Blu-ray Won, But At What Cost?

July 16, 2025 by John Elliot V 73 Comments

Over on their substack [ObsoleteSony] has a new article: The Last Disc: How Blu-ray Won the War but Lost the Future.

In this article the author takes us through the history of Blu-ray media and how under Sony’s stewardship it successfully defeated the competing format of the time, HD DVD. Sony started behind the eight ball but through some deft maneuvering managed to come out on top. Perhaps the most significant contributing factor was the inclusion of Blu-ray drives in the PlayStation 3.

The person leading the Blu-ray initiative for Sony was Masanobu Yamamoto, whose legacy was the compact disc. What was needed was a personal media format which could deliver for high-definition 1080p video. As the DVD format did not have the storage capacity required, new formats needed to be developed. The enabling technology for both Blu-ray and HD DVD media was the blue laser as it allowed for more compact encoding.

Sony’s Blu-ray format became the dominating format for high-definition personal media…just as physical media died.

Thanks to [Stephen Walters] for writing in about this one.

2025 One Hertz Challenge: Ham Radio Foxhunt Transmitter

July 13, 2025 by John Elliot V 9 Comments

[Jim Matthews] submitted his Ham Radio foxhunt transmitter project for the 2025 One Hertz Challenge.

This is a clever Spartan build. In order to create a radio beacon for use in a “fox hunt” [Jim] combined a SR-T300 walkie talkie module with a phototransistor and oscillating LED circuit. The phototransistor and oscillating LED are secured face-to-face inside heat shrink tubing which isolates them from ambient light. When the LED flashes on the phototransistor powers the radio which transmits a tone in the UHF band.

A fox hunt is a game played by radio enthusiasts in which players use radio signals to triangulate and find a hidden beacon. [Jim]’s circuit is the beacon, and when it’s powered by a three volt CR2032 battery, it transmits a strong signal over several hundred yards at 433.5 MHz, within the amateur radio UHF band.

If you’re interested in radio beacons you might like to read about the WSPR beacon.

Picture of front and back of thumb drive enclosure

Jcorp Nomad: ESP32-S3 Offline Media Server In A Thumbdrive

July 13, 2025 by John Elliot V 27 Comments

[Jackson Studner] wrote in to let us know about his ESP32-based media server: Jcorp Nomad.

This project uses a ESP32-S3 to create a WiFi hotspot you can connect to from your devices. The hotspot is a captive portal which directs the user to a web-interface comprised of static HTML assets which are in situ with the various media on an attached SD card formatted with a FAT32 file system. The static HTML assets are generated by the media.py Python 3 script when the ESP32 boots.

This project exists because the typical Raspberry Pi media server costs more than an ESP32 does. The ESP32 is smaller too, and demands less power.

According to [Jackson] this ESP32-based solution can support at least four concurrent viewers. The captive portal is implemented with DNS and HTTP services from the ESP32. The firmware is an Arduino project that integrates a bunch of libraries to provide the necessary services. The Jcorp Nomad media template supports Books (in pdf files), Music (in mp3 files), and Movies and Shows (in mp4 files). Also there is a convention for including JPEG files which can represent media in the user-interface.

And the icing on the cake? The project files include STL files so you can 3D print an enclosure. All in all, a very nice hack.

An Induction Lamp Made On The Same Principle As Ordinary Fluorescent Lamp

July 11, 2025 by John Elliot V 23 Comments

Over on YouTube, [Technology Connections] has a new video: Induction lamps: fluorescent lighting’s final form.

This video is about a wireless fluorescent light which uses induction to transfer power from the electrical system into the lamp. As this lamp doesn’t require wiring it is not prone to “sputtering” as typical fluorescent lights are, thus improving the working life by an order of magnitude. As explained in the video sputtering is the process where the electrodes in a typical fluorescent lamp lose their material over time until they lose their ability to emit electrons at all.

This particular lamp has a power rating of 200 W and light output of 16,000 lumens, which is quite good. But the truly remarkable thing about this type of lighting is its service life. As the lamp is simply a phosphor-coated tube filled with argon gas and a pellet of mercury amalgam it has a theoretically unlimited lifespan. Or let’s call it 23 years.

Given that the service life is so good, why don’t we see induction lamps everywhere? The answer is that the electronics to support them are very expensive, and these days LED lighting has trounced every lighting technology that we’ve ever made in terms of energy efficiency, quality of light, and so on. So induction lamps are obsolete before they ever had their day. Still pretty interesting technology though!

Continue reading “An Induction Lamp Made On The Same Principle As Ordinary Fluorescent Lamp” →

Photo showing the wire-wrapped version and PCB version of MyCPU side-by-side.

This Homebrew CPU Got Its Start In The 1990s

July 11, 2025 by John Elliot V 4 Comments

[Sylvain Fortin] recently wrote in to tell us about his Homebrew CPU Project, and the story behind this one is truly remarkable.

He began working on this toy CPU back in 1994, over thirty years ago. After learning about the 74LS181 ALU in college he decided to build his own CPU. He made considerable progress back in the 90s and then shelved the project until the pandemic hit when he picked it back up again and started adding some new features. A little later on, a board house approached him with an offer to cover the production cost if he’d like to redo the wire-wrapped project on a PCB. The resulting KiCad files are in the GitHub repository for anyone who wants to play along at home.

The ALU on [Sylvain]’s CPU is a 1-bit ALU which he describes as essentially a selectable gate: OR, XOR, AND, NOT. It requires more clock steps to compute something like an addition, but, he tells us, it’s much more challenging and interesting to manage at the microcode level. On his project page you will find various support software written in C#, such as an op-code assembler and a microcode assembler, among other things.

For debugging [Sylvain] started out with das blinkin LEDs but found them too limiting in short order. He was able to upgrade to a 136 channel Agilent 1670G Benchtop Logic Analyzer which he was fortunate to score for cheap on eBay. You can tell this thing is old from the floppy drive on the front panel but it is rocking 136 channels which is seriously OP.

The PCB version is a great improvement but we were interested in the initial wire-wrapped version too. We asked [Sylvain] for photos of the wire-wrapping and he obliged. There’s just something awesome about a wire-wrapped project, don’t you think? If you’re interested in wire-wrapping check out Wire Wrap 101.

Using an SMD capacitor as a clip for flash media on a circuit board.

SMD Capacitor Doubles As Cheap SD Card Latch

July 4, 2025 by John Elliot V 42 Comments

Here’s a clever hack. Simple, elegant, and eminently cost-effective: using an SMD capacitor to hold your flash media in place!

This is a hack that can pretty much be summed up with just the image at the top of the page — a carefully placed SMD capacitor soldered to a routed tab makes for an extremely cost effective locking mechanism for the nearby SD card slot. There’s just enough flexibility to easily move the capacitor when its time to insert or eject your media.

It’s worth noting that the capacitor in this example doesn’t even appear to be electrically connected to anything. But there’s also no reason you couldn’t position one of the capacitors in your existing bill of materials (BOM). This form of mechanical support will be much cheaper than special purpose clips or mounts. Not a big deal for low-volume projects, but if you’re going high-volume this is definitely something to keep in mind.

If you’re just getting started with SMD capacitors then one of the first things to learn is how to solder them. Also, if you’re hoping to salvage them then try to look for newer equipment which is more likely to have SMD components than through-hole. If you’re planning to use your capacitors for… “capacitance” (how quaint), you can start by learning the basics. And if you want to know everything you can learn about the history of capacitors, too.

Thanks to [JohnU] for writing in to let us know about this one. Have your own natty hacks? Let us know on the tipsline!

Back To The Future, 40 Years Old, Looks Like The Past

July 3, 2025 by John Elliot V 81 Comments

Great Scott! If my calculations are correct, when this baby hits 88 miles per hour, you’re gonna see some serious shit. — Doc Brown

On this day, forty years ago, July 3rd, 1985 the movie Back to the Future was released. While not as fundamental as Hackers or realistic as Sneakers, this movie worked its way into our pantheon. We thought it would be appropriate to commemorate this element of hacker culture on this day, its forty year anniversary.

If you just never got around to watching it, or if it has been a few decades since you did, then you might not recall that the movie is set in two periods. It opens in 1985 and then goes back to 1955. Most of the movie is set in 1955 with Marty trying to get back to 1985 — “back to the future”. The movie celebrates the advanced technology and fashions of 1985 and is all about how silly the technology and fashions of 1955 are as compared with the advancements of 1985. But now it’s the far future, the year 2025, and we thought we might take a look at some of the technology that was enchanting in 1985 but that turned out to be obsolete in “the future”, forty years on. Continue reading “Back To The Future, 40 Years Old, Looks Like The Past” →