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Hackaday Links: December 8, 2024

December 8, 2024 by 14 Comments

For some reason, we never tire of stories highlighting critical infrastructure that’s running outdated software, and all the better if it’s running on outdated hardware. So when we learned that part of the San Francisco transit system still runs on 5-1/4″ floppies, we sat up and took notice. The article is a bit stingy with the technical details, but the gist is that the Automatic Train Control System was installed in the Market Street subway station in 1998 and uses three floppy drives to load DOS and the associated custom software. If memory serves, MS-DOS as a standalone OS was pretty much done by about 1995 — Windows 95, right? — so the system was either obsolete before it was even installed, or the 1998 instance was an upgrade of an earlier system. Either way, the San Francisco Municipal Transportation Agency (SFMTA) says that the 1998 system due to be replaced originally had a 25-year lifespan, so they’re more or less on schedule. Replacement won’t be cheap, though; Hitachi Rail, the same outfit that builds systems that control things like the bullet train in Japan, is doing the job for the low, low price of $212 million.

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Retrotechtacular: The Deadly Shipmate

November 27, 2024 by 33 Comments

During World War II, shipboard life in the United States Navy was a gamble. No matter which theater of operations you found yourself in, the enemy was all around on land, sea, and air, ready to deliver a fatal blow and send your ship to the bottom. Fast forward a couple of decades and Navy life was just as hazardous but in a different way, as this Navy training film on the shipboard hazards of low-voltage electricity makes amply clear.

With the suitably scary title “115 Volts: A Deadly Shipmate,” the 1960 film details the many and various ways sailors could meet an untimely end, most of which seemed to circle back to attempts to make shipboard life a little more tolerable. The film centers not on the risks of a ship’s high-voltage installations, but rather the more familiar AC sockets used for appliances and lighting around most ships. The “familiarity breeds contempt” argument rings a touch hollow; given that most of these sailors appear to be in their 20s and 30s and rural electrification in the US was still only partially complete through the 1970s, chances are good that at least some of these sailors came from farms that still used kerosene lamps. But the point stands that plugging an unauthorized appliance into an outlet on a metal ship in a saltwater environment is a recipe for being the subject of a telegram back home.

The film shows just how dangerous mains voltage can be through a series of vignettes, many of which seem contrived but which were probably all too real to sailors in 1960. Many of the scenarios are service-specific, but a few bear keeping in mind around the house. Of particular note is drilling through a bulkhead and into a conduit; we’ve come perilously close to meeting the same end as the hapless Electrician’s Mate in the film doing much the same thing at home. As for up-cycling a discarded electric fan, all we can say is even brand new, that thing looks remarkably deadly.

The fact that they kept killing the same fellow over and over for each of these demonstrations doesn’t detract much from the central message: follow orders and you’ll probably stay alive. In an environment like that, it’s probably not bad advice.

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Curing CRT Cataracts Freshens Up Retro Roundy TVs

September 29, 2024 by 12 Comments

It’s been a long time since the family TV has had a CRT in it, and even longer since that it was using what was basically an overgrown oscilloscope tube. But “roundies” were once a thing, and even back in the early 80s you’d still find them in living rooms on TV repair calls, usually sporting a characteristic and unsightly bullseye discoloration.

Fast-forward a few decades, and roundy TVs have become collectible enough that curing their CRT cataracts is necessary for restorationists like [shango066], a skill he demonstrates in the video below. The defect comes from the composite construction of CRTs — a safety feature added by television manufacturers wisely concerned with the safety aspects of putting a particle accelerator with the twin hazards of high vacuum and high voltage in the family home. The phosphor-covered face of the tube was covered by a secondary glass cover, often tinted and frosted to improve the admittedly marginal viewing experience. This cover was often glued in place with an epoxy resin that eventually oxidized from the edges in, making the bullseye pattern.

The remedy for this problem? According to [shango066], it’s heat, and plenty of it. After liberating the tube from the remarkably clean TV chassis, he took advantage of a warm summer’s day and got the tube face cooking under a black plastic wrap. Once things were warmed up, more heat was added to really soften the glue; you can easily see the softening progress across the face of the tube in the video below. Once softened, gentle prying with wooden chopsticks completes the job of freeing the safety lens, also in remarkably good shape.

With the adhesive peeled off in an oddly satisfying manner, all that’s left is a thorough cleaning and gluing the lens back on with a little silicone sealant around the edges. We’d love to see the restored TV in operation, but that’s left to a promised future video. In the meantime, please enjoy a look at the retro necessities TV owners depended on in the good old days, which really weren’t all that good when you get down to it.

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Hackaday Links: June 30, 2024

June 30, 2024 by 14 Comments

A couple of weeks back we featured a story (third item) about a chunk of space jetsam that tried to peacefully return to Earth, only to find a Florida family’s roof rudely in the way. The 700-gram cylinder of Inconel was all that was left of a 2,360-kg battery pack that was tossed overboard from the ISS back in 2021, the rest presumably turning into air pollution just as NASA had planned. But the surviving bit was a “Golden BB” that managed to slam through the roof and do a fair amount of damage. At the time it happened, the Otero family was just looking for NASA to cover the cost of repairs, but now they’re looking for a little more consideration. A lawsuit filed by their attorney seeks $80,000 to cover the cost of repairs as well as compensation for the “stress and impact” of the event. This also seems to be about setting a precedent, since the Space Liability Convention, an agreement to which the USA is party, would require the space agency to cover damages if the debris had done damage in another country. The Oteros think the SLC should apply to US properties as well, and while we can see their point, we’d advise them not to hold their breath. We suppose something like this had to happen eventually, and somehow we’re not surprised to see “Florida Man” in the headlines.

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Danger Is My Middle Name

June 29, 2024 by 75 Comments

Last week, [Al Williams] wrote up a his experience with a book that provided almost too much detailed information on how to build a DIY x-ray machine for his (then) young soul to bear. He almost had to build it! Where the “almost” is probably both a bummer because he didn’t have an x-ray machine as a kid, but also a great good because it was a super dangerous build, of a typical sort for the 1950s in which it was published.

Part of me really loves the matter-of-factness with which “A Boy’s First Book of Linear Accelerators” tells you how you (yes you!) can build a 500 kV van der Graff generator. But at the same time, modern me does find the lack of safety precautions in many of these mid-century books to be a little bit spooky. Contrast this with modern books where sometimes I get the feeling that the publisher’s legal team won’t let us read about folding paper airplanes for fear of getting cut.

A number of us have built dangerous projects in our lives, and many of us have gotten away with it. Part of the reason that many of us are still here is that we understood the dangers, but I would be lying if I said that I always fully understood them. But thinking about the dangers is still our first and best line of defense. Humility about how well you understand all of the dangers of a certain project is also very healthy – if you go into it keeping an eye out for the unknown unknowns, you’re in better shape.

Safety isn’t avoiding danger, but rather minimizing it. When we publish dangerous hacks, we really try to at least highlight the most important hazards so that you know what to look out for. And over the years, I’ve learned a ton of interesting safety tricks from the comments and fellow hackers alike. My ideal, then, is the spirit of the 1950s x-ray book, which encourages you to get the hack built, but modernized so that it tells you where the dangers lie and how to handle them. If you’re shooting electrons, shouldn’t the book also tell you how to stay out of the way?

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Car Driving Simulators For Students, Or: When Simulators Make Sense

February 21, 2024 by 69 Comments

There are many benefits to learning to fly an airplane, drive a racing car, or operate some complex piece of machinery. Ideally, you’d do so in a perfectly safe environment, even when the instructor decides to flip on a number of disaster options and you find your method of transportation careening towards the ground, or the refinery column you’re monitoring indicating that it’s mere seconds away from going critical and wiping out itself and half the refinery with it.

Still, we send inexperienced drivers in cars onto the roads each day as they either work towards getting their driving license, or have passed their driving exam and are working towards gaining experience. It is this inexperience with dangerous situations and tendency to underestimate them which is among the primary factors why new teenage drivers are much more likely to end up in crashes, with the 16-19 age group having a fatal crash nearly three times as high as drivers aged 20 and up.

After an initial surge in car driving simulators being used for students during the 1950s and 1960s, it now appears that we might see them return in a modern format.

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How Airplanes Mostly Stopped Flying Into Terrain And Other Safety Improvements

February 8, 2024 by 13 Comments

We have all heard the statistics on how safe air travel is, with more people dying and getting injured on their way to and from the airport than while traveling by airplane. Things weren’t always this way, of course. Throughout the early days of commercial air travel and well into the 1980s there were many crashes that served as harsh lessons on basic air safety. The most tragic ones are probably those with a human cause, whether it was due to improper maintenance or pilot error, as we generally assume that we have a human element in the chain of events explicitly to prevent tragedies like these.

Among the worst pilot errors we find the phenomenon of controlled flight into terrain (CFIT), which usually sees the pilot losing track of his bearings due to a variety of reasons before a usually high-speed and fatal crash. When it comes to keeping airplanes off the ground until they’re at their destination, here ground proximity warning systems (GPWS) and successors have added a layer of safety, along with stall warnings and other automatic warning signals provided by the avionics.

With the recent passing of C. Donald Bateman – who has been credited with designing the GPWS – it seems like a good time to appreciate the technology that makes flying into the relatively safe experience that it is today.

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