Abstract: A recording system stores recording cycle information identifying the parameters for recording user data on a particular data sector. During a subsequent operation, the recording system employs the recording cycle information to select a different set of parameters for recording new user data at the particular data sector. One of the parameters might identify a recorded pattern in a balance pad at the data sector, and another one of the parameters might identify a scrambler seed value. By employing a different set of recording parameters for each occurrence of recording user data at the particular sector, sample timing of, for example, a read channel might be based on an average of easy and hard transitions.

Abstract: A three-phase spindle motor has three terminals each driven with pulse width modulated signals. Rotation of the motor is controlled by iteratively measuring an electrical period of the motor, determining a rotational position of the motor, and synchronizing the sinusoidal pulse width modulation of the spindle motor with the measured electrical period. The electrical period of the motor is measured by detecting zero crossings in the a back electromotive force induced at a first terminal of the motor and determining the time between successive zero crossings. The rotation position of the motor is determined based upon the last measured electrical period and a location of last detected zero crossing. The zero crossings are detected by selecting a time window during which the back electromotive force signal is sensed for zero crossings. The time window is selected as a function of the last measured electrical period and the rotational position of the motor.

Abstract: A three-phase spindle motor has three terminals each driven with pulse width modulated signals. Rotation of the motor is controlled by iteratively measuring an electrical period of the motor, determining a rotational position of the motor, and synchronizing the sinusoidal pulse width modulation of the spindle motor with the measured electrical period. The electrical period of the motor is measured by detecting zero crossings in the a back electromotive force induced at a first terminal of the motor and determining the time between successive zero crossings. The rotation position of the motor is determined based upon the last measured electrical period and a location of last detected zero crossing. The zero crossings are detected by selecting a time window during which the back electromotive force signal is sensed for zero crossings. The time window is selected as a function of the last measured electrical period and the rotational position of the motor.

Abstract: An apparatus and method for demagnetizing a write head of a disc drive. Under control of a clock oscillator, synthetic demagnetizing pulses are generated and applied to a writer-driver bridge. Also under control of the clock oscillator, a write current produced by the writer-driver bridge incorporates the demagnetizing pulses and ramps down to about zero. The train of demagnetizing pulses and the write current ramp down demagnetizes the head, reducing write head magnetic bias that may influence the proximate read head of the disc drive head.

Abstract: A carton for a foam dispensing system which includes supply containers, a dispenser and hoses for connecting each container to the dispenser. The carton includes first and second face panels which are interconnected by respective first and second side panels. Bottom panels extend from the first and second face panels to define a bottom of the carton. The cover panel extends from the first face panel to define a cover of the carton. A first flap which is defined in the cover panel, which, in an open position, is disposed at an angle to the cover panel. A handle is connected to the containers for carrying the carton and projects through the first access opening. A second flap is defined in the second face panel and the first reinforcing element. A third flap is defined in the second flap. The hoses extend from the containers, through hose paths associated with the second flap to the dispenser.

Abstract: A carton for a foam dispensing system which includes supply containers, a dispenser and hoses for connecting each container to the dispenser. The carton includes first and second face panels which are interconnected by respective first and second side panels. Bottom panels extend from the first and second face panels to define a bottom of the carton. The cover panel extends from the first face panel to define a cover of the carton. A first flap which is defined in the cover panel, which, in an open position, is disposed at an angle to the cover panel. A handle is connected to the containers for carrying the carton and projects through the first access opening. A second flap is defined in the second face panel and the first reinforcing element. A third flap is defined in the second flap. The hoses extend from the containers, through hose paths associated with the second flap to the dispenser.

Abstract: A handle assembly for holding together a pair of bulky fluid supply containers, such as liquid foam reaction product containers is provided that has a unique force exerting characteristic. The two containers are encircled by a flexible band capable of tightening, while a wire form member is provided that attaches to the supply container handles. This wire form member may serve as a handle and it has two diverging leg portions with free ends that engage the handles of the supply containers. The leg portions exert an outward force due to their divergence on the supply containers to bias them outwardly against the band.

Abstract: A multiple adhesive bead applicator has a handle member and a cross member. A network of adhesive distribution tubes is attached to the application and extends from the handle member to multiple distribution points in a preselected spacing on the cross member. Such an application is useful in a method for applying a cover member, such as an elastomeric membrane or insulation board, to a roofing substrate by first positioning the membrane adjacent a work area, then dispensing multiple beads of an adhesive onto the substrate in a preselected spacing and in a single pass and contacting the adhesive beads with the cover member.

Abstract: A multiple adhesive bead applicator has a handle member and a cross member. A network of adhesive distribution tubes is attached to the application and extends from the handle member to multiple distribution points in a preselected spacing on the cross member. Such an application is useful in a method for applying a cover member, such as an elastomeric membrane or insulation board, to a roofing substrate by first positioning the membrane adjacent a work area, then dispensing multiple beads of an adhesive onto the substrate in a preselected spacing and in a single pass and contacting the adhesive beads with the cover member.

Abstract: Method and apparatus for providing constant density recording is described. A single set of reconfigurable electronics is employed to control the write frequency for a plurality of frequency zones on a magnetic storage disk. The reconfigurable electronics include means for selectively switching a frequency response determining element within a common channel. Switching is controlled by a digital signal provided by a disk file control microprocessor, avoiding the necessity of mechanical linkages and/or changes in spindle rotation rate. The plurality of zones need not be of equal radius in width but the recording frequency within each zone is fixed throughout that zone. Zone selection is under the control of a disk file control microprocessor which produces a digital code to appropriately configure the electronics for the particular zone. Zone switching is done only when a seek across a zone boundary occurs so that no access time penalties result.