Abstract: A plurality of rotary circular racks are vertically disposed. Each of the racks has a plurality of radial slits, for storing recording mediums, and a radially formed recess without the slits. The recesses of all racks are located at the same circumferential position. A disc player is provided to be vertically moved passing through the recess for reproducing a disc removed from one of the slits. An encoder comprising a plurality of slits are circumferentially provided on each of the racks, and a sensor is provided for detecting an angular position of each of the slits, whereby an angular position of all of the racks is determined in order to reproduce a selected disc stored in one of the racks.

Abstract: A cartridge of write and read type or a cartridge of read only type is selectively loaded to a recording and reproducing apparatus. The recording and reproducing apparatus is provided with: a magnetic head for applying a magnetic field; a head movement device for moving the magnetic head between a near position and a far position; a switching lever, which is movable between a non-regulating position to allow the magnetic head to move between the near position and the far position, and a regulating position to regulate the position of the magnetic head at the far position; and a slide plate disposed movably on a cartridge holder and having a protruded portion which is opposed to the cartridge stored in the cartridge holder. The protruded portion abuts to the loaded cartridge to move the slide plate, and the switching lever is positioned at the non-regulating position by abutting to the moved slide plate if the loaded cartridge is the write and read type.