A DIY mad scientist from Poland built his own CPU out of dozens of ancient memory chips

You might be reading this on a gaming PC you built yourself, but you probably can’t say you built the processor from scratch with your own hands and a soldering iron. One DIY enthusiast did just that in a project that’s an impressive look at how computers work, and how far they’ve come.

First reported by Tom’s Hardware, Polish computing YouTuber Majsterkowanie i nie tylko (MINT for short) posted a video on his channel earlier this month showing off a working homemade CPU built with retro parts inspired by 8-bit microprocessors from the early days of PCs. MINT even specifically mentions the Zilog Z80, which was one of the most popular processors of the late 1970s and even became an early laptop chip in the 1980s.

The whole project took 3 months to complete and stemmed from MINT’s interest in retro computers. As he explains in the video, which has been translated from Polish with the aid of AI: “It started with collecting a large amount of old memory chips. I started experimenting with them and quickly realized you can make some really cool things out of these seemingly useless really old things.”

Initially, MINT was just using those outdated memory chips for simple tasks, like controlling a motor or light dimmer. But eventually he figured out that by combining several memory chips, he might be able to make a fully-functioning 8-bit CPU.

Over the course of the half-hour long video, MINT lays out the lengthy process that went into accomplishing this. Not only did he build and solder the CPU himself, he even spent “hundreds of hours” writing the code for it. If you’re interested in the finer details of how computers work, MINT’s video is an interesting deep dive into all the components and how they interact with each other to execute commands.

The end result is the “EPROMINT CPU.” As a proof of concept, MINT hooked it up to a small VFD display and programmed it to play scenes from The Matrix. They obviously come through pixelated, but it works nonetheless.

As MINT put it: “It doesn’t require a team of people or a multi-million dollar budget to build, yet it’s a fully functional processor, and simple enough I can explain how it works.”