Fault location method in mass-storage system

A fault location method for a mass storage system comprising a recording medium divided into tracks and a main unit comprising a respective read/write head corresponding to each of said tracks, said method comprising

• storing at a predetermined location in each of said tracks the home address of that respective track, said home address comprising the respective track address,
• providing a diagnostic test area at a respective location in each of said tracks,
• storing in at least one predetermined location of at least one of said tracks the addresses of all said diagnostic areas of all said tracks,
• when a fault is detected during a read/write operation in a particular track, reading the home address area of that particular track and storing the track address of that particular track in said main unit,
• reading the addresses of all said diagnostic areas of all of said tracks from said at least one predetermined location of said at least one track,
• selecting the diagnostic test area within said particular track in use when said fault was detected, and
• applying diagnostic read/write operations to said selected diagnostic test area.

A diagnostic method in a mass storage system comprising a recording medium divided into tracks and a main unit comprising a respective read/write head for each of said tracks and a demodulator circuit for selecting one of said tracks for a selected read/write operation, said method having the object of distinguishing between a fault in said main unit from a fault in said recording medium, said method comprising

• reading the home address of the track that is the subject of a read/write operation when a fault is detected, said home address reading occurring before another track of said recording medium is selected for another read/write operation after said fault detection,
• verifying said home address that is read upon said fault detection to verify the read operation of the respective head and read circuitry of said main unit,
• reading from a predetermined area of a predetermined track the locations of plural diagnostic areas in said tracks,
• searching said addresses of said diagnostic areas for selecting one of said diagnostic areas that is located in said track being subjected to said read/write operation when said fault was detected, and
• writing predetermined diagnostic data into said selected diagnostic area for subsequent read out and verification of said writing of said predetermined data.

A mass storage system comprising means for determining the location of a fault, said system comprising

• plural tracks in a magnetic recording medium, each said track comprising a home address area for storing the home address of the respective track and a diagnostic area,
• an area in one of said tracks for storing the locations of all said diagnostic areas,
• a main unit comprising a read/write head for each of said tracks, a multiplexer for selecting one of said heads according to instructions from said main unit, a head carriage motor for moving all of said heads as a single integrated structure, a servo control circuit for controlling said head carriage motor, a modem for connecting said selected head for input/output of the corresponding track with said main unit, read and write registers for storing data for selective read/write operations within said tracks,
• fault detection means connected to one of said read registers for detecting a fault in one of said read operations,
• read home address means for reading and storing the home address of a track subject to a read operation when a fault is detected,
• diagnostic area search means for searching for said area of said track where said locations of said diagnostic areas are stored, and
• diagnostic areas detection means for locating said diagnostic area in the one of said tracks subject to said read operation when said fault is detected.