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Browse Prior Art Database

Verifying Storage Formats

IP.com Disclosure Number: IPCOM000049975D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Christian, JH: AUTHOR [+3]

Abstract

In a buffered DASD (direct-access storage device) system, the logical design of the buffer portion may dictate certain restrictions on the format of data stored on the DASD. Since various DASDs have diverse formats, compatibility is to be verified. Control characters on the DASD are read out and compared with a range of permissible control characters for the buffer portion. Upon a favorable compare, data processing operations ensue. Upon a miscompare, a format error is indicated and the attached host is notified for error recovery procedures.

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Verifying Storage Formats

In a buffered DASD (direct-access storage device) system, the logical design of the buffer portion may dictate certain restrictions on the format of data stored on the DASD. Since various DASDs have diverse formats, compatibility is to be verified. Control characters on the DASD are read out and compared with a range of permissible control characters for the buffer portion. Upon a favorable compare, data processing operations ensue. Upon a miscompare, a format error is indicated and the attached host is notified for error recovery procedures.

One or more disk storage apparatus DASDs are connected to a buffered control unit. The buffered control unit is controlled by a program processor (not shown), which operates the buffer via the table lookup directory. Upon each read, or upon a first read from each track of DASD, the control character indicating the length of the data field is stored in the length field register. The permissible buffer record lengths, also stored in a register, are compared by the illustrated compare circuit (program). Upon a favorable compare with the length of record in the buffer and length of record on DASD, a gate G is enabled to permit data transfer between the buffer and the DASD using the directory to access the buffer. Otherwise, an error is indicated, which sets a format error (FE), flip-flop as well as supplying an error indication to the host.

Using the above-described verification techniques, a plurality...