ColecoVision Cart Rises From Ashes

We felt bad for [Mark] of Mark Fixes Stuff. Apparently, his house burned down and took virtually everything, including his retrocomputer collection. He did manage to pull out a few things from the remains including a ColecoVision cartridge that was — honestly — melted. We probably would have written it off, but [Mark] was determined to recover something.

He was fortunate that the PCB was not burned, but it was covered in soot and possibly other things. However, the case looked like a chocolate bar left on a dashboard for a few summer days in the tropics.

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The line injector shown characterising the PSRR of an AMS1117 regulator, with a bunch of stuff connected to it through SMA jacks

A Simple Line Injector Shows You The Wonderful World Of PSRR

[limpkin] writes us to show a line injector they’ve designed. The principle is simple — if you want to measure how much PSU noise any of your electronic devices let through, known as PSRR (Power Supply Rejection Ratio), you can induce PSU noise with this board, and then measure noise on your device’s output. The board is likewise simple. A few connectors, resistors, and caps, and a single N-FET!

You do need a VNA, but once you have that, you get a chance to peek into an entire world of insights. Does that 1117 LDO actually filter out noise better than a buck regulator? Is it enough to use a Pi filter for that STM32’s ADC rail, and do the actual parts you’re using actually help with that task? How much noise does your device actually let through in the real world, after being assembled with the specific components you’ve picked? [limpkin] shows us a whole bunch of examples – putting regulators, filters and amplifiers to the test, and showing us how there’s more than meets the eye.

Everything is open source, with full files available on the blog. And, if you want it pre-assembled, tested and equipped with the CNC-milled case, you can get it on Tindie or Lektronz! Of course, even without a tool like this, you can still get good filter designs done with help of computer-aided modelling.

We thank [alfonso] for sharing this with us!

3D Printer Hot Off The Griddle

If you look at [Proper Printing’s] latest video — see below — you’ll immediately get the idea behind his latest printer. There are two heads on two separate gantries, which, of course, opens up many possibilities. But when you think you’ve seen enough, you find out the heated bed is a kitchen griddle, and… well, for us, we had to keep watching.

The heated bed idea was interesting, although the flatness left something to be desired. While it is a simple idea, getting the two gantries to move reliably across the hotbed griddle took a lot of parts and a careful design. We wonder how evenly the griddle heats — ours definitely has hot spots when we cook with it.

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ESP32 Provides Distraction-Free Writing Experience

Writing out a few thousand words is easy. Getting them in the proper order, now that’s another story entirely. Sometimes you’ll find yourself staring at a blank page, struggling to sieve coherent thoughts from the screaming maelstrom swirling around in your head, for far longer than you’d care to admit. Or so we’ve heard, anyway.

Unfortunately, there’s no cure for writer’s block. But many people find that limiting outside distractions helps to keep the mental gears turning, which is why [Un Kyu Lee] has been working on a series of specialized writing devices. The latest version of the Micro Journal, powered by the ESP32, goes a long way towards achieving his goals of an instant-on electronic notebook.

The writing experience on the Micro Journal is unencumbered by the normal distractions you’d have on a computer or mobile device, as the device literally can’t do anything but take user input and save it as a text file. We suppose you could achieve similar results with a pen and a piece of paper…but where’s the fun in that? These devices are more widely known as writerdecks, which is an extension of the popular cyberdeck concept of hyper-personalized computers.

This newest Micro Journal, which is the fourth iteration of the concept for anyone keeping score, packs a handwired 30% ortholinear keyboard, a 2.8″ ILI9341 240×320 LCD (with SD card slot), ESP32 dev board, and an 18650 battery with associated charging board into a minimalist 3D printed enclosure.

Unable to find any suitable firmware to run on the device, [Un Kyu Lee] has developed his own open source text editor to run on the WiFi-enabled microcontroller. While the distraction-free nature of the Micro Journal naturally means the text editor itself is pretty spartan in terms of features, it does  allow syncing files with Google Drive — making it exceptionally easy to access your distilled brilliance from the comfort of your primary computing device.

While the earlier versions of the Micro Journal were impressive in their own way, we really love the stripped down nature of this ESP32 version. It reminds us a bit of the keezyboost40 and the EdgeProMX, both of which were entered into the 2022 Cyberdeck Contest.

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A Drone Motor Does E-Bikes

On paper, the motors from both an electric bicycle and a drone can both take about 500 watts or so of power. Of course, their different applications make them anything but equivalent, as the bike motor is designed for high torque at low speed while the drone motor has very little torque but plenty of speed. Can the drone motor do the bike motor’s job? [Pro Know] makes it happen, with a set of speed reducing and torque increasing belts.

The build takes a pretty ordinary bicycle, and replaces the rear brake disk with a large pulley for a toothed belt, which drives a smaller pulley, and through a shaft another set of pulleys to the drone motor. The bracket to hold all this and the very large pulley on the wheel are all 3D printed in PLA-carbon fiber mix.

When it’s assembled, it runs the bike from a small lithium ion pack. That’s not unexpected, but if we’re honest we’d have our doubts as to whether this would survive the open road. It’s evidently a novelty for a YouTube video, and we’d be interested to see how hot the little motor became. However what’s perhaps more interesting is the choice of filament.

Could carbon fibre PLA be strong enough to print a toothed belt pulley? We’d be interested to know more. We saw the same filament combo being tested recently, after all.

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Fictional Computers: The Three Body Problem

If you intend to see the Netflix series “The Three Body Problem” or you want to read the Hugo-winning story from Chinese author [Cixin Liu], then you should probably bookmark this post and stop reading immediately. There will be some mild spoilers. You have been warned.

While the show does have some moments that will make your science brain cringe, there is one scene that shows a computer that could actually be built. Would it be practical? Probably not in real life, but in the context provided by the show, it was perfectly feasible. It could have, however, been done a little better, but the idea was — like many great ideas — both deceptively simple and amazingly profound. The computer was made of human beings. I’m not talking like Dune’s mentats — humans with super brains augmented by drugs or technology. This is something very different.


This is your last chance. There are spoilers ahead, although I’ll try to leave out as much as I can. In the story, top scientists receive a mysterious headset that allows them to experience totally immersive holodeck-style virtual reality. When they put the headset on, they are in what appears to be a game. The game puts you in a historical location — the court of Henry VIII or Ghengis Kahn. However, this Earth has three suns. The planet is sometimes in a nicely habitable zone and sometimes is not. The periods when the planet is uninhabitable might have everything bursting into flames or freezing, or there might not be sufficient gravity to hold them on the planet’s surface. (Although I’ll admit, I found that one hard to grasp.)

Apparently, the inhabitants of this quasi-Earth can hibernate through the “chaotic eras” and wait for the next “stable era” that lasts a long time. The problem, as you probably know, is that there is no general closed-form solution for the three-body problem. Of course, there are approximations and special cases, but it isn’t easy to make long-term predictions about the state of three bodies, even with modern computers.

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Hackaday Podcast Episode 265: Behind The Epic SSH Hack, 1980s Cyber Butler, The Story Of Season 7

This week, Editor-in-Chief Elliot Williams and Kristina Panos convened once again to give the lowdown on this week’s best hacks. First up in the news — it’s giga-sunset time for Gigaset IoT devices, which simultaneously became paperweights on March 29th. And all that Flipper Zero panic? It has spread to Australia, but still remains exactly that: panic.

Then it’s on to What’s That Sound. Kristina failed again, although she was in the right neighborhood. Can you get it? Can you figure it out? Can you guess what’s making that sound? If you can, and your number comes up, you get a special Hackaday Podcast t-shirt.

Then it’s on to the hacks, beginning with the terrifying news of an xz backdoor. From there, we marvel at a 1980s ‘butler in a box’ — a voice-activated home automation system — and at the idea of LoRa transmissions without a radio. Finally, we discuss why you don’t want to piss off Trekkies, and whether AI has any place in tech support.

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 and savor at your leisure.

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