Abstract: An electronic cash register includes thirty department keys for identifying the department of the commodity purchased by the customer. A department memory has ninety memory sections each of which stores the unit cost information and the total amount of the transaction related to the commodity of a specific department. Three department level keys are provided to divide the department memory into three groups. When the first department level key is selected, the thirty department keys correspond to the first through thirtieth memory sections in the department memory. When the second department level key is selected, the thirty department keys correspond to thirty-first through sixtieth memory sections. When the third department level key is selected, the sixty-first through ninetieth memory sections correspond to the thirty department keys.

Abstract: An electronic cash register comprising a volatile memory for the storage of data concerned with cash registration, a writable non-volatile memory for the storage of the data, and a control for writing the data in the non-volatile memory. The contents stored in the volatile memory can be corrected, if necessary, on the basis of the data stored in the non-volatile memory.