Abstract: Cartridges containing a tray retained flexible disc with the tray locked to the cartridge housing are accepted so that the tray is unlocked and withdrawn from the cartridge housing into an operating position internal to a receiver. The cartridge housing is held in a relatively fixed position so that it cannot be removed from the receiver unless the tray has been properly returned to the cartridge housing and again locked therein. The flexible disc is automatically clamped into a spindle arrangement and rotary motion applied thereto when a detector indicates that the disc is in the proper operating position. The tray is returned to the cartridge housing in essentially a reverse sequence from the loading operaton but with additional means for insuring that the disc has stopped rotation prior to return to the tray and is properly seated on the tray prior to its return to the cartridge housing.

Abstract: A flexible or "floppy" disc such as is used for data storage is retained within an enclosure that substantially protects it from contaminants or damage from handling while not in use but still permits ready access to the disc by a machine. A hub nests the disc in a bore on a tray which is received by an envelope-type of housing so that a complete enclosure is provided. The flat surfaces of the housing act to retain the disc hub within the bore while in the cartridge. A latching arrangement between the tray and the housing permits either manual or machine release of the tray. The entire housing containing the tray and the disc is readily adapted to loading within a machine by means of a hub-engaging spindle to lift the disc from the tray after it has been removed from the housing. Strategically located ridges guide the disc hub into proper tray engagement when the disc is stored in the cartridge. A plurality of slots on the tray augment air flow under the disc.

Abstract: An electronic feedback control system which compensates for errors in the position information signals output from a pair of photodetectors in a linear motion position transducer, such as used to locate a read-write head over an addressed track in a magnetic disc file system. The control circuitry sums the instantaneous values of the time varying photodetector outputs to produce a combined output signal. The peak positive value of the combined signal is determined and compared with a preselected reference value. An error signal proportional to the difference between the peak and reference values is generated and amplified to produce a correction signal. The correction signal is then applied to the variable energization input of the light source which illuminates the photodetector pair. The correction signal reduces the error signal toward zero by causing the light source to compensate for error in the photodetector output signal.