So I created the... GPC MKII. With slightly mixed feelings. Hear me out...
The original GPC was kind of a joke, I didn't really plan on making more. But somehow it was popular enough to do so - and I was humbled by and grateful to the eccentric, kindly, patrons that bought one (particularly the good folks of /r/cassettefuturism).
And then enough interest to warrant a further run... but even in the context of being handmade, making more wasn't sustainable. Part of the joke was that it is not a computer at all - just a bunch of blinking LEDs wired up in parallel; such LEDs are THT, which means hand soldering. The first run had me doing approx 10,000 of them, which was... enough.
To make another run feasible required designing PCB that could be assembled with LEDs at the fabrication house... but that means regular, on-or-off LEDs. I realised - with a slightly heavy heart - that to match the MKI functionality (or lack thereof), I had to make it actually a computer. A 16Mhz, 8-bit, 2.5kb RAM computer (aka Arduino).
Try as I might, I could not resist some feature creep and added some additional modes... but stood my ground with the colours - no RGBs here, just 576 pure, warm, red and yellow LEDs.