Abstract: A reading device for reading identification information of cartridges comprises a judging circuit for judging whether the cartridge has an identification information storer for storing the identification information of a recording medium thereof, and an information reader for reading the identification information of the identification information storer. This judgment is made before the information reader reads the identification information of the identification information storer, and the information reader reads the identification information only in the event that the cartridge has an identification information storer. Accordingly, waste of time and labor are spared for reading the identification information, and trouble such as deterioration and damage from to attempting to read the identification information from storage medium cartridges which do not have the identification information storers can be prevented.

Abstract: A cassette transfer mechanism for transferring a cassette recording medium to and from a cassette accommodating portion for accommodating cassette recording mediums, the cassette transfer mechanism having a unit which stores information in a memory included in the cassette and/or reads information from the same and which has a connector structured to be brought into contact with a memory terminal provided for the cassette recording medium when information is stored in the memory and/or read from the same. The above-mentioned structure enables information to be stored in the memory included in the cassette and/or read from the same without a necessity of loading the cassette recording medium into a drive unit whenever information is stored/read.

Abstract: A cartridge auto-changer includes a main unit (12) within which a vertical array of shelves (4a) and disc drives (6a) are arranged, and a carrier (2) positioned behind the shelves and disc drives and moved in a vertical direction. An extension unit (22) includes a vertical array of shelves (4b), and disc drives (6b). The extension unit is removably attached to the back of the main unit through an attachment mechanism (23). This arrangement allows for mounting of additional shelves and disc drives, as may be needed.