When The UK’s Telephone Network Went Digital With System X

July 24, 2025 by Maya Posch 24 Comments

The switch from analog telephone exchanges to a purely digital network meant a revolution in just about any way imaginable. Gone were the bulky physical switches and associated system limitations. In the UK this change happened in the early 1980s, with what the Post Office Telecommunications (later British Telecom) and associated companies called System X. Along with the system’s rollout, promotional videos like this 1983 one were meant to educate the public and likely any investors on what a smashing idea the whole system was.

Although for the average person in the UK the introduction of the new digital telephone network probably didn’t mean a major change beyond a few new features like group calls, the same wasn’t true for the network operator whose exchanges and networks got much smaller and more efficient, as explained in the video. To this day System X remains the backbone of the telephone network in the UK.

To get an idea of the immense scale of the old analog system, this 1982 video (also embedded below) shows the system as it existed before System X began to replace it. The latter part of the video provides significant detail of System X and its implementation at the time, although when this video was produced much of the system was still being developed.

Thanks to [James Bowman] for the tip.

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The Death Of Industrial Design And The Era Of Dull Electronics

July 23, 2025 by Maya Posch 191 Comments

It’s often said that what’s inside matters more than one’s looks, but it’s hard to argue that a product’s looks and its physical user experience are what makes it instantly recognizable. When you think of something like a Walkman, an iPod music player, a desktop computer, a car or a TV, the first thing that comes to mind is the way that it looks along with its user interface. This is the domain of industrial design, where circuit boards, mechanisms, displays and buttons are put into a shell that ultimately defines what users see and experience.

Thus industrial design is perhaps the most important aspect of product development as far as the user is concerned, right along with the feature list. It’s also no secret that marketing departments love to lean into the styling and ergonomics of a product. In light of this it is very disconcerting that the past years industrial design for consumer electronics in particular seems to have wilted and is now practically on the verge of death.

Devices like cellphones and TVs are now mostly flat plastic-and-glass rectangles with no distinguishing features. Laptops and PCs are identified either by being flat, small, having RGB lighting, or a combination of these. At the same time buttons and other physical user interface elements are vanishing along with prominent styling, leaving us in a world of basic geometric shapes and flat, evenly colored surfaces. Exactly how did we get to this point, and what does this mean for our own hardware projects?

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Annealing In Space: How NASA Saved JunoCam In Orbit Around Jupiter

July 23, 2025 by Maya Posch 16 Comments

The Juno spacecraft was launched towards Jupiter in August of 2011 as part of the New Frontiers series of spacecraft, on what would originally have been a 7-year mission, including a nearly 5 year cruise to the planet. After a mission extension, it’s currently orbiting Jupiter, allowing for many more years of scientific data to be gathered using its instruments. One of these instruments is the JunoCam (JCM), a visible light camera and telescope. Unfortunately the harsh radiation environment around Jupiter had led many to believe that this camera would fail before long. Now it seems that NASA engineers have successfully tested a fix.

Location of the Juno spacecraft's science instruments. (Credit: NASA) — Location of the Juno spacecraft’s science instruments.

Although the radiation damage to JCM was obvious a few dozen orbits in – and well past its original mission’s 34 orbits – the big question was exactly what was being damaged by the radiation, and whether something could be done to circumvent or fix it. The good news was that the image sensor itself was fine, but one of the voltage regulators in JCM’s power supply was having a bad time. This led the engineers to try annealing the affected part by cranking up one of the JCM’s heaters to a balmy 25°C, well above what it normally is kept at.

This desperate step seemed to work, with massively improved image quality on the following orbits, but soon the images began to degrade again. Before an approach to Jupiter’s moon Io, the engineers thus tried it again but this time cranked the JCM’s heater up to eleven and crossed their fingers. Surprisingly this fixed the issue over the course of a week, until the JCM seems as good as new. Now the engineers are trying their luck with Juno‘s other instruments as well, with it potentially providing a blueprint for extending the life of spacecraft in general.

Thanks to [Mark Stevens] for the tip.

Nylon-Like TPU Filament: Testing CC3D’s 72D TPU

July 22, 2025 by Maya Posch 8 Comments

Another entry in the world of interesting FDM filaments comes courtesy of CC3D with their 72D TPU filament, with [Dr. Igor Gaspar] putting it to the test in his recent video. The use of the Shore hardness D scale rather than the typical A scale is a strong indication that something is different about this TPU. The manufacturer claims ‘nylon-like’ performance, which should give this TPU filament much more hardness and resistance to abrasion. The questions are whether this filament lives up to these promises, and whether it is at all fun to print with.

The CC3D 72D TPU filament used to print a bicycle's handlebar. (Credit: My Tech Fun, YouTube) — The CC3D 72D TPU filament used to print a bicycle’s handlebar grips. (Credit: My Tech Fun, YouTube)

TPU is of course highly hydrophilic, so keeping the filament away from moisture is essential. Printing temperature is listed on the spool as 225 – 245°C, and the filament is very bendable but not stretchable. For the testing a Bambu Lab X-1 Carbon was used, with the filament directly loaded from the filament dryer. After an overnight print session resulted in spaghetti due to warping, it was found that generic TPU settings at 240ºC with some more nylon-specific tweaks seemed to give the best results, with other FDM printers also working well that way.

The comparison was against Bambu Lab’s 68D TPU for AMS. Most noticeable is that the 72D TPU easily suffers permanent deformation, while being much more wear resistant than e.g. PLA. That said, it does indeed seem to perform more like polyamide filaments, making it perhaps an interesting alternative there. Although there’s some confusion about whether this TPU filament has polyamide added to it, it seems to be pure TPU, just like the Bambu Lab 68D filament.

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Power Grid Stability: From Generators To Reactive Power

July 22, 2025 by Maya Posch 41 Comments

It hasn’t been that long since humans figured out how to create power grids that integrated multiple generators and consumers. Ever since AC won the battle of the currents, grid operators have had to deal with the issues that come with using AC instead of the far less complex DC. Instead of simply targeting a constant voltage, generators have to synchronize with the frequency of the alternating current as it cycles between positive and negative current many times per second.

Complicating matters further, the transmission lines between generators and consumers, along with any kind of transmission equipment on the lines, add their own inductive, capacitive, and resistive properties to the system before the effects of consumers are even tallied up. The result of this are phase shifts between voltage and current that have to be managed by controlling the reactive power, lest frequency oscillations and voltage swings result in a complete grid blackout.

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Testing Your Knowledge Of JavaScript’s Date Class

July 21, 2025 by Maya Posch 18 Comments

JavaScript is everywhere these days, even outside the browser. Everyone knows that this is because JavaScript is the best programming language, which was carefully assembled by computer experts and absolutely not monkeyed together in five days by some bloke at Netscape in the 90s. Nowhere becomes this more apparent than in aspects like JavaScript’s brilliantly designed Date class, which astounds people to this day with its elegant handling of JavaScript’s powerful type system. This is proudly demonstrated by the JS Date quiz by [Samwho].

Recently [Brodie Robertson] decided to bask in the absolute glory that is this aspect of JavaScript, working his way through the quiz’s 28 questions as his mind gradually began to crumble at the sheer majesty of this class’ elegance and subtle genius. Every answer made both logical and intuitive sense, and left [Brodie] gobsmacked at the sheer realization that such a language was designed by mere humans.

After such a humbling experience, it would only seem right to introduce the new JS convert to the book JavaScript: The Good Parts, to fully prepare them for their new career as a full-stack JS developer.

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A Lockpicking Robot That Can Sense The Pins

July 21, 2025 by Maya Posch 15 Comments

Having a robot that can quickly and unsupervised pick any lock with the skills of a professional human lockpicker has been a dream for many years. A major issue with lockpicking robots is however the lack of any sensing of the pins – or equivalent – as the pick works its magic inside. One approach to try and solve this was attempted by the [Sparks and Code] channel on YouTube, who built a robot that uses thin wires in a hollow key, load cells and servos to imitate the experience of a human lockpicker working their way through a pin-tumbler style lock.

Although the experience was mostly a frustrating series of setbacks and failures, it does show an interesting approach to sensing the resistance from the pin stack in each channel. The goal with picking a pin-tumbler lock is to determine when the pin is bound where it can rotate, and to sense any false gates from security pins that may also be in the pin stack. This is not an easy puzzle to solve, and is probably why most lockpicking robots end up just brute-forcing all possible combinations.

Perhaps that using a more traditional turner and pick style approach here – with one or more loadcells on the pick and turner- or a design inspired by the very effective Lishi decoding tools would be more effective here. Regardless, the idea of making lockpicking robots more sensitive is a good one, albeit a tough nut to crack. The jobs of YouTube-based lockpicking enthusiasts are still safe from the robots, for now.

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