A Modem As A Cassette Interface

January 24, 2025 by Jenny List 20 Comments

At least some in the audience will at some time in the distant past have loaded or saved a program on cassette, with an 8-bit home computer. The machine would encode binary as a series of tones which could be recorded to the tape and then later retrieved. If you consider the last sentence you’ll quickly realize that it’s not too far away from what a modem does, so can a modem record to cassette and decode it back afterwards? [Jesse T] set out to give it a try, and as it turns out, yes you can.

The modem talks and listens to the cassette recorder via circuitry that provides some signal conditioning and amplification, as well as making a dial tone such that the modem thinks it’s talking to a real phone line. An Arduino steps in as dial tone creator.

Of course, this is hardly a viable solution to 21st century data storage need, but that’s hardly the point as it’s a cool hack. We like it, and oddly we’ve seen a similar technique used with a retrocomputer in the past.

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Bouncing Signals Off Of Satellites Other Than The Moon

January 24, 2025 by Bryan Cockfield 7 Comments

The moon is a popular target for ham radio operators to bounce signals since it’s fairly large and follows a predictable path. There are some downsides, though; it’s not always visible from the same point on Earth and is a relatively long way away. Thinking they could trade some distance for size, an amateur radio group from the Netherlands was recently able to use a radio telescope pointed at a geostationary satellite to reflect a signal back down to Earth, using this man-made satellite to complete the path instead of the more common natural one.

While there are plenty of satellites in orbit meant for amateur radio communication (including the International Space Station, although it occasionally does other things too), these all have built-in radio transmitters or repeaters specifically meant for re-transmitting received signals. They’re also generally not in geostationary orbit. So, with a retired radio telescope with a 20-meter dish aimed directly at one of the ones already there, they sent out a signal which bounced off of the physical body of the satellite and then back down where it was received by a station in Switzerland. Of course, the path loss here is fairly extreme as well since the satellite is small compared to the moon and geostationary orbit is a significant distance away, so they used the Q65 mode in WSJT-X which is specifically designed for recovering weak signals.

Don’t break out the tape measure Yagi antenna to try this yourself just yet, though. This path is not quite as reliable as Earth-Moon-Earth for a few reasons the group is not quite sure about yet. Not every satellite they aimed their dish at worked, although they theorize that this might be because of different shapes and sizes of the satellites or that the solar panels were not pointing the correct direction. But they were able to make a few contacts using this method nonetheless, a remarkable achievement they can add to their list which includes receiving a signal from one of the Voyager spacecraft.

Bosch Starter Motor Freed From Mercedes Prison

January 24, 2025 by Bryan Cockfield 78 Comments

Vehicle alternators are interesting beasts. Produced on a massive scale, these electric machines are available for a minimum of cost and contain all kinds of great parts: some power electronics and a belt-driven generator are generally standard fare. This generator can also be used as a motor with only minor changes to the machine as a whole, so thanks to economies of scale it’s possible to get readily-available, powerful, compact, and cheap motors for all kinds of projects using alternators as a starting point. [LeoDJ] noticed that this starter motor in a modern Mercedes had some interesting benefits beyond all of these perks, but it took a bit more work to get up and running than a typical alternator would have.

The motor, built by Bosch, can be found in the Mercedes E200 EQ Boost. This is a hybrid car, but different than something like a Prius in that it doesn’t have an electric motor capable of powering the car on its own. Instead it uses a combination starter motor/alternator/generator to provide extra power to the engine during acceleration, increasing efficiency and performance. It can also charge the small battery bank when the car slows down. Vehicles that use this system need much beefier alternators than a standard car, but liberating it from the car means that it has much more power available than a typical alternator would.

There were a number of issues to solve, though. Being that the motor/alternator has to do all of this extra work (and that it came out of a car whose brand is known for being tedious to work on in the first place) it is much more complicated than an off-the-shelf alternator. [LeoDJ] has been able to get his to spin by communicating with it over the CAN bus, but there’s still some work to be done before it goes into something like an impressively fast electric bicycle.

Thanks to [RoganDawes] for the tip!

Small Print Bed? No Problem!

January 24, 2025 by Bryan Cockfield 6 Comments

One of the major limitations of 3D printers is the size of the printable area. The robotic arm holding the printer head can only print where it can reach, after all. Some methods of reducing this constraint have been tried before, largely focusing on either larger printers or printer heads that are mobile in some way. Another approach to increasing the size of prints beyond the confined space typical of most consumer-grade 3D printers is to create some sort of joinery into the prints themselves so that larger things can be created. [Cal Bryant] is developing this jigsaw-based method which has allowed him to produce some truly massive prints.

Rather than making the joints by hand, [Cal]’s software will cut up a model into a certain number of parts when given the volume constraints of a specific 3D printer so it can not only easily print the parts, but also automatically add the jigsaw-like dovetail joints to each of the sections of the print. There were a few things that needed prototyping to get exactly right like the tolerance between each of the “teeth” of the joint, which [Cal] settled on 0.2 mm which allows for a strong glued joint, and there are were some software artifacts to take care of as well like overhanging sections of teeth around the edges of prints. But with those edge cases taken care of he has some working automation software that can print arbitrarily large objects.

[Cal] has used this to build a few speaker enclosures, replacing older MDF designs with 3D printed ones. He’s also built a full-size arcade cabinet which he points out was an excellent way to use up leftover filament. Another clever way we’ve seen of producing prints larger than the 3D printer is to remove the print bed entirely. This robotic 3D printer can move itself to a location and then print directly on its environment.

Sony Ends Blu-Ray, MD And MiniDV Media Production

January 24, 2025 by Maya Posch 29 Comments

With the slow demise of physical media the past years, companies are gradually closing shop on producing everything from the physical media itself to their players and recorders. For Sony this seems to have now escalated to where it’ll be shuttering its recordable optical media storage operations, after more than 18 years of producing recordable Blu-ray discs. As noted by [Toms Hardware] this also includes minidisc (MD) media and MiniDV cassettes.

We previously reported on Sony ending the production of recordable Blu-ray media for consumers, which now seems to have expanded to Sony’s remaining storage media. It also raises the likelihood that Sony’s next game console (likely PlayStation 6) will not feature any optical drive at all as Blu-ray loses importance. While MiniDV likely was only interesting to those of us still lugging one of those MiniDV camcorders around, the loss of MD production may be felt quite strongly in the indie music scene, where MD is experiencing somewhat of a revival alongside cassette tapes and vinyl records.

Although it would appear that physical media is now effectively dead in favor of streaming services, it might be too soon to mark its demise.

Hackaday Podcast Episode 305: Caustic Clocks, Practice Bones, And Brick Layers

January 24, 2025 by Kristina Panos 2 Comments

This week, Hackaday’s Elliot Williams and Kristina Panos joined forces and Wonder-Twin rings to bring you the latest news, mystery sound, and of course, a big bunch of hacks from the previous week.

First up in the news: Big boo to Bambu Labs, who have tried to clarify their new authentication scheme and probably only dug themselves in deeper with their customers.

On What’s That Sound, Kristina didn’t get close at all, but at least had a guess this time. Do know what it is? Let us know, and if you’re right and your number comes up, you can keep warm in a limited edition Hackaday Podcast t-shirt.

Then it’s on to the hacks and such beginning with a rather nice reverse-engineering of the Yamaha PRS-E433 keyboard, which led to a slice of Bad Apple playing on the tiny screen.

After that, we take a look at an NES musical instrument, how to make wires explode with energy, and a really cool space mouse that uses flexures. Finally, we talk about a piece of forgotten Internet history, and a whole bunch of keyboards.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download in DRM-free MP3 and savor at your leisure.

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This Week In Security: ClamAV, The AMD Leak, And The Unencrypted Power Grid

January 24, 2025 by Jonathan Bennett 10 Comments

Cisco’s ClamAV has a heap-based buffer overflow in its OLE2 file scanning. That’s a big deal, because ClamAV is used to scan file attachments on incoming emails. All it takes to trigger the vulnerability is to send a malicious file through an email system that uses ClamAV.

The exact vulnerability is a string termination check that can fail to trigger, leading to a buffer over-read. That’s a lot better than a buffer overflow while writing to memory. That detail is why this vulnerability is strictly a Denial of Service problem. The memory read results in process termination, presumably a segfault for reading protected memory. There are Proof of Concepts (PoCs) available, but so far no reports of the vulnerability being used in the wild.
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