Based on details from this discord thread:
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Assure that HD hole on this disk is open
Run the Floppy tool on your MEGA65
Floppy tool d81 disk-image is available here:
Select option
6. Wipe disk
After disk is wiped, then cover the HD hole with some black gaffa tape (so that the drive will treat it as a DD disk)
NOTE: Place the tape on the undersideof the floppy disk (not on the
top side!)
Then back in BASIC, perform the
HEADER "name",I42
command to format the disk for use on your MEGA65
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