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Semiconductor Volume Table of Contents for Data Cartridges

IP.com Disclosure Number: IPCOM000110820D
Original Publication Date: 1994-Jan-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Battelle, D: AUTHOR [+2]

Abstract

Currently, computer data cartridges such as tape, optical, etc., have their Volume Table of Contents (VTOC), if any, recorded internally on their storage media. Tape cartridges, in particular, usually do not contain a VTOC. The entire media must be scanned for datasets in order to build a VTOC for the cartridge.

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Semiconductor Volume Table of Contents for Data Cartridges

      Currently, computer data cartridges such as tape, optical,
etc., have their Volume Table of Contents (VTOC), if any, recorded
internally on their storage media.  Tape cartridges, in particular,
usually do not contain a VTOC.  The entire media must be scanned for
datasets in order to build a VTOC for the cartridge.

      An automated cartridge library system having a VTOC that is
readable without first having to mount the cartridge in a drive has
certain advantages.  First, it allows the library to inventory
datasets in addition to or instead of volumes, allowing the library
to implement a 'Locate Dataset' command.  A second advantage is that
the library could prefetch positioning information for a particular
dataset at the same time it is physically moving a cartridge during a
mount operation, allowing faster access to the dataset once the mount
is complete.

      This article describes one way to implement a data cartridge
VTOC that is read/writeable without requiring that the cartridge be
mounted in a drive.  The semiconductor VTOC consists of a
non-volatile memory array, a power source and a communications
channel in a form suitable for attachment to a data cartridge.  The
power source would be either a battery or derived inductively from
the field generated by the library's magnetic cartridge picker.  The
communications channel would be a serial interface.

      Placing the host s...