Hi James O,
The lpcopen code still use the older fatfs system.
Your code http://elm-chan.org/fsw/ff/res/app4.c should use the new fatfs, that's why you run it fails.
If you want to use the new app, you also need to modify the lpcopen fatfs file to the new fatfs lib.
We still don't have the updated version, so if you need it, you can try to replace the old fatfs system file with the newest lib file by yourself.
Wish it helps you!
Have a great day,
Kerry
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------