A low cost data storage and communication system. The low cost data storage and communication system has a host and at least one card connected to the host. A voltage negotiator located in the system for determining a common operating voltage range that is a common demonminator of all independent operating voltage ranges of all of the cards connected to the system. In addition, there is a novel feature of partitioning the memory storages of the card. This feature provides the host the ability to simultaneously erase any combination of sectors in a single erase group, or any combination of the entire erase groups. Another feature feature provided by this novel method of partitioning the memory storages is the ability to write protect any combination of memory groups in the card.