Split Flap Display Tells Us The Word

LED and LCD displays are a technological marvel. They’ve brought the price of televisions and monitors down to unheard-of levels since the days of CRTs, but this upside arguably comes with an aesthetic cost. When everything is covered in bland computer screens, the world tends to look a lot more monotonous. Not so several decades ago when there were many sharply contrasting ways of displaying information. One example of this different time comes to us by way of this split-flap display that [Erich] has been recreating.

Split-flap displays work by printing letters or numbers on a series of flaps that are attached to a spindle with a stepper motor. Each step of the motor turns the display by one character. They can be noisy and do require a large amount of maintenance compared to modern displays, but have some advantages as well. [Erich]’s version is built out of new acrylic and MDF, and uses an Arduino as the control board. A 3D printer and CNC machine keep the tolerances tight enough for the display to work smoothly and also enable him to expand the display as needed since each character display is fairly modular.

Right now, [Erich]’s display has 20 characters on two different rows and definitely brings us back to the bygone era where displays of this style would have been prominent in airports and train stations. This display uses a lot of the basics from another split flap display that we featured a few years ago but has some improvements. And, if you’d prefer restorations of old displays rather than modern incarnations, we have you covered there as well.

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A Ryobi belt sander with remote control car parts

Boring Belt Sander Is RC Racer In Disguise

As a child, [David Windestal] already knew that a belt sander was the perfect motor for a banging radio-controlled car. Many years later, the realization of that dream is everything he could have hoped for.

The core of this project is a battery-powered belt sander by a well known manufacturer of gnarly yellow power tools. With an eye for using bespoke 3D printed parts, the conversion appeared straightforward – slap on (or snap on) a pre-loved steering mechanism, add a servo for controlling the sander’s trigger, and that’s pretty much job done. Naturally the intention was to use sandpaper as tread, which is acceptable for outdoor use but not exactly ideal for indoors. A thermoplastic polyurethane (TPU) tread was designed and printed for playtime on the living room floor, where sandpaper may be frowned upon.

The finished product is a mean looking toy with plenty of power. What we really like most about this hack is the commitment to the aesthetics. It’s seriously impressive to see a belt sander so convincingly transformed into a three-wheeler radio-controlled car. The final iteration is also completely reversible, meaning that your belt sander can keep on sanding two by fours on the job site. All the printed parts snap snug into place and are mostly indistinguishable from the stock sander.

Speaking of reversible, there were just a couple of issues with the initial design, if you catch our drift. We won’t spoil what happens, but make sure to watch the video after the break for the full story.

If this hack has whet your appetite for more quirky tool hacks, make sure to check out our coverage of the angle grinder turned slimline belt sander. Or if you can’t get enough of RC, then check out this remote controlled car with active suspension.

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A vintage pocket calculator with extra exposed circuitry added

I2C Breathes New Life Into Casio Pocket Calculator

When is a pocket calculator more than just a calculator? [Andrew Menadue] has been pushing the limits of his 1970s Casio FX-502P by adding all sorts of modern functionality via the calculator’s expansion port.

Several older Casio calculators included an expansion port for connecting cassette tape storage and printing functionality. Data on the FX-502P could be saved on cassette tape using the well-known Kansas City standard, however this signal was produced by Casio’s FA-1 calculator cradle, not the FX-502P itself. To interact with the calculator itself would require an understanding of whatever protocol Casio designed for this particular model.

It turns out that the protocol is a little quirky compared to its contemporaries, with variable length data packets and inverted data logic, (zero volts is ‘1’ and three volts is ‘0’). Once the protocol was untangled, it was ‘simply’ a matter of connecting the calculator to the GPIO interface on the STM32, and using some software wizardry to start shooting data packets back and forth.

This hack can be used to send and receive data from an SD card (via a RAM buffer), however it’s the other expansion capabilities that really make us wonder. [Andrew] has demonstrated how easy it is to add a real-time clock or thermal printer. Using the I2C capabilities of the STM32, it’s likely that all sorts of gadgets and sensors could be coupled with this vintage calculator, and many others like it.

You can find even more details about this hack over here, including some follow up videos to the original hack. No stranger to vintage calculators, we last featured [Andrew] after he retrofitted a modern LCD display to an old Casio. It’s charming to see how these calculators are far from obsolete.

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It’s Bad Apple, But On A 32K EPROM

The Bad Apple!! video with its silhouette animation style has long been a staple graphics demo for low-end hardware, a more stylish alternative to the question “Will it run DOOM?”. It’s normal for it to be rendered onto a screen by a small microcomputer or similar but as [Ian Ward] demonstrates in an unusual project, it’s possible to display the video without any processor being involved. Instead he’s used a clever arrangement involving a 32K byte EPROM driving a HD44780-compatible parallel alphanumeric LCD display.

While 32K bytes would have seemed enormous back in the days of 8-bit computing, even when driving only a small section of an alphanumeric LCD it’s still something of a struggle to express the required graphics characters. This feat is achieved by the use of a second EPROM, which carries a look-up table.

It’s fair to say that the result which can be seen in the video below the break isn’t the most accomplished rendition of Bad Apple!! that we’ve seen, but given the rudimentary hardware upon which it’s playing we think that shouldn’t matter. Why didn’t we think of doing this in 1988!

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PS2 Memory Card ISO Loader Offers Classic Gaming Bliss

It used to be that to play a console game, you just had to plug in a cartridge or put a CD/DVD in the optical drive. But these days, with modern titles ballooning up to as much as 100 GB, you’ve got no choice but to store them on the system’s internal hard disk drive. While that can lead to some uncomfortable data management decisions, at least it means you don’t have to get up off the couch to switch games anymore.

Which is precisely why the MC2SIO project for the PlayStation 2 is so exciting. As [Tito] explains in his latest
Macho Nacho Productions video, this simple adapter lets you connect an SD card up to the console’s Memory Card slots and use that to hold ISOs of your favorite games. With the appropriate homebrew software loaded up, your PS2 becomes a veritable jukebox of classic games.

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Tiny TV Celebrates The Forgotten Tech Of CRTs

For those of us who grew up before the Internet, the center of pretty much every house was the TV. It was the shrine before which we all worshipped, gathering together at the appointed times to receive the shared wisdom of mass entertainment. In retrospect, it really wasn’t that much. But it’s what we had.

Content aside, one thing all these glowing boxes had in common was that which did the glowing — the cathode ray tube (CRT). Celebrating the marvel of engineering that the CRT represents is the idea behind [Matt Evan]’s tiny desktop TV. The design centers around a 1.5″ CRT that once served as a viewfinder on a 1980s-vintage Sony camcorder. [Matt] salvaged the tube and the two PCB assemblies that drive it, mounting everything in a custom-built acrylic case, the better to show off the bulky but beautiful tube.

The viewfinder originally used a mirror to make the optical path more compact; this forced [Matt] to adapt the circuit to un-reverse the image for direct viewing. Rather than receiving analog signals off the air as we did in the old days — and we liked it that way! — the mini monitor gets its video from a Raspberry Pi, which is set to play clips of TV shows from [Matt]’s youth. Rendered in glorious black and white and nearly needing a magnifying glass to see, it almost recaptures the very earliest days of television broadcasting, when TVs all had screens that looked more like oscilloscope CRTs.

This project is a nice homage to a dying technology, and [Matt] says it has spurred more than one conversation from people you grew up knowing only LCD displays. That’s not to say CRTs are totally dead — if you want to build your own old-school TV, there’s a kit for that.

Build Your Own CRT TV

There was a time following the Second World War when TV sets for the nascent broadcast medium were still very expensive, but there was an ample supply of war-surplus electronic parts including ex-radar CRTs. Thus it wasn’t uncommon at all for electronics enthusiasts of the day to build their own TV set, and magazines would publish designs to enable them. With a burgeoning consumer electronics industry the price of a new TV quickly dropped to the point of affordability so nobody would consider building one themselves today. Perhaps that should be amended to almost nobody, because [Retro Tech or Die] has assembled a small black-and-white CRT TV from a kit he found on AliExpress.

We have to admit to having seen the same kit and despite a sincere love for analogue telly, to have balked at the price. It’s an exceptionally cheap set of the type that was available from discount stores for a laughably low price around the final few years of mainstream analogue TV broadcasting, and having a couple in the stable we can confirm that the value here lies in building the thing rather than owning it.

The unboxing and building proceeds as you might expect, with the addition of very poor documentation and extremely low-quality parts. Satisfyingly it works on first power-up, though some adjustment and the reversing of a deflection yoke connection is required for a stable picture. The scanned area doesn’t fill the screen and he doesn’t find the solution in the video, we hope that by his next video someone will have suggested moving the deflection yoke forwards.

Perhaps merely assembling a kit might not seem the most exciting subject for a Hackaday story, but this one is a little different here in 2022. CRT TV sets are now a long-gone anachronism, so for a younger generation there is very little chance to see them up close and thus watching one built has some value. If you want to spend the cash and build your own he’s dropped the link in the YouTube description, otherwise watch the progress in the video below the break.

Fancy learning a bit more about analogue TV? Have a dive into the video waveform. Or for a bit more CRT goodness, learn about converging a delta-gun colour set from the days when a TV weighed almost as much as you did.

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