Insite Peripherals

Mark E Strysko

Stephen Paul Williams

Roger O Williams

Andrew M Rose

Jimmy D Godwin

Alton B Otis, Jr

James Chiao

A dual magnetic head having a first magnetic core for reading and writing very high track density floppy disks and a second magnetic core for reading and writing conventional track density floppy disks. Neither the first nor the second magnetic cores require the trim erase elements associated with prior art magnetic cores for use with floppy disks. When writing on conventional track density floppy disks, separation between data tracks is achieved by erasing a circular region on a first rotation of the floppy disk, erasing a second region, separated from the first region by a small gap, on a second rotation of the floppy disk, and writing data during a third rotation of the floppy disk centered about the small gap. With very high density floppy disks, data is written directly between optical servo tracks on the floppy disk without use of the two erase steps.

Dual magnetic head and method for writing on very high track density and

A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of servo grooves on at least one of said sides of said media that have stitched patterns that will alternate on-and-off at twenty kilohertz in the presence of a constant, unmodulated light source. The diskette is magnetically formatted with reference and data tracks recorded in such a way that extremely accurate position determinations can be made by looking at the analog amplitude of the detected tracks and comparing them at different head positions. The innermost tracks contain redundant copies of a disk mapping table that comprises data for a media type code, a sector size code, a sector interleave code, a total track count, a reassignment area starting address, a data area starting address, a total sector count, an update count, and a reassignment table having at least room for 250 entries of three bytes each.

Very high-density diskette format method and computer-implemented process

Very high-density diskette format method and computer implemented process

Growing community of inventors

San Jose, CA, United States of America

Mark E Strysko