04935835 is referenced by 36 patents and cites 20 patents.

A magnetic medium including a physical reference feature for conveying positional information to a magnetic read/write head. The reference feature is made by indelibly marking a pattern on a surface of the medium such as by inscribing the metal oxide coating on the medium surface or by chemical etching or photolithography of the surface. Magnetic data is written on the surface of the medium and when data written on the reference feature is read, a modulated read back signal is observed which indicates the position of the reference feature. The position of the reference feature is used to direct the read/write head to track zero or to some other position on the medium surface. By using a second magnetic read/write head to write data on a second surface of the medium in response to the modulated readback signal, an electronic reference track can be written on the second surface for providing positional information to the second magnetic read/write head.

Title
Magnetic media containing reference feature and methods for referencing magnetic head position to the reference feature
Application Number
7/269779
Publication Number
4935835
Application Date
November 10, 1988
Publication Date
June 19, 1990
Inventor
Alton B Otis Jr
San Francisco
CA, US
Stephen P Williams
San Jose
CA, US
Roger O Williams
Fremont
CA, US
Jimmy D Godwin
San Jose
CA, US
Agent
Thomas E Schatzel
Assignee
Insite Peripherals
CA, US
IPC
G11B 5/56
G11B 5/82
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