A multifunction device includes a plurality of slots capable of accepting the insertion of media. Initially, the multifunction device is set to a single drive mode (automatic switching mode) and subsequently is set to a multi-drive mode upon receiving a GET_MAX_LUN command from a personal computer. In the single drive mode, a drive is assigned only to one slot in which a medium has been first inserted. In the multi-drive mode, drives are assigned for all of the slots respectively.