A disk cartridge for a disk drive has a slide door normally biased to the closed position. A recess on the door is positioned laterally offset from the horizontal center as to be oriented in either the upper or lower portion of the door depending on the orientation of the cartridge housing. The recess...http://www.google.de/patents/US4791511?utm_source=gb-gplus-sharePatent US4791511 - Disk cartridge with slide door engageable in either of two orientations
