This project is starting out as a step-by-step guide to reading SD cards from a homebrew 6502 computer like Ben Eater's, based on how I've done that in my own computer so far, and I'll try to keep it up-to-date in future as I add new functionality on top of that initial layer as well.

My goals here are initially simplicity and straightforwardness, rather than speed and efficiency, though I do plan to explore efficiency later on when the basics are clear.

This is not intended to definitively document the protocols etc - I'm giving references to good quality existing documents for that. It's more of a commentary about the processes and pitfalls I found along the way, with reference to my own tutorial/sample code and simple wiring guidance that's tailored for 6502-based systems.

There are also other 6502-based projects out there doing this, and you may want to search for those and consider following in their footsteps instead.