Irwin Magnetic Systems, Inc.

Other

Conner Peripherals, Inc.

Marlin K Klumpp

Housan Dakroub

John M Chambors

Samuel N Irwin

Francis Lum

Lawrence J Tucker

Michael L Bolt

Joseph H Mueller

Richard A Farkas

Robert G Voss

Nick A Skogler

Bruce V Janiszewski

A multi-track servo-recording format includes servo zones defined longitudinally by stripes extending across the width of a storage member. Track centering signals are provided within each servo zone for locating the center of each data track on the storage member. Track-identifying indicia are provided at the beginning and end of the storage member and in each written track.

Multi-track embedded servo recording format and method

The specification discloses means for correcting timing variations present in a data stream emanating from a data storage device such as a magnetic tape drive or the like before the data stream is applied to the data separator or other such input device of a computer. This is accomplished by remodulating the time-varying bits in the data stream in a manner which reduces or eliminates the undesired timing variations. Basically, the system utilizes frequency-modulation techniques to in effect remodulate the raw data stream. The application discloses, as one preferred embodiment, a pulse-width modulator which receives the error signal output of a phase-locked loop network, the input of the pulse-width modulator being coupled to the incoming raw data stream. The primary output of the phase-locked loop circuit is coupled to the input of the pulse-width modulator, and the output of the pulse-width modulator is coupled to the input of a pulse generator so as to produce output pulses of substantially uniform width which occur in synchronism with output pulses of the pulse-width modulator and thus constitute in effect a remodulated version of the raw data stream, in which the undesired timing variations have been removed or reduced by an acceptable level.

Method and apparatus for removing data stream variations

A recording member for digital data, particularly a recording tape, has a plurality of generally parallel, closely-spaced recording tracks which each contain pre-recorded track-identifying and transducer-positioning servo information, as well as defined data-recording areas. The pre-recorded track-identifying information preferably comprises a digitally-encoded individual track address, and the servo information comprises separate bursts used in centering the transducer upon a particular track. Preferably, each such track has a dedicated area at its beginning, end, or both, which contain continuous repetitions of such positioning information, there being no data areas in such dedicated portions. Digital encoding of track addresses utilizes binary-type code format, accomplished by defining a binary 'zero' as a recorded burst present at a first number of sampling points, and defining a binary 'one' as a burst present at a second number of sampling points of a second duration. The pre-recorded positioning information includes certain non-recorded 'gaps' which serve as initializing signals, and the preferred system for utilizing the pre-recorded, servo-controlled record member utilizes peak-detection and minimum-threshold techniques to accurately distinguish unrecorded gaps from noise, or the like, on the one hand, and to distinguish coded signal bursts from other possible recorded signals, or noise, on the other hand. The preferred system is entirely self-clocking, i.e., the record member does not carry a recorded clock track, and thus does not require the additional transducer required where recorded clock tracks are used; at the same time, the area on the record member otherwise occupied by the clock track is available for data-recording usage.

Data record with pre-recorded transducer positioning signals, and system

A remotely controlled powered aircraft equipped with engine, propeller and landing gear, radio-controlled from the ground and capable of towing a manned hang glider to an appropriate altitude. On reaching altitude, the pilot of the hang glider releases the tow, and the pilotless towing aircraft is returned to the launching site under radio control from the ground. During towing of the hang glider, two-way communication is maintained between the hang glider pilot and the towing aircraft remote pilot.

Remote control hang glider towing aircraft

Growing community of inventors

Tecumseh, MI, United States of America

Marlin K Klumpp