Browse Prior Art Database

Para Associative Storage

IP.com Disclosure Number: IPCOM000076896D
Original Publication Date: 1972-May-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Tsui, F: AUTHOR

Abstract

Associative selection is achieved by dynamically comparing data bits Di read from records on a disk track D with key bits Ki stored in key register KR. Masking register MR and AND-gate A mask out the "don't-care" bits. KR and MR are ring shift registers of variable length, which are shifted synchronously with the movement of disk track D.

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Para Associative Storage

Associative selection is achieved by dynamically comparing data bits Di read from records on a disk track D with key bits Ki stored in key register KR. Masking register MR and AND-gate A mask out the "don't-care" bits. KR and MR are ring shift registers of variable length, which are shifted synchronously with the movement of disk track D.

During associative read, the masked out bit positions in KR are used in anticipation of a match to store part of the record being read. A record found matching appears in its entirety in KR and can be outputted while the next record is scanned.

For associative write, two additional ring shift registers of variable length are used: a matching-record-marker register MRM and a duplicate-processing-inhibitor register DPI, each providing as many bit positions as there are records on track D. All bits in MRM and DPI are reset to "0"s at the start of processing a track. A "1" is stored in MRM to indicate that an associatively scanned record has been found matching. A 1 is stored in DPI to signify that a scanned record is a mismatch or that a matching record has been written into.

The MRM bit and DPI bit together are used to control the writing-over of the recording during the next disk revolution after the scan. DPI containing all 1's then signals that a track has been fully processed.

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