Point of sale system having backup file device

摘要

A file control system includes a master terminal and a backup terminal, a plurality of satellite terminals, a master file and a backup file, and a file controller for each file. The master file responds to a request for price look up from any of the satellite terminals regardless of any operation of the master terminal or the backup terminal. The master file or the backup file acts or operates as the main operating file to update the system when the other file is down.