View on GitHub

retro-computing

🤓🕹💾 This hobby project contains software implementations of old microprocessors and complete computer systems. I'm very interested in retrocomputing and this is how I learn about the inner workings of these old, classic and amazing computers and game consoles.

MOS Technology 6502 8-bit microprocessor

“The 6502 and variations of it is used in many of the old home video game consoles and computers, such as the Atari 2600, Atari 8-bit family, Apple II, Nintendo Entertainment System, Commodore 64, Atari Lynx, BBC Micro and others.”

I’ve always wanted to write my own implementation of this legendary chip and that’s why this project exists. The main goal was to get the 6502-implementation working and being able to run Commodore 64 BASIC on it.

I implemented the 6502 in about a weeks worth of late nights, including testing and bug fixes. I tried to use original and reverse engineered documentation rather than looking at other software implementations so that I would learn as much as possible about every part of the chip. I did however look up logic from different software implementations when I had specific bugs that I couldn’t figure out after spending a lot of time debugging.

Features / Roadmap