Reflective pool of the Court of the Myrtles, looking north towards the Comares Tower. (Credit: Tuxyso, Wikimedia)

Medieval Alhambra’s Pulser Pump And Other Aquatic Marvels

Recently the Practical Engineering YouTube channel featured a functional recreation of a pump design that is presumed by some to have been used to pump water up to the medieval Alhambra palace and its fortress, located in what is today Spain. This so-called pulser pump design is notable for not featuring any moving parts, but the water pump was just one of many fascinating engineering achievements that made the Alhambra a truly unique place before the ravages of time had their way with it.

Although the engineering works were said to still have been functional in the 18th century, this pumping system and many other elements that existed at the peak of its existence had already vanished by the 19th century for a number of reasons. During this century a Spanish engineering professor, Cáceres, tried to reconstruct the mechanism as best as he could based on the left-over descriptions, but sadly we’ll likely never know for certain that it is what existed there.

Similarly, the speculated time-based fountain in the Court of the Lions and other elements are now forever lost to time, but we have plenty of theories on how all of this worked in a pre-industrial era.

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Spy Tech: Conflicts Bring A New Number Station

If you know much about radios and espionage, you’ve probably encountered number stations. These are mysterious stations that read out groups of numbers or otherwise encoded messages to… well… someone. Most of the time, we don’t know who is receiving the messages. You’d be excused for thinking that this is an old technology. After all, satellite phones, the Internet, and a plethora of options now exist to allow the home base to send spies secret instructions. However, the current-day global conflict has seen at least one new number station appear, apparently associated with the United States and, presumably, targeting some recipients in Iran, according to priyom.org.

As you might expect, these stations don’t identify themselves, but the Enigma Control List names this one as V32. It broadcasts two two-hour blocks a day at 0200 UTC and a repeat at 1800 UTC. Each message starts with the Farsi word for “attention” followed by what is assumed to be some header information as two 5-digit groups. Then there is a set of 181 five-digit groups. Each message is padded out to take 20 minutes, and there are six messages in each transmission.

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Soviet CDs And CD Players Existed, And They Were Strange

Until the fall of the Soviet Union around 1990 you’d be forgiven as a proud Soviet citizen for thinking that the USSR’s technology was on par with the decadent West. After the Iron Curtain lifted it became however quite clear how outdated especially consumer electronics were in the USSR, with technologies like digital audio CDs and their players being one good point of comparison. In a recent video by a railways/retro tech YouTube channel we get a look at one of the earliest Soviet CD players.

A good overall summary of how CD technology slowly developed in the Soviet Union despite limitations can be found in this 2025 article by [Artur Netsvetaev]. Soviet technology was characterized mostly by glossy announcements and promises of ‘imminent’ serial production prior to a slow fading into obscurity. Soviet engineers had come up with the Luch-001 digital audio player in 1979, using glass discs. More prototypes followed, but with no means for mass-production and Soviet bureaucracy getting in the way, these efforts died during the 1980s.

During the 1980s CD players were produced in Soviet Estonia in small batches, using Philips internals to create the Estonia LP-010. Eventually sanctions on the USSR would strangle these efforts, however. Thus it wouldn’t be until 1991 that the Vega PKD-122 would become the first mass-produced CD player, with one example featured in this video.

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Retail Fail: The :CueCat Disaster

Digital Convergence Corporation is hardly a household name, and there’s a good reason for that. However, it raised about $185 million in investments around the year 2000 from companies such as Coca-Cola, Radio Shack, GE, E. W. Scripps, and the media giant Belo Corporation. So what did all these companies want, and why didn’t it catch on? If you are old enough, you might remember the :CueCat, but you probably thought it was Radio Shack’s disaster. They were simply investors.

The Big Idea

The :CueCat was a barcode scanner that, usually, plugged into a PC’s keyboard port (in those days, that was normally a PS/2 port). A special cable, often called a wedge, was like a Y-cable, allowing you to use your keyboard and the scanner on the same port. The scanner looked like a cat, of course.

However, the :CueCat was not just a generic barcode scanner. It was made to only scan “cues” which were to appear in catalogs, newspapers, and other publications. The idea was that you’d see something in an ad or a catalog, rush to your computer to scan the barcode, and be transported to the retailer’s website to learn more and complete the purchase.

The software could also listen using your sound card for special audio codes that would play on radio or TV commercials and then automatically pop up the associated webpage. So, a piece of software that was reading your keyboard, listening to your room audio at all times, and could inject keystrokes into your computer. What could go wrong?

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The Most Secure, Modern Computer Might Be A Mac

The Linux world is currently seeing an explosion in new users, thanks in large part to Microsoft turning its Windows operating system into the most intrusive piece of spyware in modern computing. For those who value privacy and security, Linux has long been the safe haven where there’s reasonable certainty that the operating system itself isn’t harvesting user data or otherwise snooping where it shouldn’t be. Yet even after solving the OS problem, a deeper issue remains: the hardware itself. Since around 2008, virtually every Intel and AMD processor has included coprocessors running closed-source code known as the Intel Management Engine (IME) or AMD Platform Security Processor (PSP).

M1 MacBook Air, now with more freedom

These components operate entirely outside the user’s and operating system’s control. They are given privileged access to memory, storage, and networking and can retain that access even when the CPU is not running, creating systemic vulnerabilities that cannot be fully mitigated by software alone. One practical approach to minimizing exposure to opaque management subsystems like the IME or PSP is to use platforms that do not use x86 hardware in the first place. Perhaps surprisingly, the ARM-based Apple M1 and M2 computers offer a compelling option, providing a more constrained and clearly defined trust model for Linux users who prioritize privacy and security.

Before getting into why Apple Silicon can be appealing for those with this concern, we first need to address the elephant in the room: Apple’s proprietary, closed-source operating system. Luckily, the Asahi Linux project has done most of the heavy lifting for those with certain Apple Silicon machines who want to go more open-source. In fact, Asahi is one of the easiest Linux installs to perform today even when compared to beginner-friendly distributions like Mint or Fedora, provided you are using fully supported M1 or M2 machines rather than attempting an install on newer, less-supported models. The installer runs as a script within macOS, eliminating the need to image a USB stick. Once the script is executed, the user simply follows the prompts, restarts the computer, and boots into the new Linux environment. Privacy-conscious users may also want to take a few optional steps, such as verifying the Asahi checksum and encrypting the installation with LUKS but these steps are not too challenging for experienced users. Continue reading “The Most Secure, Modern Computer Might Be A Mac”

From Zip To Nought: The Rise And Fall Of Iomega

If you were anywhere near a computer in the mid-to-late 1990s, you almost certainly encountered a Zip drive. That distinctive purple peripheral, with its satisfying clunk as you slotted in a cartridge, was as much a fixture of the era as beige tower cases and CRT monitors. Iomega, the company behind it, went from an obscure Utah outfit to a multi-billion-dollar darling of Wall Street in the span of about two years. And then, almost as quickly, it all fell apart.

The story of Iomega is one of genuine engineering innovation and the fickle nature of consumer technology. As with so many other juggernauts of its era, Iomega was eventually brought down by a new technology that simply wasn’t practical to counter.

The House That Bernoulli Built

Iomega was founded in Utah, in 1980, by Jerome Paul Johnson, David Bailey, and David Norton. The company soon developed a novel approach to removable magnetic storage based on the Bernoulli effect. The Bernoulli Box arrived in 1982, which was a drive relying on PET film disks spun at 1500 RPM inside a rigid, removable cartridge. The airflow generated by the spinning disk pulled the media down toward the read/write head thanks to the eponymous Bernoulli effect. While spinning, the disk would float a mere micron above the head surface on a cushion of air. If the power cut out or the drive otherwise failed, the disk simply floated away from the head rather than crashing into it—a boon over contemporary hard drives for which head crashes were a real risk. The Bernoulli Box made them essentially impossible. Continue reading “From Zip To Nought: The Rise And Fall Of Iomega”