Amateur Rocket Aims For The Kármán Line, One Launch At A Time

October 10, 2022 by Ryan Flowers 17 Comments

When it comes to high-powered rocketry, [BPS.space] has the unique distinction of being the first to propulsively land a solid-fueled model rocket. How could he top that? Well, we’re talking about actual rocket science here, and the only way is up! All the way up to the Kármán line: 100 km. How’s he going to get there? That’s the subject of the video below the break.

Getting to space is notoriously difficult because it’s impossible to fully test for the environment in which a rocket will be flying. But there is quite a lot that can be tested, and those tests are the purpose of a rocket that [Joe] at [BPS.space] calls Avalanche. Starting with a known, simple design as a test bed, numerous launches are planned in order to iterate quickly through several launches- three of which are covered just in this video.

The goal with Avalanche isn’t to get to the Kármán line, but to learn the lessons needed to build a far bigger rocket that will. A home-brewed guidance system, a gimballed spin-stabilized 4K camera, and the descent system are among those being tested and perfected.

Of course, you don’t have to be a rocket scientist to have fun with prototyping. Sometimes you just want to 3D print a detonation engine, no matter how long it won’t last. Why not?

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A CRT Monitor From An Obsolete Logic Analyzer

October 7, 2022 by Jenny List 15 Comments

The designers of older equipment that contained a CRT monitor rarely made the effort to design their own driver and deflection circuitry. Instead they were more likely to buy an off the shelf assembly from a monitor manufacturer, and simply supply it with their video. [TomV] has an old HP 16500A logic analyzer, and in it he found a Sony monitor chassis. With a quest for a microfiche service manual and a bit of reverse engineering, he was able to hook it up to a VGA port and use it as an extension monitor for his laptop.

The monitor chassis is a Sony CHM-9001-00, which sports their 10″ Trinitron tube. These were among the very best CRT tubes of the day, making it the type of module 1990s hacker would have been very pleased to get their hands on. Here in 2022 a look at the monitor’s 40-pin connector reveals a standard RGB interface which the service manual confirms is within the voltage range to be driven from a VGA output. A Thinkpad X220 is pressed into service, with a 576 by 360 pixel at 60 Hz video mode defined, and there we have it, a modern desktop on an obsolete piece of test equipment.

The intended destination for this monitor is a small arcade cabinet, so it needed to be independent of the HP chassis. The required 120 VDC supply comes from an inverter designed for solar battery charging, which balked at the inrush current from the monitor when fed with 12 V. Increasing the supply voltage on the low voltage side solved that, leading to a very serviceable monitor. We have no use for one, but we’d be lying if we said we didn’t want one.

Perhaps you may have wondered, what made Trinitrons so good?

An 8-bit ISA card being plugged into a motherboard

Reverse-Engineering An ISA Card To Revive An Ancient CD-ROM Drive

October 4, 2022 by Robin Kearey 22 Comments

Being an early adopter is great if you enjoy showing off new gadgets to your friends. But any new technology also brings the risk of ending up at the wrong side of a format war: just ask anyone who committed to HD-DVD fifteen years ago. If, on the other hand, you were among the few who invested in CD-ROM when it was first released in the mid-1980s, you definitely made the right choice when it came to storage media. However, it was a bit of a different story for the interface that hooks up the CD drive to your computer, as [Tech Tangents] found out when he managed to get his hands on a first-generation CM100 drive. (Video, embedded below.)

That wonderful piece of 1985 technology is not much smaller than the IBM PC it was designed to connect to, and it originally came with its own CM153 ISA interface card. But while most eBay sellers recognized the historic value of a pioneering CD-ROM drive, the accompanying PC was typically a dime-a-dozen model and was thrown out with the rare interface card still inside. Even after searching high and low for over a year, the only information [Tech Tangents] could find about the card was a nine year old YouTube video that showed what the thing looked like.

Luckily, the maker of that video was willing to take high-resolution pictures of the card, which allowed [Tech Tangents] to figure out how it worked. As it turned out, the card was entirely made from standard 7400 series logic chips as well as an 8251 USART, which meant that it should be possible to design a replacement simply by following all the traces on the board. [Tech Tangents] set to work, and after a few weeks of reverse-engineering he had a complete schematic and layout ready in KiCAD.

After the PCBs were manufactured and populated with components, it was time to test the new card with the old drive. This wasn’t a simple process either: as anyone who’s tried to get obscure hardware to work in MS-DOS will tell you, it involves countless hours of trying different driver versions and setting poorly documented switches in CONFIG.SYS. Eventually however, the driver loaded correctly and the ancient CD-ROM drive duly transferred the files stored on a Wolfenstein 3D disk.

If you’re lucky enough to own a CM100 or a similar drive from that era, you’ll be happy to know that all design files for the CM153 clone are available on GitHub. This isn’t the first time someone has had to re-create an interface board from pictures alone: we’ve seen a similar project involving a SCSI card for a synthesizer. Thanks for the tip, [hackbyte]!

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A man removing a module from a 1960s computer

Ancient Nuclear Plant Computer Finds New Home In Bletchley Museum

October 3, 2022 by Robin Kearey 20 Comments

Although technology keeps advancing every year, safety-critical systems in factories and power plants typically stay with the technology that was available when they were built, in the spirit of “don’t fix it if it ain’t broke”. When it comes to safety, there are probably few systems more critical than nuclear power plants, and as a result one power station in Dungeness, in the south-east of England, was controlled by the same Ferranti Argus 500 computer from the early 1970s until the reactor was shut down in 2018.

The national Museum of Computing in Bletchley was lucky enough to be allowed to scavenge the old computer from the decommissioned plant, and volunteers at the museum have managed to get it running again in its new home. They describe the process in the video embedded below, and demonstrate a few features of this rather unique piece of 1970s technology.

The computer consists of several large cabinets that house enormous PCBs full of diode-transistor logic (DTL) chips, made by Ferranti itself. It comes with 32 kilo-words, or 96 kilobytes, of magnetic core memory, and was designed to run programs stored on punched tape. However, the paper tape reader was removed at some point in the computer’s life and replaced with a PC-based system that emulates the tape reader’s output through its parallel port. This was probably sometime during the 1990s, judging from the fact that the https://hackaday.com/tag/magnetic-core-memory/PC runs OS/2.

Setting up the computer in its new home was complicated by the fact that hundred of cables had to be disconnected in order to move the system out of the power plant. With the help of decades-old documentation, and the experience of one volunteer who used to be a Ferranti engineer, they eventually got it into a state where it could run programs again.

Ultimately, the Argus 500 will be turned into a live exhibit that will simulate a power station alongside another computer that was rescued from a different nuclear plant. Depending on the availability of some parts that are still missing, this might happen later this year, or perhaps next year. In any case, the museum already has a collection that’s well worth visiting if you’re in the area. The story of how they rescued a neglected IBM 360 also makes for fascinating reading. Continue reading “Ancient Nuclear Plant Computer Finds New Home In Bletchley Museum” →

DIY Wind Tunnel Aims To Educate The Youth

October 1, 2022 by Lewin Day 20 Comments

Typically, when we talk about wind tunnels, we think of the big facilities in use by the aerospace and motorsports industries. However, there’s nothing stopping you building a wind tunnel of your very own, and it may even be easier than you think! [Jude Pullen] has whipped up just such a design with DIY in mind.

Intended for high school Design & Technology (D&T) classes, it uses relatively simple materials construction techniques. The airflow straightener is built out of PVC pipes, and the end boxes built out of cardboard. The transparent walls for observation are created out of acrylic, while a simple fan provides the necessary flow. The desk-sized wind tunnel can then be instrumented with a manometer, tachometer, and anemometer to measure pressure, fan speed, and wind speed. [Jude] also explores experiments that can be run in the wind tunnel, such as working with a small balsa wood glider and measuring the lift it generates with a scale.

[Jude] has a very pragmatic and real-world understanding of such projects, too. He notes the difference between making things to measure, and making them to fit, and highlights the values of both approaches. It’s a much more holistic approach than simply berating students to “do it right” or “do it better” when making things in a D&T class.

Use of a basic wind tunnel is often not taught to engineering students until at least the second or third year of an engineering degree, after all the boring math and static analysis has been dealt with. However, there’s no reason high school physics students can’t understand the physics involved, and they’re more than capable of undertaking such a build. Starting such education early often nets huge benefits for individuals and their eventual careers.

Once you’ve got yourself a wind tunnel, you might want to start thinking about some flow visualization, which gets really exciting.

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Lamp Flashing Module Is Perfect For Automotive Use

October 1, 2022 by Lewin Day 17 Comments

Modern cars tend to have quite advanced lighting systems, all integrated under the control of the car’s computer. Back in the day, though, things like brake lights and indicators were all done with analog electronics. If your classic car needs a good old-fashioned flasher module, you might find this build from [DIY Guy Chris] useful.

It’s an all-analog build, with no need for microcontrollers or other advanced modern contrivances. Instead, a little bipolar PNP transistor and a beefier NPN MOSFET as an oscillator, charging and discharging a capacitor to create the desired flashing behavior. Changing the size of the main capacitor changes the flash rate. The MOSFET is chosen as running 12 volt bulbs requires a decent amount of current. The design as drawn is intended to run up to eight typical automotive bulbs, such as you might find in indicator lamps. However, [Chris] demonstrates the circuit with just four.

Flasher circuits were in regular use well into the 1990s. The original Mazda Miata has a very similar circuit tucked up under the dashboard to run the turn signals. These circuits can be hard to find for old cars, so building your own may be a useful workaround if you’re finding parts hard to come by. Video after the break.

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Finding Digital Solace In An Old Nokia Phone

September 20, 2022 by Tom Nardi 9 Comments

We don’t have to tell you that the current mobile phone market is a bit bleak for folks who value things like privacy, security, and open source. While there have been a few notable attempts to change things up, from phone-optimized versions of popular Linux distributions to the promise of modular handsets — we still find ourselves left with largely identical slabs released by a handful of companies which often seem to treat the customer as a product.

Instead of waiting for technological relief that may never come, [vrhelmutt] has decided to take matters into their own hands by looking to the past. Specifically, by embracing the relatively uncommon Nokia Asha 210. Released in 2013, this so-called “feature phone” offers a full QWERTY keyboard, Nokia’s Series 40 operating system, WiFi, Bluetooth, and a removable BL-4U battery. Unfortunately, with 2G cellular networks quickly being shut down, it’s not likely to get a signal for much longer (if at all, depending on where you live).

So why would you want to use some weird old Nokia phone in 2022? [vrhelmutt] argues that there’s a whole world of S40 software out there that can still be put to use, ranging from games to SSH clients. It’s also relatively easy to develop your own S40 applications in Java, with the original software development kit still freely available online. Combined with the solid (if considerably dated) hardware, this makes the Nokia Asha 210 a surprisingly compelling choice for a pocket hacking platform.

Whether you’re looking for a cheap device that will let you chat on IRC from your couch, or want to write your own custom software for controlling your home automation or robotics projects, you might want to check the second-hand market for a Nokia Asha 210. Or if you’re eager to get experimenting immediately, [vrhelmutt] is actually selling these phones pre-loaded with a wide array of games and programs. Don’t consider this to be an official endorsement; frankly we’re not feeling too confident about the legality of redistributing all this software, but at least it’s an option for those looking to get off the modern smartphone thrill-ride.

If you’re looking for something even farther removed from today’s mobile supercomputers, perhaps we could interest you in the Rotary Un-Smartphone.

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