Pi Picos Give Casio FX9000P Its Memory Back

March 8, 2023 by 12 Comments

Is the Casio FX9000P a calculator or a computer? It’s hard to tell since Casio did make calculators that would run BASIC. [Menadue] didn’t know either, but since it had a CRT, a Z80, and memory modules, we think computer is a better moniker.

He found one of these, but as you might expect, it needed a bit of work. There were two bad video RAM chips on the device, and [Menadue] used two Raspberry Pi Picos running a program to make them think they are RAM chips. The number of wires connecting the microcontollers might raise some eyebrows, but it does appear to get the job done.

He also used more Picos to emulate memory on cartridges. Then he used a test clip and a — you guessed it — another Pico to monitor the Z80 bus signals. It is amazing that the Pico can replace what would have been state-of-the-art memory chips and a very expensive logic analyzer.

The second video mostly shows the computer in operation. The use of Picos to stand in for so much is clever. It reminded us of the minimal Z80 computer that used an Arduino for support chips. The computer itself, though, reminded us more of a cheap version of the HP9845.

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Supercon 2022: Alec Vercruysse Can See Through Murky Water

March 8, 2023 by 4 Comments

Detecting objects underwater isn’t an easy challenge, especially when things get murky and dark. Radio waves don’t propagate well, so most techniques rely on sound. Sonar is itself farily simple, simply send out a ping and listen for an echo, and that will tell you how far something is. Imaging underwater is significantly harder, because you would additionally need to know where each echo is coming from.

To answer the question of whether it is possible to put together an ultrasonic 3D imager that would cheaply enable anyone to image objects underwater, [Alec Vercruysse] and fellow team members at the Harvey Mudd College set out to create a system that does exactly that. You can read the presentation slides (PDF) or check out the entire project in the GitHub repository.

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How To Make A Larger Air-Cored Inductor

March 8, 2023 by 20 Comments

Radio amateurs often have a love-hate relationship with home-made inductors, sharing all kinds of tips and tricks as to how the most stable nanohenry inductor can be wound. But there’s another group in the world of electronics with an interest in high-quality inductors, namely the audio enthusiasts. They need good quality inductors with a values in the millihenries, to use in loudspeaker crossover networks. [Homemade Audio] takes us through their manufacturing process for these coils, and the result is a watchable video resulting in some very well-made components.

The adjustable former is a machined aluminium affair of which we’re treated to the full manufacture. It’s likely the same results could be achieved with a 3D printed reel. The free-as-in-beer Coil64 on Windows is used to calculate the dimensions and number of turns, and it’s set up on a jig with a cordless screwdriver doing the winding. The best technique for flat layers of turns is explained, and a coat of varnish is put on each completed layer. We’re guessing this is to stop the coil “singing” at audio frequencies.

With a set of cable ties holding it together the result is a very tidy component. It’s adjusted a few turns to get the right value with an LCR meter, however experience tells us that a tiny percentage either way won’t harm the resulting network too much. If you make your own speakers, the video below the break could be extremely useful.

Need a loudspeaker primer? We have just the article for you.

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Will A.I. Steal All The Code And Take All The Jobs?

March 8, 2023 by 59 Comments

New technology often brings with it a bit of controversy. When considering stem cell therapies, self-driving cars, genetically modified organisms, or nuclear power plants, fears and concerns come to mind as much as, if not more than, excitement and hope for a brighter tomorrow. New technologies force us to evolve perspectives and establish new policies in hopes that we can maximize the benefits and minimize the risks. Artificial Intelligence (AI) is certainly no exception. The stakes, including our very position as Earth’s apex intellect, seem exceedingly weighty. Mathematician Irving Good’s oft-quoted wisdom that the “first ultraintelligent machine is the last invention that man need make” describes a sword that cuts both ways. It is not entirely unreasonable to fear that the last invention we need to make might just be the last invention that we get to make.

Artificial Intelligence and Learning

Artificial intelligence is currently the hottest topic in technology. AI systems are being tasked to write prose, make art, chat, and generate code. Setting aside the horrifying notion of an AI programming or reprogramming itself, what does it mean for an AI to generate code? It should be obvious that an AI is not just a normal program whose code was written to spit out any and all other programs. Such a program would need to have all programs inside itself. Instead, an AI learns from being trained. How it is trained is raising some interesting questions.

Humans learn by reading, studying, and practicing. We learn by training our minds with collected input from the world around us. Similarly, AI and machine learning (ML) models learn through training. They must be provided with examples from which to learn. The examples that we provide to an AI are referred to as the data corpus of the training process. The robot Johnny 5 from “Short Circuit”, like any curious-minded student, needs input, more input, and more input.

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Stranded Motorist Effects Own Rescue Using A Drone And A Cell Phone

March 8, 2023 by 79 Comments

If you’re looking for a good excuse to finally buy a drone, you probably can’t do better than claiming it can save your life.

Granted, you may never find yourself in the position of being stuck in a raging snowstorm in the middle of the Oregon wilderness, but if you do, this is a good one to keep in mind. According to news stories and the Lane County Sheriff Search and Rescue Facebook page, an unnamed motorist who was trying to negotiate an unmaintained road through the remote Willamette National Forest got stuck in the snow. This put him in a bad situation, because not only was he out of cell range, but nobody knew where he was or even that he was traveling, so he wouldn’t be missed for days.

Thankfully, the unlucky motorist played all his cards right. Rather than wandering off on foot in search of help, he stayed with his vehicle, which provided shelter from the elements. Conveniently, he also happened to have a drone along with him, which provided him with an opportunity to get some help. After typing a detailed text message to a friend describing his situation and exact location, he attached the phone to his drone and sent it straight up a couple of hundred feet — enough to get a line-of-sight connection to a cell tower. Note that the image above is a reenactment by the Search and Rescue team; it’s not clear how the resourceful motorist rigged up the drone, but we’re going to guess duct tape was involved.

When he brought the drone back down a few minutes later, he found that the queued text had been sent, and the cavalry was on the way. The Search and Rescue unit was able to locate him, and as a bonus, also found someone else nearby who had been stranded for days. So it was a win all around thanks to some clever thinking and a little technology.

A display based on magnetic viewing film

Moving Magnet Draws Stylish Shapes On Flexible Film

March 8, 2023 by 2 Comments

[Moritz v. Sivers] has a knack for making his own displays, which are typically based on some obscure physical effect. Magnetic viewing films, those thin plastic sheets that change color in response to a magnetic field, are his latest area of interest, as you can see in his Magnetic Kinetic Art Display.

The overall idea of the display is similar to a kinetic sand art table, in which a ball traces out shapes in a pile of sand. In [Moritz]’s project, the magnetic viewing film is the sand, and a 2 mm diameter magnet is the ball. The magnet is moved along the film by two sets of coils embedded inside a flex PCB mounted just below the film. One set of coils, on the top layer of the PCB, moves the magnet in the x direction, while a second set on the bottom layer moves it in the y direction.

A flex PCB with coils on both sides
The flex PCB is small, but carries lots of windings

[Moritz] used a flex PCB not because it had to be bendy, but to keep the two sets of coils as close together in the z direction as possible. This helps to avoid a big difference in strength between the two directions. To drive the coils, he used a pair of TB6612FNG stepper motor drivers, controlled by a Wemos D1 Mini.

The housing was 3D printed mostly from PLA, but with a few bits done in PETG. This was for structural rigidity as well as thermal performance — the coils can carry up to two amps and get pretty warm as a result.

The video, embedded below, shows some of the shapes that can be drawn: squares, spirals and even digits to turn the display into a clock. [Moritz] got the PCB coil idea from a project by [bobricius], and cleverly extended it into a useful product. It’s not the first time [Moritz] used magnetic viewing film to make a clock, either.

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Pulling Data From HDMI RF Leakage

March 7, 2023 by 25 Comments

A long-running story in the world of electronic security has been the reconstruction of on-screen data using RF interference from monitors or televisions. From British TV detector vans half a century ago to 1980s scare stories about espionage, it was certainly easy enough to detect an analogue CRT with nothing more than an AM broadcast radio receiver. But can this still be done in the digital age? It’s something [Windytan] has looked into, as she reconstructs images using leakage from HDMI cables.

The tale starts with a mystery RF noise, soon identified as not unlike the scanning frequencies of a video signal. Plotting the noise intensities while treating the supposed scanning frequencies as video synchronization yields a shadowy version of her Raspberry Pi desktop, so she’s on to something. It’s important to note that this isn’t a video signal she’s receiving, but the noise associated with the bit transitions in an uncompressed digital video stream, so she quickly concludes that trying to resolve color would be futile.

It does however leave the tantalizing possibility of using this as a medium to wirelessly export data from a compromised machine, and it’s down this route she goes. She finally arrives on a scheme of encoding data as lines of individual colors that look like interference patterns over a desktop, and from there can send and retrieve files. It works for digital audio streams, and as shown in the video below, even an MJPEG video stream, hidden in the noise from a video signal. That’s impressive work, by any standard!

We covered those BBC detector vans in detail a while back.

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