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Browse Prior Art Database

Redundant Verification for Compact Disk-Recordable Libraries

IP.com Disclosure Number: IPCOM000117329D
Original Publication Date: 1996-Feb-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Solan, M: AUTHOR [+2]

Abstract

CD-R(ecordable) devices can have permanent read errors. Disclosed is a redundant verification for CD-R and CD-E(rasable) writer devices in libraries.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Redundant Verification for Compact Disk-Recordable Libraries

      CD-R(ecordable) devices can have permanent read errors.
Disclosed is a redundant verification for CD-R and CD-E(rasable)
writer devices in libraries.

      These libraries would have CD-ROM readers to read the disks
written by the CD-R and CD-E devices, rather than using these writers
as readers.  The reason for this is that CD-ROM readers are very
inexpensive and durable, so that the order-of-magnitude more
expensive CD-R or CD-E devices are saved solely for writing.

      The redundant verification would consist of reading the freshly
written disk in one of the CD-ROM readers before purging the data
from (a) a RAM buffer or (b) a DASD buffer.  This way, the user will
know that the data was readable in a device other than the one which
wrote the data.

      Thus, envision a library containing CD-R and/or CD-E devices
for writing data to CD-recordable disks.  For random retrievals, the
data would be read from CD-ROM readers.  After verifying the written
data in the writing device, disks would be placed into one of the
CD-ROM readers for a second (redundant) verification.  After this
verification took place, the data held at the host or in the library
in a fast-write buffer could be purged.  The ID of the recording
device would be written on the media or logged into the library
itself or the subsystem, so that poorly recorded disks could be used
to reveal defective writers.  The same...