Thank you for asking!
To the best of my recollection the file system on my micro SD chip is the original file system and the chip came formatted. I do occassionally reformat a chip, but when I do it would almost certainly be in ext4 format. I can mount the chip on my Linux systems when I mount and view with:
mount -t vfat …
The music on the chip was copied from my Linux system.
I assume vfat is equivalent to FAT32, but I cannot gaurantee that as a fact.
Jim A.
