A data storage system is provided for storing and retrieving data. The system includes: a conveyor system for carrying a plurality of data cartridges; and, a plurality of independently operable drive mechanisms, each one having a data cartridge transfer mechanism. The conveyor system is adapted to position a selected one of the data cartridges to the transfer mechanism of a selected one of the drive mechanisms. When so positioned, the transfer mechanism removes the data cartridge and inserts it into the drive mechanism for processing (i.e., data may be written onto the data cartridge or data may be read from the data cartridge). The data cartridge may then be withdrawn from the drive mechanism after processing and returned to the conveyor system. Because each one of the drive mechanisms is operable independently of the other drives and each drive has its own transfer mechanism, more than one data cartridge may be processed during the same time period, or during overlapping time periods.