Sharp ZQ-6100M Operation Manual page 128

Forgotten Passwords
If you have forgotten the password and simply cannot remember it,
there is no choice but to delete the password along with all MARK*ED
entries.
Deleting all secret entries
Select DATA DELETION from the function menu.
FUNCTION] 3
Select SECRET DATA, and press to go ahead and delete all
secret entries along with the password. Press any other key to cancel
the deletion and leave all entries unchanged.
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