casio

41 Articles

A Casio Toy Synth Is Ready To ROCK!

October 11, 2025 by 4 Comments

There is likely to be more than one of you who has eyed up a child’s toy synthesizer in a second hand store, and considered making something more impressive with it. In many cases these instruments are underwhelming, having a very small subset of functions based into their black-epoxy-blob microcontrollers.

[Make Something] found a Casio toy synth that has a few more functions than the average model, and with the addition of some extra effects electronics and a beautifully made case, turned it into an altogether more interesting instrument.

Most of the video has an element of workshop porn about it, as he makes a very nice Moog-style console case for it, a task made easier by an impressive array of CNC tools. The electronics are slightly more interesting, being a selection of cheap guitar pedals gutted and combined with a cheap tube preamp board. The result is a machine capable of some far more interesting sounds

We think many Hackaday readers would be able to repeat these functions from scratch without the pedals, and while the case is a thing of beauty it’s likely a decent job could be done with a little less finesse on more commonplace tools. Perhaps it’s worth giving those toy synths a second look, because they really can be had for pennies if you look hard enough. Perhaps it’s an easier option than a previous toy musical upgrade.

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Calculator Battery Mod Lets You Go The Distance

September 23, 2025 by 23 Comments

Disposable batteries seem so 1990s. Sure, it’s nice to be able to spend a couple of bucks at the drugstore and get a flashlight or TV remote back in the game, but when the device is a daily driver, rechargeable batteries sure seem to make more financial sense. Unfortunately, what makes sense to the end user doesn’t always make sense to manufacturers, so rolling your own rechargeable calculator battery pack might be your best option.

This slick hack comes to us from [Magmabow], who uses a Casio FXCG50 calculator, a known battery hog. With regular use, it goes through a set of four alkaline AA batteries every couple of months, which adds up quickly. In search of a visually clean build, [Magmabow] based the build around the biggest LiPo pillow-pack he could find that would fit inside the empty battery compartment, and planned to tap into the calculator’s existing USB port for charging. A custom PCB provides charging control and boosts the nominal 3.7-volt output of the battery to the 5-ish volts the calculator wants to see. The PCB design is quite clever; it spans across the battery compartment, with its output feeding directly into the spring contacts normally used for the AAs. A 3D-printed insert keeps the LiPo and the PCB in place inside the battery compartment.

Almost no modifications to the calculator are needed, other than a couple of bodge wires to connect the battery pack to the calculator’s USB port. The downside is that the calculator’s battery status indicator won’t work anymore since the controller will just shut the 5-volt output down when the LiPo is discharged. It seems like there might be a simple fix for that, but implementing it on such a small PCB could be quite a challenge, in which case a calculator with a little more room to work with might be nice. Continue reading “Calculator Battery Mod Lets You Go The Distance” →

A Label Printer Gets A New Brain

September 1, 2025 by 9 Comments

The internals of a printer, whatever technology it may use, are invariably proprietary, with an abstracted more standard language being used to communicate with a host computer. Thus it’s surprisingly rare to see hacks on printers as printers, rather than printer hacks using the parts for some other purpose. This makes [Oelison]’s brain-swap of a Casio thermal label printer a welcome surprise, as it puts an ESP32 in the machine instead of whatever Casio gave it.

The value in the hack lies in the insight it gives into how a thermal printer works as much as it does in the ESP32 and the Casio, as it goes into some detail on the various signals involved. The strobe line for instance to enable the heater is a nuance we were unaware of. The resulting printer will lose its keyboard and display, but  make up for it in connectivity.

Despite what we said earlier this isn’t the first label printer hack we’ve seen. A previous one was Linux-based though.

Teardown Of Casio Credit Card-Sized Radio

March 26, 2025 by 33 Comments

These days we don’t get too fussed about miniaturized electronics, not when you can put an entire processor and analog circuitry on a chip the size of a grain of sand. Things were quite different back in the 1980s, with the idea of a credit card-sized radio almost preposterous. This didn’t stop the engineers over at Casio from having a go at this and many other nutty ideas, with [Matt] from Techmoan having a go at taking one of these miniaturized marvels apart.

The Casio FM Stereo radio in happier days. (Credit: Techmoan, YouTube)

On the chopping block is the FM stereo device that was featured in a previous episode. Out of the four credit card-sized radios in that video, the one with the rechargeable battery (obviously) had ceased to work, so it was the obvious choice for a teardown. This mostly meant peeling off the glued-on top and bottom, after which the circuitry became visible.

In addition to the battery with a heavily corroded contact, the thin PCB contains a grand total of three ICs in addition to the analog circuitry. These were identified by [Spritetm] as an AM/FM tuner system IC (TA7792), an FM PLL MPX (TA7766AF) and a headphone amplifier (TA7767F), all of them manufactured by Toshiba.

Although [Matt] reckons this was a destructive teardown, we’re looking forward to the repair video where a fresh cell is soldered in and the case glued back together. Continue reading “Teardown Of Casio Credit Card-Sized Radio” →

Card Radios Remembered

March 22, 2025 by 18 Comments

We know how [Techmoan] feels. In the 1980s we had a bewildering array of oddball gadgets and exciting new tech. But as kids we didn’t have money to buy a lot of what we saw. But he had a £5 note burning a hole in his pocket from Christmas and found a Casio RD-10 “card radio” on sale and grabbed it. He’s long-ago lost that one, but he was able to find a new old stock one and shows us the little gadget in the video below.

The card-thin (1.9 mm) FM radio had many odd features, especially for the 1980s. For one thing, it took a coin cell, which was exotic in those days. The headphones had a special flat connector that reminded us of an automotive fuse. Even the idea of an earbud was odd at that time.

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Cutting Board Keyboard

February 17, 2025 by 4 Comments

Doesn’t this look fantastic? Hard to believe it, but the base of this keyboard began life as a cutting board, and there’s a gallery to prove it. This is actually [androidbrick]’s second foray into this type of upcycling.

This time, [androidbrick] used a FiiO KB3 and replaced the bottom half of the plastic shell with a hand-routed kitchen cutting board. The battery has been disabled and it works only in wired mode, which is fine with me, because then you get to use a curly cord if you want.

A lovely keyboard built into a kitchen cutting board.
Image by [androidbrick] via reddit
The switches are mostly Gateron EF Currys, though [androidbrick] left some of the original Gateron G Pro 3.0 on the stabilized keys just for comparison. As you might imagine, the overall sound is much deeper with a wooden bottom. You can check out the sound test on YouTube if you’d like, though it’s pretty quiet, so turn it up.

Those keycaps look even nicer from top-down, which you’ll see in the sound test video linked above. Just search ‘JCM MOA GMK’ on Ali and you’ll find them in a bunch of colorways for around $20. Apparently, [androidbrick] was saving them for months, just waiting for this build.

Via reddit

Continue reading “Keebin’ With Kristina: The One With The Cutting Board Keyboard” →

Casio Calculator Gets New Keyboard

February 1, 2025 by 6 Comments

What do you do with a circa 1985 Casio FX-451 calculator with a bad keyboard? Well, if you are [Poking Technology], you transplant the inside of the calculator to a new custom keyboard. There are two videos that cover the process in detail, which you can watch below.

The calculator has a unique design. It looks like a simple calculator in a wallet. But the wallet opens to reveal an extended keyboard with all the scientific features onboard. Unsurprisingly, the membrane keys didn’t survive over four decades. Disassembling the unit was a challenge. Soldering wires to the keyboard lines was further complicated by the fact that some of the lines are on the back of the PCB and pass through to the top under the main IC.

The new keyboard is quite a bit larger than the original, making this more of a desk calculator, but that also means you can use high-quality keys. We’d love to see a 3D printed case to wrap it all up, but the bare PCB look has its charms, too.

If you can’t understand how [Poking] can love a calculator so much, you probably never owned an HP-41C, either. Of course, our retro calculator dreams also include Star Trek.

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