Browse Prior Art Database

Contamination Notification and Recovery for Optical Disk Drive

IP.com Disclosure Number: IPCOM000113294D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Ikegami, T: AUTHOR [+2]

Abstract

Disclosed is a method of diagnostics and recovery for contaminated MO-disk drive system. The host system detects contamination of a drive or a media by specific SCSI commands, and then the system informs a user to clean up the drive or media. After the drive and media are cleaned, the system sends another specific command to the drive to release spare sectors used as replacement of defective sectors which get usable again after cleaning.

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Contamination Notification and Recovery for

Optical Disk Drive

      Disclosed is a method of diagnostics and recovery for
contaminated MO-disk drive system.  The host system detects
contamination of a drive or a media by specific SCSI commands, and
then the system informs a user to clean up the drive or media.  After
the drive and media are cleaned, the system sends another specific
command to the drive to release spare sectors used as replacement of
defective sectors which get usable again after cleaning.

      To realize this method , MO-drive needs to have following 3
fanctions via SCSI commands.

    a.  The drive detects contamination of optical parts of the drive
       by 'ADC value' which represents Read Signal Ampletude
       converted from analog data to digital value.  The drive
       returns a flag of contamination, 'Good' or 'Warning', and the
       ADC value to the host.

    b.  The drive detects contamination of a MO-media by information
       table of defect sectors, called PDL/SDL, on a media.  The
       drive returns a flag of contamination, 'Good' or 'Warning',
       and the number of PDL/SDL entries to the host.

    c.  The drive releases spare sectors for revived defective
       sectors of the media by refreshing the SDL.

      The Figure shows flow of the example of utility programms of
the contamination diagnostics and recovery for the MO-disk drive
system.

1.  The host system sen...