Forked from https://github.com/gfoot/sdcard6502/ and modified to work with my PAL-1. Code can be assembled with ca65.

How to read and write SD cards with a 6532, step by step

This guide shows how to connect up an SD card reader to a PAL-1 6502 and use it to read/write data from SDHC cards.

The tutorial ends with being able to read arbitrary sectors from the SDHC card. Beyond that, I've included library-style code that can read/write from a FAT32 filesystem, with some example programs. For more information on this library code, see FAT32 Library Documentation

I'm only covering SDHC cards. You pretty much can't buy older/smaller cards these days, and not bothering to support the older protocol simplifies the code quite a bit.

Contents

Intro

• 0a Prerequisites and References
• 0b About the Sample Code
• 0c Initial Hardware Setup

Samples

• 1 Reading and Writing Bytes

• 2 Encaplusated sd_sendcommand

• 3 Complete Initialization Sequence

• 4 Reading Sectors

• 6 Reading File Content

  

Appendices

• A Next Steps
• B Older SD/MMC Cards