Spectravideo Computers Get A Big Upgrade

November 5, 2025 by Lewin Day 2 Comments

Spectravideo is not exactly the most well-known microcomputer company, but they were nevertheless somewhat active in the US market from 1981 to 1988. Their computers still have a fanbase of users and modders. Now, as demonstrated by [electricadventures], you can actually upgrade your ancient Spectravideo machine with some modern hardware.

The upgrade in question is the SVI-3×8 PicoExpander from [fitch]. It’s based on a Raspberry Pi Pico 2W, and is built to work with the Spectravideo 318 and 328 machines. If you’re running a 328, it will offer a full 96kB of additional RAM, while if you’re running a 318, it will add 144 kB more RAM and effectively push the device up to 328 spec. It’s also capable of emulating a pair of disk drives or a cassette drive, with saving and loading images possible over Wi-Fi.

It’s worth noting, though, that the PicoExpander pushes the Pico 2W well beyond design limits, overclocking it to 300 MHz (versus the original 150 MHz clock speed). The makers note it is “bleeding edge” hardware and that it may not last as long as the Spectravideo machines themselves.

Design files are available on Github if you want to spin up your own PicoExpander, or you can just order an assembled version. We’ve seen a lot of other neat retrocomputer upgrades built around modern hardware, too. Video after the break.

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MCE Blaster Translates TTL For Modern(ish) Monitors

November 3, 2025 by Tyler August 15 Comments

VGA isn’t much used anymore, but it’s not hard to get a hold of monitors with that input. How about the older standards like EGA, CGA, or MDA? Well, it’s good luck on eBay or at the recycling yard to get a period-appropriate monitor, but the bulky, fragile CRTs seem to have been less likely to survive than computers that drove them. That’s what [Scrap Computer]’s MCE Blaster is for: it sits betwixt the retrocomputer’s TTL output and the VGA input of a (more) modern monitor, be it CRT or LCD.

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Waverider: Scanning Spectra One Pixel At A Time

October 13, 2025 by Matt Varian 15 Comments

Hyperspectral cameras aren’t commonplace items; they capture spectral data for each of their pixels. While commercial hyperspectral cameras often start in the tens of thousands of dollars, [anfractuosity] decided to make his own with the Waverider.

To capture spectral data from every pixel location in the camera, [anfractuosity] first needed a way to collect that data — for that, he used an AFBR-S20M2WV, a miniature USB spectrometer he picked up second-hand. This sensor allows for the collection of data from 225 nm all the way up to 1000 nm. Of course, the sensor can only do that for one single input, so to turn it into a camera, [anfractuosity] added a stepper-driven x-y stage controlled by a Raspberry Pi Pico and some TMC2130 stepper drivers.

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Debugging The Instant Macropad

August 25, 2025 by Al Williams No comments

Last time, I showed you how to throw together a few modules and make a working macropad that could act like a keyboard or a mouse. My prototype was very simple, so there wasn’t much to debug. But what happens if you want to do something more complex? In this installment, I’ll show you how to add the obligatory blinking LED and, just to make it interesting, a custom macro key.

There is a way to print data from the keyboard, through the USB port, and into a program that knows how to listen for it. There are a few choices, but the qmk software can do it if you run it with the console argument.

The Plan

In theory, it is fairly easy to just add the console feature to the keyboard.json file:

{
...
    "features": {
        "mousekey": true,
        "extrakey": true,
        "nkro": false,
        "bootmagic": false,
        "console": true
    },
...

That allows the console to attach, but now you have to print.

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Instant Macropad: Just Add QMK

August 20, 2025 by Al Williams 2 Comments

I recently picked up one of those cheap macropads (and wrote about it, of course). It is surprisingly handy and quite inexpensive. But I felt bad about buying it. Something like that should be easy to build yourself. People build keyboards all the time now, and with a small number of keys, you don’t even have to scan a matrix. Just use an I/O pin per switch.

The macropad had some wacky software on it that, luckily, people have replaced with open-source alternatives. But if I were going to roll my own, it would be smart to use something like QMK, just like a big keyboard. But that made me wonder, how much trouble it would be to set up QMK for a simple project. Spoiler: It was pretty easy.

The Hardware

Simple badge or prototype macropad? Why not both?

Since I just wanted to experiment, I was tempted to jam some switches in a breadboard along with a Raspberry Pi Pico. But then I remembered the “simple badge” project I had up on a nearby shelf. It is simplicity itself: an RP2040-Plus (you could just use a regular Pi Pico) and a small add-on board with a switch “joystick,” four buttons, and a small display. You don’t really need the Plus for this project since, unlike the badge, it doesn’t need a battery. The USB cable will power the device and carry keyboard (or even mouse) commands back to the computer.

Practical? No. But it would be easy enough to wire up any kind of switches you like. I didn’t use the display, so there would be no reason to wire one up if you were trying to make a useful copy of this project.

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The PC In Your Pico

August 18, 2025 by Jenny List 34 Comments

We’re all used to emulating older computers here, and we’ve seen plenty of projects that take a cheap microcontroller and use it to emulate a classic home computer or gaming platform. They’re fun, but serve mostly as a way to relive old toys.

As microcontrollers become faster though it’s inevitable that the machines they can emulate become more powerful too, so we’re moving into the realm of emulating productivity machines from years past. An example is [Ilya Maslennikov]’s pico-286, which as its name suggests, is a 286 PC emulator for the Raspberry Pi Pico.

It has an impressive set of sound and video card emulations, can drive either a VGA or an HDMI monitor, and uses a PS/2 keyboard and mouse. If DOS games are your thing it should provide what you want, but it’s caught our eye because there was a time when a 286 DOS PC was a productivity machine. There’s a huge library of still-useful software for DOS, and thus the prospect of a handheld DOS PC still has some appeal. We’d love to see someone put this in a badge.

MS-DOS may no longer be for sale, but there are several ways to land an open-source DOS in 2025. FreeDOS is something of a powerhouse.

Keyboard Hero: A Barebones Alternative To The Guitar Version

August 3, 2025 by Lewin Day 8 Comments

Guitar Hero was all the rage for a few years, before the entire world apparently got sick of it overnight. Some diehards still remember the charms of rhythm games, though. Among them you might count [Joseph Valenti] and [Daniel Rodriguez], who built a Keyboard Hero game for their ECE 4760 class at Cornell.

Keyboard Hero differs quite fundamentally from Guitar Hero in one major way. Rather than having the player tackle a preset series of “notes,” the buttons to press are instead procedurally generated by the game based on incoming audio input. It only works with simple single-instrument piano music, but it does indeed work. A Raspberry Pi Pico is charged with analyzing incoming audio and assigning the proper notes. Another Pi Pico generates the VGA video output with the game graphics, which is kept in sync with the audio pumped out from the first Pico so the user can play the notes in time with the music. Rather than a guitar controller, Keyboard Hero instead relies on five plastic buttons assembled on a piece of wood. It works.

It’s obviously not as refined as the game that inspired it, but the procedural generation of “notes” reminds us of old-school rhythm game Audiosurf. Video after the break.

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