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Forced Gap Reduction Tests

IP.com Disclosure Number: IPCOM000090200D
Original Publication Date: 1969-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Marcotte, DO: AUTHOR

Abstract

Operational history and maintenance requirements for a magnetic tape unit can be obtained by periodically reading records containing sequentially decreasing gaps. By forcing the write circuitry of a tape drive unit for all tracks to fail to record data for selected intervals, records can be written which are separated by a nominal interblock gap and a sequence of gaps of decreasing length. These gaps are created by forcing the write circuitry for all tracks of the magnetic tape drive to fail to record data transitions for a preselected period of time. The records are then read in the forward and backward directions with these functions being performed a predetermined number of times for each record between the simulated gaps.

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Forced Gap Reduction Tests

Operational history and maintenance requirements for a magnetic tape unit can be obtained by periodically reading records containing sequentially decreasing gaps. By forcing the write circuitry of a tape drive unit for all tracks to fail to record data for selected intervals, records can be written which are separated by a nominal interblock gap and a sequence of gaps of decreasing length.

These gaps are created by forcing the write circuitry for all tracks of the magnetic tape drive to fail to record data transitions for a preselected period of time. The records are then read in the forward and backward directions with these functions being performed a predetermined number of times for each record between the simulated gaps. After the last record is read, a printed summary is generated indicating the number of successful and unsuccessful read attempts for both forward and backward for each simulated gap size between the record. At some gap size, an indication of all failures results since the read-write heads begin entering into the next data block before they cease moving. The recorded information aids in determining whether the gaps being used for that machine need adjustment or how much deviation from nominal the tape unit can withstand before a permanent read error occurs. By periodically performing these gap tests, a history of a particular machine can be maintained and indications of maintenance requirements are realized.

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