Dynamic information storage or retrieval – Information location or remote operator actuated control – Selective addressing of storage medium
Reexamination Certificate
1999-04-29
2001-12-11
Dinh, Tan (Department: 2651)
Dynamic information storage or retrieval
Information location or remote operator actuated control
Selective addressing of storage medium
C369S047150
Reexamination Certificate
active
06330210
ABSTRACT:
FIELD OF INVENTION
This invention relates generally to data storage media and more specifically to data structures used for various identification and control attributes for a rewriteable medium.
BACKGROUND OF THE INVENTION
A data storage medium typically includes an area for storage of various administration and control information, such as an identification of the medium, perhaps information regarding how the medium is partitioned into various separate sections, a directory or table of file names and dates, and perhaps information regarding access control. Administration and control information may reside in a particular physical location on a medium separate from a general data storage area. For example, compact discs (CD) used for data storage have a single spiral track, with an area near the start of the track called a lead-in area, and an area near the end of the track called a lead-out area. The information in the lead-in area and the lead-out area contains administration and control information used only by drives and operating systems, and is separate from the area used for data storage.
Sometimes, a data storage medium has a format that is specific to a proprietary drive mechanism, or specific to one computer operating system. Alternatively, some formats are defined by standards, so that a medium can be exchanged among drives from multiple manufacturers and may be used by multiple computer operating systems. Standards are useful in eliminating unnecessary variation, but standards may also inhibit change, even when change is needed. For example, CD's were originally developed for read-only digital audio. As the CD technology was extended to general data, and write-once media, and rewriteable media, accommodation of new features with backwards compatibility was always an issue. There is a need for a standard way of recording administration and control information, for interchangeable rewriteable media, that can accommodate unforseen needs for changes in the future.
SUMMARY OF THE INVENTION
One goal of the invention is to provide a standard, but very general and flexible, data structure for recording administration and control information for a rewriteable storage medium, particularly when drives and media may be provided by many different manufacturers. Accordingly, a data structure, called a Disk Control Block (DCB), is defined. One medium may contain multiple different DCB's, each addressing a different function. Several examples of DCB's are provided. One example is called a General Media (GM) DCB. The GM DCB contains information such as a counter that counts how many times the medium has been loaded, control information for formatting of the medium by the drive, and power calibration information. Another example DCB is called an Access Control (AC) DCB. An AC DCB may be used to partition a disk into multiple sections, and for each section the DCB defines an access attribute such as write-once, or read only with password, or other similar access control. Another example is a DCB for updating firmware.
Another goal of the invention is to provide a data structure such that if a drive encounters an unrecognized DCB, the drive can still decode an essential set of standard control parameters in the unrecognized DCB, so that the drive behavior is not inconsistent with the requirements of the unrecognized DCB. Each DCB includes a control block identifier that specifies the function of the DCB. Each DCB also includes an area called Unknown Content Descriptor Actions (UCDA), which specifies certain actions a drive must take if the drive does not recognize the identifier for the DCB.
An additional goal of the invention is to ensure the reliability of DCB's even if the disk is defective, or even if power is interrupted during writing of a DCB. In an example embodiment, redundant DCB's are provided, and each DCB has a sequence number. Identical identifiers with identical sequence numbers indicate identical (deliberately redundant) DCB's. If one copy is invalid, the invalid copy is replaced by the valid copy. Identical identifiers with different sequence numbers indicate that writing of a DCB was interrupted, and the DCB having the oldest (lowest) sequence number, for the particular identifier, is used.
REFERENCES:
patent: 4827462 (1989-05-01), Flannagan et al.
patent: 5173886 (1992-12-01), Satoh et al.
patent: 5214627 (1993-05-01), Nakashima et al.
patent: 5233576 (1993-08-01), Curtis et al.
patent: 5247494 (1993-09-01), Ohno et al.
patent: 5265230 (1993-11-01), Saldanha et al.
patent: 5337197 (1994-08-01), Brown et al.
patent: 5537636 (1996-07-01), Uchida et al.
patent: 5592452 (1997-01-01), Yoshimoto et al.
patent: 5644444 (1997-07-01), Braithwaite et al.
patent: 5684785 (1997-11-01), Itami et al.
Larner Joel B
Weirauch Charles R
Dinh Tan
Hewlett--Packard Company
Winfield Augustus W.
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