August 11, 2026
8-bit dreams, flat-pack shame
Programming the Gigatron
A retro computer deep-dive sparks nostalgia, guilt, and unbuilt-kit confessions
TLDR: A fan made an unofficial, easier-to-follow guide to programming the Gigatron, a quirky retro computer built from simple parts. The comments stole the show with nostalgic stories and one painfully relatable confession: people love this machine, but some are still staring at unbuilt kits years later.
A hobbyist’s attempt to decode and explain the quirky Gigatron — a homemade-style color computer built from simple chips — could have been a dry, ultra-technical project. Instead, the real emotional plot twist came from the community, where the loudest reaction wasn’t "wow, nice instruction table," but "oh no, this reminded me of my own unfinished project." That’s the kind of retro-tech drama money can’t buy.
The article itself is a patient effort to make sense of how this unusual machine works, translating its behavior into something closer to readable pseudo-code and warning readers that it’s unofficial and might go out of date. In plain English: someone did the hard work of turning a mysterious old-school computer brain into a guide normal humans can actually follow. But the comments instantly shifted the mood from pure geekery to bittersweet nostalgia.
The standout comment came from bananaboy, who casually dropped a mini soap opera: they bought a Gigatron kit years ago, just after one of its original creators, Marcel, passed away, and around the time the other creator, Walter, was shipping what may have been some of the last kits. The twist? They still haven’t built it. The confession landed with big “retro collector guilt” energy — part heartfelt tribute, part "my beautiful wooden case is also a monument to procrastination." There’s no huge flame war here, but there is delicious low-stakes drama: admiration for the machine, sadness over its history, and the universal hobbyist shame of owning a cool kit that’s still sitting in a box.
Key Points
- •The article is an unofficial personal technical page about understanding and programming the Gigatron TTL Color Micro-computer using files from the kervinck/gigatron-rom GitHub repository.
- •The Gigatron CPU is described as an 8-bit processor with Harvard architecture, a 14-bit program counter, a 15-bit RAM range, three 8-bit registers, and 8-bit input/output.
- •The article states that ROM is only used for storing instructions and cannot be directly accessed through CPU instructions, though a workaround to read ROM data is mentioned.
- •The author rewrote the gtemu.c emulator to output instruction behavior in pseudo-C and used that process to build an instruction table.
- •The instruction documentation covers arithmetic, logical, memory, output, and branch operations, and notes that RAM access is clipped to 0x7fff and the program counter normally increments unless an instruction changes it.