Roland FP-4 Owner's Manual page 61

Saving the Registration Set
5. Press the [Rec] button.
The registration set will be saved.
NOTE
Never turn off the power while settings are being saved. If you do so, the FP-4's
internal memory will be destroyed, rendering it unusable.
You can return the content saved at a [Registration] button to the factory-set condition.
Refer to "Restoring the Factory-set Condition (Factory Reset)" (p. 91).
To recall the saved performance settings, refer to "Loading a Registration Set You
Saved" (p. 62).
Saving Your Favorite Performance Settings
61