Abstract: A drive and tape cartridge provide motor control for the tape tension in a belt-driven tape cartridge. Two different rollers drive the belt, and are controlled by two separate motors. This allows reduction in the friction required in the system and allows optimal sizing of the motors.

Abstract: A direct file access system for a magnetic tape where all data files begin at a designated location on the tape. The direct file access system may be used with a reduced rewind data configuration to decrease data access time. The reduced rewind data configuration divides data files into generally equal portions so that data files begin and end at the designated location on the tape, eliminating rewind sequences. A method and system for reducing the number of tape retensioning passes is included to further decrease access time.

Abstract: A scanning and/or tracking mechanism for use in airborne obstacle avoidance ptical radars operating in the infrared region. The radar beam is scanned by passing it through a pair of in-line rotating optical wedges which rotate around the boresight axis and which are transparent to the infrared radiation. The wedges are separately driven by servo systems including hollow shaft torque motors with the wedges mounted in the hollow shafts thereof. A high resolution and low backlash shaft position encoder is utilized comprising encoding discs directly driven by the optical wedges and including a novel decoding system.

Abstract: A data cartridge recorder is disclosed in which a preformatted tape is employed to enable automatic detection of the beginning of the tape and the end of the tape as well as of the location of preidentifiable record locations positioned along a plurality of parallel tracks.