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Adaptive Positioning of Streaming Tape Drive

IP.com Disclosure Number: IPCOM000041961D
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03

Publishing Venue

IBM

Related People

Authors:
Lockett, DE [+details]

Abstract

In streaming operation, a tape drive depends upon continuous tape motion at its regular velocity for high efficiency performance. In a typical operation, the host system commands the drive to read a given record, and after the record has been read, the host supplies another command to read the next following record. If the host system does not supply the read command within a following interval defined as a reinstruct window, then the drive must stop and reposition itself for access to the next data block. This repositioning is normally called back-hitching and requires a significant time which degrades the effective overall performance of the drive. An improved technique is described which allows a drive of the streaming type to operate in either a continuous "streaming" mode or in a start/stop mode.