classic hacks

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Vintage Plasma Display Shows Current Rad Levels

July 26, 2025 by 11 Comments

It’s hard to argue that Soviet-Era nuclear engineering may have some small flaws, what with the heavily-monitored exclusion zone around Chernobyl No.4. Evidently, their industrial designers were more on-the-ball, because [Alex] has crafted the absolute most stylish fallout monitor we’ve ever seen, with ESP32 and a vintage Soviet-designed plasma display to indicate radiation levels in the exclusion zone.

Since the device is not located within the zone, [Alex] is using the ESP32 to access sensor values published via an API at SaveEcoBot. He also includes a Geiger counter module for the background level at the current location. That’s straightforward enough– integrating the modern microcontroller with the vintage plasma display is where the real hacking comes in. Though they might not be as vintage as you think: apparently the Elektronika MS6205 remained in production until 2005, but 2005 is still vintage. [Alex] notes in the instructions on hackaday.io that we’re actually looking for a post-1995 model to follow along.

The Elektronika MS6205 is based on a 100×100 pixel plasma matrix, but it is operated as a text-only display with Latin and Cyrillic characters in ROM. The ROM also includes some extra symbols and Greek letters (the gamma will come in handy for this application) that can be unlocked by cutting a trace on the board and replacing it with a bodge wire. Igniting the display requires 250V, which will require more work for North Americans than it does in Ukraine. Driving the display requires interfacing with the 7-bit data bus and 8-bit address bus, but [Alex] has made the wiring and code available on the project site if you’re interested in these devices. If you want to watch it in action and get more background, check out the video embedded below.

These sorts of monochrome plasma displays have a lot of charm, and are absolutely worth reverse-engineering if you get your hands on different model. If you like the vibe of this display, you might also be interested in Vacuum Fluorescent Displays, which can be easier to find in the West.

Thanks to [Alex] for the tip. Like the tireless IEA workers at Chernobyl, we’re always monitoring the radiation level of our tips line.  Continue reading “Vintage Plasma Display Shows Current Rad Levels” →

Zine Printing Tips From A Solopreneur

July 25, 2025 by 28 Comments

Zines (self-produced, small-circulation publications) are extremely DIY, and therefore punk- and hacker-adjacent by nature. While they can be made with nothing more than a home printer or photocopier, some might benefit from professional production while losing none of their core appeal. However, the professional print world has a few gotchas, and in true hacker spirit [Mabel Wynne] shares things she learned the hard way when printing her solo art zine.

As with assembling hardware kits, assembling a zine can take up a lot of physical table space.

[Mabel] says the most useful detail to nail down before even speaking to printers is the zine’s binding, because binding type can impact layout and design of an entire document. Her advice? Nail it down early, whether it’s a simple saddlestitch (staples through a v-shaped fold of sheets), spiral binding (which allows a document to lay flat), or something else.

Aside from paper and print method (which may be more or less important depending on the zine’s content) the other thing that’s important to consider is the finishing. Finishing consists of things like cutting, folding, and binding of the raw printed sheets. A printer will help arrange these, but it’s possible to do some or even all of these steps for oneself, which is not only more hands-on but reduces costs.

Do test runs, and prototype the end result in order to force unknown problems to the surface before they become design issues. Really, the fundamentals have a lot in common with designing and building kits or hardware. Check out [Mabel]’s article for the full details; she even talks a little about managing money and getting a zine onto shelves.

Zine making is the DIYer’s way to give ideas physical form and put them into peoples’ hands more or less directly, and there’s something wonderfully and inherently subversive about that concept. 2600 has its roots in print, but oddball disk magazines prove one doesn’t need paper to make a zine.

Die Cut Machine Makes Portable Metal Cuts

July 12, 2025 by 11 Comments

[Kevin Cheung] likes to upcycle old soda cans into — well — things. The metal is thin enough to cut by hand, but he’d started using a manual die-cutting machine, and it worked well. The problem? The machine was big and heavy, weighing well over 30 pounds. The solution was to get a lightweight die cutter. It worked better than expected, but [Kevin] really wanted it to be more portable, so he stripped it down and built the mechanism into a new case.

The video below isn’t quite a “how-to” video, but if you like watching someone handcraft something with a lot of skill, you’ll enjoy it. It also might give you ideas about how you could use one of these cutters, even if you don’t bother building a nice case for it.

We’ve seen cutters that use computer control, but they aren’t inexpensive. They will, however, make the same kind of cuts. But these manual die cutters are very inexpensive, and you simply have to find a way to make the die. You can easily make them for cutting paper, and, with the right materials, you can make the kind you see in [Kevin]’s video, too.

We have to admit, carrying the gizmo into a public place seemed to make a lot of people happy. So maybe portability is a good goal. But either way, you can have some fun with a machine like that.

If you want to cut paper, these work great. If you want paper to make the cuts, we have just the thing for you.

Continue reading “Die Cut Machine Makes Portable Metal Cuts” →

The 555 Writ Large

July 12, 2025 by 25 Comments

Few electronic ICs can claim to be as famous as the 555 timer. Maybe part of the reason is that the IC doesn’t have a specific function. It has a lot of building blocks that you can use to create timers and many other kinds of circuits. Now [Stoppi] has decided to make a 555 out of discrete components. The resulting IC, as you can see in the video below, won’t win any prizes for diminutive size. But it is fun to see all the circuitry laid bare at the macro level.

The reality is that the chip doesn’t have much inside. There’s a transistor to discharge the external capacitor, a current source, two comparators, and an RS flip flop. All the hundreds of circuits you can build with those rely on how they are wired together along with a few external components.

Even on [stoppi]’s page, you can find how to wire the device to be monostable, stable, or generate tones. You can also find circuits to do several time delays. A versatile chip now blown up as big as you are likely to ever need it.

Practical? Probably not, unless you need a 555 with some kind of custom modification. But for understanding the 555, there’s not much like it.

We’ve seen macro 555s before. It is amazing how many things you can do with a 555. Seriously.

Continue reading “The 555 Writ Large” →

Kids Vs Computers: Chisanbop Remembered

July 9, 2025 by 14 Comments

If you are a certain age, you probably remember the ads and publicity around Chisanbop — the supposed ancient art of Korean finger math. Was it Korean? Sort of. Was it faster than a calculator? Sort of. [Chris Staecker] offers a great look at Chisanbop, not just how to do it, but also how it became such a significant cultural phenomenon. Take a look at the video below. Long, but worth it.

Technically, the idea is fairly simple. Your right-hand thumb is worth 5, and each finger is worth 1. So to identify 8, you hold down your thumb and the first three digits. The left hand has the same arrangement, but everything is worth ten times the right hand, so the thumb is 50, and each digit is worth 10.

With a little work, it is easy to count and add using this method. Subtraction is just the reverse. As you might expect, multiplication is just repeated addition. But the real story here isn’t how to do Chisanbop. It is more the story of how a Korean immigrant’s system went viral decades before the advent of social media.

You can argue that this is a shortcut that hurts math understanding. Or, you could argue the reverse. However, the truth is that this was around the time the calculator became widely available. Math education would shift from focusing on getting the right answer to understanding the underlying concepts. In a world where adding ten 6-digit numbers is easy with a $5 device, being able to do it with your fingers isn’t necessarily a valuable skill.

If you enjoy unconventional math methods, you may appreciate peasant multiplication.

Continue reading “Kids Vs Computers: Chisanbop Remembered” →

Oscillator Negativity Is A Good Thing

July 8, 2025 by 6 Comments

Many people who get analog electronics still struggle a bit to design oscillators. Even common simulators often need a trick to simulate some oscillating circuits. The Barkhausen criteria state that for stable oscillation, the loop gain must be one, and the phase shift around the feedback loop must be a multiple of 360 degrees. [All Electronics Channel] provides a thorough exploration of oscillators and, specifically, negative resistance, which is punctuated by practical measurements using a VNA. Check it out in the video below.

The video does have a little math and even mentions differential equations, but don’t worry. He points out that the universe solves the equation for you.

In an LC circuit, you can consider the losses in the circuit as a resistor. That makes sense. No component is perfect. But if you could provide a negative resistance, it would cancel out the parasitic resistance. With no loss, the inductor and capacitor will go back and forth, electrically, much like a pendulum.

So, how do you get a negative resistance? You’ll need an active device. He presents some example oscillator architectures and explains how they generate negative resistances.

Crystals are a great thing to look at with a VNA. That used to be a high-dollar piece of test gear, but not anymore.

Continue reading “Oscillator Negativity Is A Good Thing” →

Reliving VHS Memories With NFC And ESPHome

July 3, 2025 by 10 Comments

Like many of us of a certain vintage, [Dillan Stock] at The Stock Pot is nostalgic for VHS tapes. It’s not so much the fuzzy picture or the tracking issues we miss, but the physical experience the physical medium brought to movie night. To recreate that magic, [Dillan] made a Modern VHS with NFC and ESPHome.

NFC tags are contained in handsomely designed 3D printed cartridges. You can tell [Dillan] put quite a bit of thought into the industrial design of these: there’s something delightfully Atari-like about them, but they have the correct aspect ratio to hold a miniaturized movie poster as a label. They’re designed to print in two pieces (no plastic wasted on supports) and snap together without glue. The printed reader is equally well thought out, with print-in-place springs for that all important analog clunk.

Electronically, the reader is almost as simple as the cartridge: it holds the NFC reader board and an ESP32. This is very similar to NFC-based audio players we’ve featured before, but it differs in the programming. Here, the ESP32 does nothing related directly to playing media: it is simply programmed to forward the NFC tag id to ESPHome. Based on that tag ID, ESPHome can turn on the TV, cue the appropriate media from a Plex server (or elsewhere), or do… well, literally anything. It’s ESPHome; if you wanted to make this and have a cartridge to start your coffee maker, you could.

If this tickles your nostalgia bone, [Dillan] has links to all the code, 3D files and even the label templates on his site. If you’re not sold yet, check out the video below and you might just change your mind. We’ve seen hacks from The Stock Pot before, everything from a rebuilt lamp to an elegant downspout and a universal remote.

Continue reading “Reliving VHS Memories With NFC And ESPHome” →