[manawyrm]

Depends on what you want to do :) If you just want to read/write sectors of 512 bytes at a time, it's pretty easy to implement even on a simple MCU.

There's a couple of registers which need to be set: https://wiki.osdev.org/ATA_PIO_Mode and you can then just read/write the data from the parallel lines.

Here's a similar project using an ATmega32: https://github.com/zwostein/idetrol (i used this code, ported to ARM to check my hardware before I wrote the kerneldriver)

[stefan_]

How can this be so easy but talking to an SD card is an impossible task without implementing a billion vendor/type quirks.

[myself248]

ATA was implemented by engineers and then described in a spec.

SD was designed by committee and then implemented as best they could.

[Galanwe]

Ooh the hours lost trying to reverse the proper call sequence and frequency for my SD card, thanks for the reminder.