Crowdsourcing SIGINT: Ham Radio At War

I often ask people: What’s the most important thing you need to have a successful fishing trip? I get a lot of different answers about bait, equipment, and boats. Some people tell me beer. But the best answer, in my opinion, is fish. Without fish, you are sure to come home empty-handed.

On a recent visit to Bletchley Park, I thought about this and how it relates to World War II codebreaking. All the computers and smart people in the world won’t help you decode messages if you don’t already have the messages. So while Alan Turing and the codebreakers at Bletchley are well-known, at least in our circles, fewer people know about Arkley View.

The problem was apparent to the British. The Axis powers were sending lots of radio traffic. It would take a literal army of radio operators to record it all. Colonel Adrian Simpson sent a report to the director of MI5 in 1938 explaining that the three listening stations were not enough. The proposal was to build a network of volunteers to handle radio traffic interception.

That was the start of the Radio Security Service (RSS), which started operating out of some unused cells at a prison in London. The volunteers? Experienced ham radio operators who used their own equipment, at first, with the particular goal of intercepting transmissions from enemy agents on home soil.

At the start of the war, ham operators had their transmitters impounded. However, they still had their receivers and, of course, could all read Morse code. Further, they were probably accustomed to pulling out Morse code messages under challenging radio conditions.

Over time, this volunteer army of hams would swell to about 1,500 members. The RSS also supplied some radio gear to help in the task. MI5 checked each potential member, and the local police would visit to ensure the applicant was trustworthy. Keep in mind that radio intercepts were also done by servicemen and women (especially women) although many of them were engaged in reporting on voice communication or military communications.

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Reconductoring: Building Tomorrow’s Grid Today

What happens when you build the largest machine in the world, but it’s still not big enough? That’s the situation the North American transmission system, the grid that connects power plants to substations and the distribution system, and which by some measures is the largest machine ever constructed, finds itself in right now. After more than a century of build-out, the towers and wires that stitch together a continent-sized grid aren’t up to the task they were designed for, and that’s a huge problem for a society with a seemingly insatiable need for more electricity.

There are plenty of reasons for this burgeoning demand, including the rapid growth of data centers to support AI and other cloud services and the move to wind and solar energy as the push to decarbonize the grid proceeds. The former introduces massive new loads to the grid with millions of hungry little GPUs, while the latter increases the supply side, as wind and solar plants are often located out of reach of existing transmission lines. Add in the anticipated expansion of the manufacturing base as industry seeks to re-home factories, and the scale of the potential problem only grows.

The bottom line to all this is that the grid needs to grow to support all this growth, and while there is often no other solution than building new transmission lines, that’s not always feasible. Even when it is, the process can take decades. What’s needed is a quick win, a way to increase the capacity of the existing infrastructure without having to build new lines from the ground up. That’s exactly what reconductoring promises, and the way it gets there presents some interesting engineering challenges and opportunities.

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Is The Atomic Outboard An Idea Whose Time Has Come?

Everyone these days wants to talk about Small Modular Reactors (SMRs) when it comes to nuclear power. The industry seems to have pinned its hopes for a ‘nuclear renaissance’ on the exciting new concept. Exciting as it may be, it is not exactly new: small reactors date back to the heyday of the atomic era. There were a few prototypes, and a lot more paper projects that are easy to sneer at today. One in particular caught our eye, in a write-up from Steve Wientz, that is described as an atomic outboard motor.

It started as an outgrowth from General Electric’s 1950s work on airborne nuclear reactors. GE’s proposal just screams “1950s” — a refractory, air-cooled reactor serving as the heat source for a large turboprop engine. Yes, complete with open-loop cooling. Those obviously didn’t fly (pun intended, as always) but to try and recoup some of their investment GE proposed a slew of applications for this small, reactor-driven gas turbine. Rather than continue to push the idea of connecting it to a turboprop and spew potentially-radioactive exhaust directly into the atmosphere, GE proposed podding up the reactor with a closed-cycle gas turbine into one small, hermetically sealed-module. Continue reading “Is The Atomic Outboard An Idea Whose Time Has Come?”

The Ongoing BcacheFS Filesystem Stability Controversy

In a saga that brings to mind the hype and incidents with ReiserFS, [SavvyNik] takes us through the latest data corruption bug report and developer updates regarding the BcacheFS filesystem in the Linux kernel. Based on the bcache (block cache) cache mechanism in the Linux kernel, its author [Kent Overstreet] developed it into what is now known as BcacheFS, with it being announced in 2015 and subsequently merged into the Linux kernel (6.7) in early 2024. As a modern copy-on-write (COW) filesystem along the lines of ZFS and btfs, it was supposed to compete directly with these filesystems.

Despite this, it has become clear that BcacheFS is rather unstable, with frequent and extensive patches being submitted to the point where [Linus Torvalds] in August of last year pushed back against it, as well as expressing regret for merging BcacheFS into mainline Linux. As covered in the video, [Kent] has pushed users reporting issues to upgrade to the latest Linux kernel to get critical fixes, which really reinforces the notion that BcacheFS is at best an experimental Alpha-level filesystem implementation and should probably not be used with important data or systems.

Although one can speculate on the reasons for BcacheFS spiraling out of control like this, ultimately if you want a reliable COW filesystem in Linux, you are best off using btrfs or ZFS. Of course, regardless of which filesystem you use, always make multiple backups, test them regularly and stay away from shiny new things on production systems.

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Information Density: Microfilm And Microfiche

Today, we think nothing of sticking thousands of pages of documents on a tiny SD card, or just pushing it out to some cloud service. But for decades, this wasn’t possible. Yet companies still generated huge piles of paper. What could be done? The short answer is: microfilm.

However, the long answer is quite a bit more complicated. Microfilm is, technically, a common case of the more generic microform. A microform is a photographically reduced document on film. A bunch of pages on a reel of film is microfilm. If it is on a flat card — usually the size of an index card — that’s microfiche. On top of that, there were a few other incidental formats. Aperture cards were computer punch cards with a bit of microfilm included. Microcards were like microfiche, but printed on cardboard instead of film.

In its heyday, people used specialized cameras, some made to read fanfold computer printer paper, to create microfilm. There were also computer output devices that could create microfilm directly.

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Feline Genetics And Why Orange Cats Are The Most Special

Recently, butlers to orange-colored cats got a bit of a shock when reading the news, as headlines began to call out their fuzzy feline friends as ‘freaks of nature’ and using similarly uncouth terms. Despite the name-calling, the actual reason for this flurry of feline fascination was more benign — with two teams of scientists independently figuring out the reason why some cats have fur that is orange. Tracking down the reason for this turned out to be far more complicated than assumed, with the fact that about 80% of orange cats are male being only the tip of the cat-shaped iceberg.

It was known to be an X chromosome-linked mutation, but rather than the fur coloring being affected directly, instead the mechanism was deduced to be a suppression of the black-brownish pigmentation (eumelanin) in favor of the orange coloration (pheomelanin). Finding the exact locus of the responsible ‘O gene’ (for orange) in the cat genome has been the challenge for years, which turned out to be a mutation related to the X-linked ARHGAP36 gene, whose altered expression results in the suppression of many melanogenesis genes.

Interestingly, this particular mutation appears to be of a singular origin that apparently persisted over millennia courtesy of the domestication of humans (H. sapiens) by Felis catus.

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Screens Of Death: From Diagnostic Aids To A Sad Emoji

There comes a moment in the life of any operating system when an unforeseen event will tragically cut its uptime short. Whether it’s a sloppily written driver, a bug in the handling of an edge case or just dumb luck, suddenly there is nothing more that the OS’ kernel can do to salvage the situation. With its last few cycles it can still gather some diagnostic information, attempt to write this to a log or memory dump and then output a supportive message to the screen to let the user know that the kernel really did try its best.

This on-screen message is called many things, from a kernel panic message on Linux to a Blue Screen of Death (BSOD) on Windows since Windows 95, to a more contemplative message on AmigaOS and BeOS/Haiku. Over the decades these Screens of Death (SoD) have changed considerably, from the highly informative screens of Windows NT to the simplified BSOD of Windows 8 onwards with its prominent sad emoji that has drawn a modicum of ridicule.

Now it seems that the Windows BSOD is about to change again, and may not even be blue any more. So what’s got a user to think about these changes? What were we ever supposed to get out of these special screens?

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