Abstract: A recorder slidably receives the opposite edges of a magnetic tape cartridge within grooved guides and locks the cartridge in an operative position using an opposite pair of movable catches which engage notches in the opposite edges of the cartridge. Cartridge ejection is effected by energizing a solenoid which pulls the opposite catches out of the cartridge edge notches along enough for a pair of spring-loaded elements to push the cartridge forward out of the operative position. A wheel located within the cartridge and coupled to drive a length of magnetic tape therein is engaged with and driven by a drive wheel when the cartridge is in the operative position. The drive wheel is mounted on a drive shaft having an end thereof opposite the drive wheel rotatably supported by a bearing and an opposite portion thereof adjacent the drive wheel supported by another bearing which is resiliently mounted by a spring within an aperture at the top of the housing for the recorder.

Abstract: An angular position transducer includes a core of magnetic material of circular shape and having a central hub extending from a central portion of and opposite outer rims extending from the outer periphery of a disk-shaped web. An armature which is of like size and shape to one half of the core so as to be semi-circular in configuration is mounted so as to undergo rotation relative to the core, the single outer rim of the armature being disposed adjacent one or the other or both of the outer rims of the core. A primary winding wrapped around the central hub of the core produces magnetic flux which flows into the armature, then through the single outer rim of the armature and adjacent portions of the outer rims of the core to a pair of secondary windings wound around the web of the core on opposite sides of the hub.

Abstract: A read amplifier generates pulses in response to the transitions of a phase encoded signal and selectively gates the pulses to an output and to a retriggerable one shot multivibrator under the control of inhibit pulses produced by the multivibrator. During a preamble of the data signal in which a known sequence of zeros is produced, a decade counter prevents generation of pulses in response to the polarity return transitions between the zeros and prevents the inhibit pulses from being applied to gate the pulses produced by the data signal until a predetermined number of zero pulses has been counted. During the preamble the inhibit pulses at the output of the multivibrator are averaged and compared with a reference so as to adjust the duty cycle of the multivibrator to produce inhibit pulses which are 70 percent of the duration of the bit intervals of the data signal.

Abstract: A dual density read circuit for a digital magnetic tape transport selectively responds to information recorded on magnetic tape in either an 800 bpi NRZI format or a 1,600 bpi phase encoded format. The read circuit includes a differentiating circuit coupled to differentiate and square the read head signal, a latch circuit coupled to latch an NRZI output data signal only when the differentiated read head signal has a change of polarity after being at a given polarity for a predetermined minimum period of time, and first and second gating circuits coupled to selectively pass the NRZI output data signal and the differentiated read head signal when enabled by NRZI and phase encoded read signals respectively. The read circuit advantageously uses common circuit components while providing excellent noise immunity for either the NRZI or phase encoded data formats.