IMG decoder

This website has been succeeded by a standalone program called
Yamaha Electone Floppy Backup
You can download it here (as well a 64-bits version as a 32-bits version).
This program has more options and works better then the tool on this site, but you can still use this site.

Start with selecting your IMG file and
then follow the steps from top to bottom
a child can do the laundry...