The Super Bass Station comes preloaded with 200 sounds. The first 50 programs ("A" bank 000 to 049) cannot be overwritten as these are stored in Read Only Memory. The remaining 150 memory locations ("A" bank 050 - 099 and "B" bank 100 - 199) are RAM locations. If necessary the factory sounds stored in the RAM locations can be recalled by holding the save & write buttons simultaneously while applying power to the Super Bass Station. The Super Bass Station stores user sounds in a memory device which does not require back up power, therefore the Super Bass Station does not have a back up battery.