Abstract: Positioning apparatus for moving read-write transducers in data record systems achieves improved stability in the motion and positioning of such transducers with reduced complexity of structure compared with known apparatus of the prior art. A particular structure, including a female dovetail guide surface and a plurality of cooperating sloped guide wheels, one of which is spring-loaded for force balancing, causes a plurality of reference guide wheels to maintain firm and stable contact with a smooth and flat reference surface and assures the desired stable and accurate movement of the carriage.

Abstract: Apparatus for receiving and driving magnetic disc cartridges as peripheral computer memory units. Particular mechanisms are included which render the apparatus more effective and more compact than previously known corresponding devices of a comparable nature. These mechanisms cooperate to provide means for permitting the apparatus to be withdrawn partially from its mounting rack and for moving an interfering panel member out of the way to permit loading and unloading of the disc cartridge from the top of the apparatus. The mechanisms include releasable latching means and a solenoid controlled lock for preventing release of the latching means except under predetermined positions, plus means for pivoting a lid member to avoid interference with adjacent equipment.