trainer

16 Articles

Scott and his Prompt 80

Restoring A Vintage Intel Prompt 80 8080 Microcomputer Trainer

September 3, 2025 by 3 Comments

Over on his blog our hacker [Scott Baker] restores a Prompt 80, which was a development system for the 8-bit Intel 8080 CPU.

[Scott] acquired this broken trainer on eBay and then set about restoring it. The trainer provides I/O for programming, probing, and debugging an attached CPU. The first problem discovered when opening the case is that the CPU board is missing. The original board was an 80/10 but [Scott] ended up installing a newer 80/10A board he scored for fifty bucks. Later he upgraded to an 80/10B which increased the RAM and added a multimodule slot.

[Scott] has some luck fixing the failed power supply by recapping some of the smaller electrolytic capacitors which were showing high ESR. Once he had the board installed and the power supply functional he was able to input his first assembly program: a Cylon LED program! Making artistic use of the LEDs attached to the parallel port. You can see the results in the video embedded below.

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Build A Super Cheap RC Trainer Plane With Foam

September 5, 2024 by 20 Comments

Once upon a time, RC planes were expensive models that took months to build and big money to equip with electronics. Since the 20th century though, powerful batteries have become cheap, as have servos and radio controllers. Combine them with a bit of old packing material and you can get a little RC trainer up and running for peanuts, as [Samm Sheperd] demonstrates.

[Samm] started referring to this as the “$5 trainer,” though he admits that it will cost more than that if you don’t have some bits and pieces laying around. He demonstrates how to cut cheap foamboard with a hot guitar string, and how to form it into a viable wing. That’s the most crucial part, with the fuselage and tail surfaces relatively simple by comparison. With that complete, it’s as simple as bolting on a motor, some servos, and control horns, and you’re up and running. You can even whip up a landing gear if you’re so inclined! Then, figure out your center of gravity, get it right, and then you’re pretty much ready to fly.

It’s a great primer on how to build a basic RC model, and if you do it right, it should have pretty forgiving handling, too. Plus, it’s so cheap that it should be easy to repair if you crash. Happy modelling! Video after the break.

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Learning Morse Code With A DIY Trainer

June 22, 2024 by 18 Comments

Morse code, often referred to as continuous wave (CW) in radio circles, has been gradually falling out of use for a long time now. At least in the United States, ham radio licensees don’t have to learn it anymore, and the US Coast Guard stopped using it even for emergencies in 1999. It does have few niche use cases, though, as it requires an extremely narrow bandwidth and a low amount of power to get a signal out and a human operator can usually distinguish it even if the signal is very close to the noise floor. So if you want to try and learn it, you might want to try something like this Morse trainer from [mircemk].

While learning CW can be quite tedious, as [mircemk] puts it, it’s actually fairly easy for a computer to understand and translate so not a lot of specialized equipment is needed. This build is based around the Arduino Nano which is more than up for the job. It can accept input from any audio source, allowing it to translate radio transmissions in real time, and can also be connected to a paddle or key to be used as a trainer for learning the code. It’s also able to count the words-per-minute rate of whatever it hears and display it on a small LCD at the front of the unit which also handles displaying the translations of the Morse code.

If you need a trainer that’s more compact for on-the-go CW, though, take a look at this wearable Morse code device based on the M5StickC Plus instead.

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3D Printed Braille Trainer Reduces Barrier To Entry

May 20, 2024 by 8 Comments

Accessibility devices are a wonder of modern technology, allowing people with various needs to interact more easily with the world. From prosthetics to devices to augment or aid someone’s vision or hearing, devices like these can open up many more opportunities than would otherwise exist. A major problem with a wide array of these tools is that they can cost a fortune. [3D Printy] hoped to bring the cost down for Braille trainers which can often cost around $1000.

Braille trainers consist of a set of characters, each with six pins or buttons that can be depressed to form the various symbols used in the Braille system. [3D Printy]’s version originally included six buttons, each with a set of springs, that would be able to pop up and down. After some work and real-world use, though, he found that his device was too cumbersome to be effective and redesigned the entire mechanism around flexible TPU filament, allowing him to ditch the springs in favor of indentations and buttons that snap into place without a dedicated spring mechanism.

The new design is modular, allowing many units to be connected to form longer trainers than just a single character. He’s also released his design under the Creative Commons public domain license, allowing anyone to make and distribute these tools as they see fit. The design also achieves his goal of dramatically reducing the price of these tools to essentially just the cost of filament, provided you have access to a 3D printer of some sort. If you need to translate some Braille writing and don’t want to take the time to learn this system, take a look at this robotic Braille reader instead.

Thanks to [George] for the tip!

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A Retro-Style Trainer For Motorola’s 1-Bit Chip

March 11, 2023 by 6 Comments

If you want to program a microcontroller today, you pop open your editor of choice, bang out some code, and flash it over USB. But back in ancient times, when your editor was a piece of paper and you didn’t even have a computer of your own, things were a bit different. In that case, you might have reached for a “trainer”: a PCB that included the chip you wanted to program along with an array of switches, LEDs, and maybe even a hex keypad for good measure. Grab yourself the programming manual (printed on paper, naturally), and you’re good to go.

So when [Nicola Cimmino] became curious about the Motorola MC14500, a 1-bit ICU (Industrial Control Unit) from the 1970s, he could think of no more appropriate way to get up close and personal with the chip than to design an era-appropriate trainer for it. The resulting board, which he’s calling the PLC14500 Nano, is festooned with LEDs that show the status of the system buses and registers. Thanks to the chip’s single-step mode, this gives you valuable insight into what’s happening inside this piece of classic silicon.