Disarming A Nuke… Twice

Since the tail end of World War II, humanity has struggled to deal with its newfound ability to harness the tremendous energy in the nucleus of the atom. Of course there have been some positive developments like nuclear power which can produce tremendous amounts of electricity without the greenhouse gas emissions of fossil fuels. But largely humanity decided to build a tremendous nuclear weapons arsenal instead, which has not only cause general consternation worldwide but caused specific problems for one scientist in particular.

[Steve Weintz] takes us through the tale of [Dr. John C. Clark] who was working with the Atomic Energy Commission in the United States and found himself first at a misfire of a nuclear weapons test in the early 1950s. As the person in charge of the explosive device, it was his responsibility to safely disarm the weapon after it failed to detonate. He would find himself again in this position a year later when a second nuclear device sat on the test pad after the command to detonate it was given. Armed with only a hacksaw and some test equipment he was eventually able to disarm both devices safely.

One note for how treacherous this work actually was, outside of the obvious: although there were safety devices on the bombs to ensure the nuclear explosion would only occur under specific situations, there were also high explosives on the bomb that might have exploded even without triggering the nuclear explosion following it. Nuclear bombs and nuclear power plants aren’t the only things that the atomic age ushered in, though. There have been some other unique developments as well, like the nuclear gardens of the mid 1900s.

A 100-Year-Old Electronic Musical Instrument Brought Back To Life

In the early years of electrification, when electricity was beginning to shape the modern world, this new technology was being put to use in many more places than turning motors and providing lighting. Some things we can see as obvious missteps like electrified corsets marketed as health tonics or x-ray treatments for eye strain, but others ended up being fascinating bits of technology with interesting uses, many of which have been largely forgotten since. This 100-year-old musical instrument is squarely in the latter category, and this build brings the sound of it back to life.

The instrument was called the Luminaphone and was originally built by [Harry Grindell Matthews]. Of course, this was an age before transistors and many other things we take for grated, so it has some quirks that we might not otherwise expect from a musical instrument. The device generated sound by shining a series of lights through a perforated rotating disc at a selenium cell. The selenium cell was an early photoresistor, generating current corresponding to the amount of light falling on it. A keyboard activated different lights, shining on areas of the disc with different numbers of holes, causing differing sounds to be produced by the instrument.

The recreation was built by [Nick Bild] and uses a laser diode as a stand-in for the rotating disc, but since it can be modulated in a similar way the idea is that the photodiode used as a receiver would generate a similar sound. The recreation sounds a bit like a video game from the 8-bit era, but with no recordings or original Luminaphones surviving to the present day we may never know how accurate it is. There are some other electronic instruments still around today, though, and plenty of ways of DIY-ing their sound like this project which recreates the tonewheels of the classic Hammond organ.

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Hand Truck Turned Into Motorcycle

For those motorcyclists looking to get a classic American-style cruiser, often the go-to brand is Harley-Davidson. However, these bikes not only have reputations for being stuck in the past, both in terms of design and culture, but they also tend to be extremely expensive—not only upfront, but in maintenance as well. If you want the style without all of that baggage, you might want to try out something like this custom motorcycle which not only looks the part, it reduces those costs by being built around a hand truck.

By the end of the project, though, the hand truck does not retain much of its original form or function. [Garage Avenger] has cut and welded it essentially into a custom frame for the diminutive motorcycle, while retaining much of its original look and feel. Keeping up with the costs savings aspect of this project, the four-stroke engine was free, although it did take some wrenching to get it running and integrated into the frame. A custom axle, a front end from another bike, a gas tank from an online retailer (that needed re-welding), and some wiring finishes out the build.

With a fresh paint job to match the original color of the hand truck, it’s off to the track. Of course it doesn’t have quite the performance of most street legal motorcycles, including some quirks with the handling and braking, but for the trails around [Garage Avenger]’s home it’s certainly a fun transportation mode he can add to his repertoire. If this is your first time seeing one of his projects, be sure to check out his other work including this drifting shopping cart and this turbine-powered sled.

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A RISC-V Operating System Instruction Manual

To some, an operating system is a burden or waste of resources, like those working on embedded systems and other low-power applications. To others it’s necessary, abstracting away hardware so that higher-level programming can be done. For most people it’s perhaps not thought of at all. But for a few, the operating system is the most interesting piece of software running on a computer and if you’d like to investigate what makes this often overlooked aspect of computer science interesting, take a look at this course on operating systems from Cornell University.

The operating system itself is called Earth and Grass Operating System because it splits the functionality of the operating system into three separate parts. The Earth layer involves dealing with hardware, the Grass layer involves hardware-independent aspects, and a third application layer implements other key operating system features. It’s built for a RISC-V processor, since that instruction set is completely open source and transparent about what it’s doing. It’s also incredibly small, coming in at around 2000 lines of code. The course covers nine areas, with the first six being core operating system functions and the remaining three covering more advanced operating system concepts.

For understanding the intricacies and sometimes mysterious ways that operating systems work, a course like this can go a long way into unraveling those mysteries and developing a deeper understanding of how it brings the hardware to work for higher-level software. We actually featured this operating system two years ago, before this course was created, which covers this project for those who like to take a more self-directed approach, or simply want a lightweight OS for a RISC-V system.

Unreleased Amiga Hardware Plays MP3s

The MP3 file type has been around for so long, and is supported by essentially all modern media software and hardware, that it might be surprising to some to learn that it’s actually a proprietary format. Developed in the late 80s and early 90s, it rose to prominence during the Napster/Limewire era of the early 00s and became the de facto standard for digital music, but not all computers in these eras could play this filetype. This includes the Amigas of the early 90s, with one rare exception: this unreleased successor to the A3000 with a DSP chip, which now also has the software to play back these digital tunes.

The AA3000, developed as a prototype by Commodore, was never released to the general public. Unlike the original A3000 this one would have included a digital signal processing chip from AT&T called the DSP3210 which would have greatly enhanced its audio capabilities. A few prototype boards did make it out into the hands of the public, and the retrocomputing scene has used them to develop replicas of these rare machines. [Wrangler] used one to then develop the software needed for the MPEG layer 2 and 3 decoder using this extra hardware, since the original Amiga 3000 was not powerful enough on its own to play these files back.

If you want to follow along with the community still developing for this platform there’s a form post with some more detail for this specific build (although you may need to translate from German). [Wrangler] additionally points out that there are some limitations with this implementation as well, so you likely won’t get Winamp-level performance with this system, but for the Amiga fans out there it’s an excellent expansion of this computer’s capabilities nonetheless.

Thanks to [Andy] for the tip!

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NES Zapper Becomes Telephone

Although there was a time in the 80s (and early 90s for fans of the SuperScope) where light guns were immensely popular, with games like DuckHunt cultural touchstones, their time in the video game world has largely come to an end. We might occasionally pick up a Zapper for the NES and play this classic out of nostalgia, but plenty of people are looking for other things that these unique video game controllers can do instead. [Nick] has turned one of his old NES peripherals into a wireless phone.

The way the original Zapper worked was by looking for a certain pattern of pixels that displayed for a fraction of a second whenever the trigger was pulled. Bypassing the anti-cheat mechanism that looks only for qualities of light coming from CRT screens of the day effectively turns the light gun into an analog light sensor which is used for receiving the audio from the phone’s base station via a laser. Of course there were no microphones present within the original hardware so one is added, wiring its output to another laser that communicates to the base station. With the light gun pointed directly at this base station, audio is communicated back and forth by varying the strengths of these small lasers and listening to them on the other end with photodiodes.

[Nick] does point out that this isn’t a great phone, largely because it needs to be pointed exactly at the right spot to work at all, although we do agree that it’s an interesting project that demonstrates what the original hardware could do with a few of its limitations removed. There are a few other ways of bringing these devices into the modern world, with one of our favorites being this laser pointer with additional hardware from a Wiimote that could also function as a mouse.

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Trashed Sound System Lives To Rock Another Day

Plenty of consumer goods, from passenger vehicles to toys to electronics, get tossed out prematurely for all kinds of reasons. Repairable damage, market trends, planned obsolescence, and bad design can all lead to an early sunset on something that might still have some useful life in it. This was certainly the case for a sound system that [Bill] found — despite a set of good speakers, the poor design of the hardware combined with some damage was enough for the owner to toss it. But [Bill] took up the challenge to get it back in working order again.

Inside the DIY control unit.

The main problem with this unit is that of design. It relies on a remote control to turn it on and operate everything, and if that breaks or is lost, the entire unit won’t even power on. Tracing the remote back to the control board reveals a 15-pin connector, and some other audio sleuths online have a few ways of using this port to control the system without the remote.

[Bill] found a few mistakes that needed to be corrected, and was eventually able to get an ESP8266 (and eventually an ESP32) to control the unit thanks largely to the fact that it communicates using a slightly modified I2C protocol.

There were a few pieces of physical damage to correct, too. First, the AC power cable had been cut off which was simple enough to replace, but [Bill] also found that a power connector inside the unit was loose as well. With that taken care of he has a perfectly functional and remarkably inexpensive sound system ready for movies or music. There are some other options available for getting a set of speakers blasting tunes again as well, like building the amplifier for them from scratch from the get-go.