM rather than an operating system kernel. The executables are compiled in the normal way for the ESP32, and can be loaded over the network if necessary.

We don’t know how popular a firmware like this one will become, but for us it’s symptomatic of how the line between a microcontroller and a microprocessor is becoming blurred. The next few years are going to continue this trend, as inexpensive microcontroller application processors such as the C6’s P4 bigger brother move into the mainstream.

Header image: Popolon, CC BY-SA 4.0.