Yamaha Electone EL-900 Owner's Manual page 86

Turning the Electone off erases all panel settings you have made. When
the Electone is turned on, Basic Registration 1 is automatically selected.
If you have made panel settings you wish to keep, save them to Registration
Memory before turning the Electone off.
You can, however, restore the panel settings that were made before the
Electone was last turned off. In doing this, first be careful NOT to press
any panel buttons (excepting those in Basic Registration) after you turn
the Electone back on. Then, to restore the previous settings, hold down
the M./TO DISK (Memory) button and press D. (Disable) button.
M.
13 14 15 16 1 2 3 4 5 6 7 8 9 10 11 12 D.
/TO DISK
6
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