British wartime periscope on a workbench

British Wartime Periscope: A Peek Into The Past

April 22, 2025 by 4 Comments

We all know periscopes serve for observation where there’s no direct line-of-sight, but did you know they can allow you to peer through history?  That’s what [msylvain59] documented when he picked up a British military night vision periscope, snagged from a German surplus shop for just 49 euros. Despite its Cold War vintage and questionable condition, the unit begged for a teardown.

The periscope is a 15-kilo beast: industrial metal, cryptic shutter controls, and twin optics that haven’t seen action since flares were fashionable. One photo amplifier tube flickers to greenish life, the other’s deader than a disco ball in 1993. With no documentation, unclear symbols, and adjustment dials from hell, the teardown feels more like deciphering a British MoD fever dream than a Sunday project. And of course, everything’s imperial.

Despite corrosion, mysterious bulbs, and non-functional shutters, [msylvian59] uncovers a fascinating mix of precision engineering and Cold War paranoia. There’s a thrill in tracing light paths through mil-spec lenses (the number of graticules seen that are etched on the optics) and wondering what secrets they once guarded. This relic might not see well anymore, but it sure makes us look deeper. Let us know your thoughts in the comments or share your unusual wartime relics below.

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Game Boy PCB Assembled With Low-Cost Tools

April 22, 2025 by 13 Comments

As computers have gotten smaller and less expensive over the years, so have their components. While many of us got our start in the age of through-hole PCBs, this size reduction has led to more and more projects that need the use of surface-mount components and their unique set of tools. These tools tend to be more elaborate than what would be needed for through-hole construction but [Tobi] has a new project that goes into some details about how to build surface-mount projects without breaking the bank.

The project here is interesting in its own right, too: a display module upgrade for the classic Game Boy based on an RP2350B microprocessor. To get all of the components onto a PCB that actually fits into the original case, though, surface-mount is required. For that [Tobi] is using a small USB-powered hotplate to reflow the solder, a Pinecil, and a healthy amount of flux. The hotplate is good enough for a small PCB like this, and any solder bridges can be quickly cleaned up with some extra flux and a quick pass with a soldering iron.

The build goes into a lot of detail about how a process like this works, so if you’ve been hesitant to start working with surface mount components this might be a good introduction. Not only that, but we also appreciate the restoration of the retro video game handheld complete with some new features that doesn’t disturb the original look of the console. One of the other benefits of using the RP2350 for this build is that it’s a lot simpler than using an FPGA, but there are perks to taking the more complicated route as well.

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Why Physical Media Deserved To Die

April 22, 2025 by 135 Comments

Over the course of more than a decade, physical media has gradually vanished from public view. Once computers had an optical drive except for ultrabooks, but these days computer cases that even support an internal optical drive are rare. Rather than manuals and drivers included on a data CD you now get a QR code for an online download. In the home, DVD and Blu-ray (BD) players have given way to smart TVs with integrated content streaming apps for various services. Music and kin are enjoyed via smart speakers and smart phones that stream audio content from online services. Even books are now commonly read on screens rather than printed on paper.

With these changes, stores selling physical media have mostly shuttered, with much audiovisual and software content no longer pressed on discs or printed. This situation might lead one to believe that the end of physical media is nigh, but the contradiction here comes in the form of a strong revival of primarily what used to be considered firmly obsolete physical media formats. While CD, DVD and BD sales are plummeting off a cliff, vinyl records, cassette tapes and even media like 8-track tapes are undergoing a resurgence, in a process that feels hard to explain.

How big is this revival, truly? Are people tired of digital restrictions management (DRM), high service fees and/or content in their playlists getting vanished or altered? Perhaps it is out of a sense of (faux) nostalgia?

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The central solenoid taking shape in the ITER assembly hall.

What’s Sixty Feet Across And Superconducting?

April 22, 2025 by 54 Comments

What’s sixty feet (18.29 meters for the rest of the world) across and superconducting? The International Thermonuclear Experimental Reactor (ITER), and probably not much else.

The last parts of the central solenoid assembly have finally made their way to France from the United States, making both a milestone in the slow development of the world’s largest tokamak, and a reminder that despite the current international turmoil, we really can work together, even if we can’t agree on the units to do it in.

A cutaway diagram of the ITER tokamak showing the central solenoid
The central solenoid is in the “doughnut hole” of the tokamak in this cutaway diagram. Image: US ITER.

The central solenoid is 4.13 m across (that’s 13′ 7″ for burger enthusiasts) sits at the hole of the “doughnut” of the toroidal reactor. It is made up of six modules, each weighing 110 t (the weight of 44 Ford F-150 pickup trucks), stacked to a total height of 59 ft (that’s 18 m, if you prefer). Four of the six modules have been installed on-site, and the other two will be in place by the end of this year.

Each module was produced ITER by US, using superconducting material produced by ITER Japan, before being shipped for installation at the main ITER site in France — all to build a reactor based on a design from the Soviet Union. It doesn’t get much more international than this!

This magnet is, well, central to the functioning of a tokamak. Indeed, the presence of a central solenoid is one of the defining features of this type, compared to other toroidal rectors (like the earlier stellarator or spheromak). The central solenoid provides a strong magnetic field (in ITER, 13.1 T) that is key to confining and stabilizing the plasma in a tokamak, and inducing the 15 MA current that keeps the plasma going.

When it is eventually finished (now scheduled for initial operations in 2035) ITER aims to produce 500 MW of thermal power from 50 MW of input heating power via a deuterium-tritium fusion reaction. You can follow all news about the project here.

While a tokamak isn’t likely something you can hack together in your back yard, there’s always the Farnsworth Fusor, which you can even built to fit on your desk.

BGA soldering

Making A One-Of-A-Kind Lime2 SBC

April 22, 2025 by 5 Comments

Upgrading RAM on most computers is often quite a straightforward task: look up the supported modules, purchase them, push a couple of levers, remove the old, and install the new. However, this project submitted by [Mads Chr. Olesen] is anything but a simple.

In this project, he sets out to double the RAM on a Olimex A20-OLinuXino-LIME2 single-board computer. The Lime2 came with 1 GB of RAM soldered to the board, but he knew the A20 processor could support more and wondered if simply swapping RAM chips could double the capacity. He documents the process of selecting the candidate RAM chip for the swap and walks us through how U-Boot determines the amount of memory present in the system.

While your desktop likely has RAM on removable sticks, the RAM here is soldered to the board. Swapping the chip required learning a new skill: BGA soldering, a non-trivial technique to master. Initially, the soldering didn’t go as planned, requiring extra steps to resolve issues. After reworking the soldering, he successfully installed both new chips. The moment of truth arrived—he booted up the LIME2, and it worked! He now owns the only LIME2 with 2 GB of RAM.

Be sure to check out some other BGA soldering projects we’ve featured over the years.

PoX: Super-Fast Graphene-Based Flash Memory

April 21, 2025 by 15 Comments

Recently a team at Fudan University claimed to have developed a picosecond-level Flash memory device (called ‘PoX’) that has an access time of a mere 400 picoseconds. This is significantly faster than the millisecond level access times of NAND Flash memory, and more in the ballpark of DRAM, while still being non-volatile. Details on the device technology were published in Nature.

In the paper by [Yutong Xing] et al. they describe the memory device as using a two-dimensional Dirac graphene-channel Flash memory structure, with hot carrier injection for both electron and hole injection, meaning that it is capable of both writing and erasing. Dirac graphene refers to the unusual electron transport properties of typical monolayer graphene sheets.

Demonstrated was a write speed of 400 picoseconds, non-volatile storage and a 5.5 × 106 cycle endurance with a programming voltage of 5 V. It are the unique properties of a Dirac material like graphene that allow these writes to occur significantly faster than in a typical silicon transistor device.

What is still unknown is how well this technology scales, its power usage, durability and manufacturability.

Jolly Wrencher Down To The Micron

April 21, 2025 by 6 Comments

RepRap was the origin of pushing hobby 3D printing boundaries, and here we see a RepRap scaled down to the smallest detail. [Vik Olliver] over at the RepRap blog has been working on getting a printer working printing down to the level of micron accuracy.

The printer is constructed using 3D printed flexures similar to the OpenFlexure microscope. Two flexures create the XYZ movement required for the tiny movements needed for micron level printing. While still in the stages of printing simple objects, the microscopic scale of printing is incredible.

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