Abstract: The signal read-back from a magnetic disk is processed in dependance upon the track diameter in order to cut higher frequencies for outer tracks and to boost high frequencies for inner tracks for, respectively, correcting flat signal portions and eliminating or reducing peak displacement. The circuit develops a signal-amplitude-modifying factor in form of a cosine function of the frequencies of the read-back signal as applied. Two thus modified read-back signals are developed, varying oppositely in strength in dependance upon the track diameter. These two signals are combined to obtain the selective cutting or boosting as required.

Abstract: The tunnel-erase-type guard band "writing" along the tracks of a disk in a disk file is controlled by the same microcomputer which controls transducer repositioning in the seek mode. The micro-computer meters different delays for onset and cessation of erasing in relation to a signal (write gate) accompanying the data to be recorded; and these delays are longer for tracks having smaller diameters. The leading and trailing edges of the write gate signal trigger interrupts for the microcomputer, the interrupt channel is released only after the particular delay has been metered.

Abstract: A voice coil type linear motor controls the movement and positioning of a transducer which cooperates with a spinning disk. The motor is feedback controlled for separate speed (seek) and positioning modes in which respectively the transducer is moved across the disk towards a different track and is held centered above that track. In order to offset the effect of a tilted axis of carriage movement, the control condition in the positioning mode representing a correct transducer position in which it is held by the motor, is continuously sampled and held during a period when the transducer is moved to another track to be applied as correction for the control moving the transducer towards another track. This correction signal is also used in the initial phases of holding the transducer above the newly selected track, until sampling and positioning control proper takes over.

Abstract: Two magnetic heads are mounted respectively in front of two springs, and face each other across a gap in a frame into which a recording disk can be exerted. The springs are respectively flexed back by means of two spring biased pivot levers, so that the heads do not engage the disk. These levers have tongues in their front, which hold the springs down. A cone-ball actuator pivots the lever towards each other permitting, in turn, the springs to flex towards each other so that the heads engage the disk.

Abstract: A three part cone member assembly is provided for positioning a flexible disk on a drive hub. The three parts are, a disk with annularly arranged apertures, a plastic trunketed cone established by oblique arms and feet which stick in the apertures thereby determining the cones geometry; the third part is a metallic member with resilient arms, positioned in the plastic cone whereby each metal spring arm urges a plastic arm against the outer surface of the respective aperture.

Abstract: The disc file system being improved includes a motor driven transducer carriage for positioning the transducer in selected cylinder positions. A command unit issues step pulses and the carriage provides detent pulses respectively representing the number of tracks (cylinders) to be and being crossed when the carriage is caused to move and moves from one cylinder position to another one. These pulses are processed so that overlap is avoided in that following the trailing edge of each step or detent pulse, a process pulse, is produced either with or without delay depending on the need to avoid conflict. The process pulses to be produced are up an down counted for tracking actual carriage movement, and the total count is zero when the carriage has arrived at the desired position.

Abstract: A flexible disk is automatically coupled to a drive spindle following insertion in the drive, but decoupled and ejected on command. The positioning and ejection control runs through a three-phase cycle which halts at the end of the positioning phase and is terminated at the end of the ejection phase while disk de-coupling and ejection phases follow directly. The ejection device has an override if an obstacle holds the disk in the drive. The three-phase cycle is cam-operated, using a motor drive cam assembly whose shaft extends in the direction of disk insertion and ejection and parallel to the hinge axis of a cam-operated disk positioning hub carrier. A cam pin on the shaft actuates the disk ejection and additional cams control stop switches for the motor.