Browse Prior Art Database

Tape Drive Interlayer Slip Detection and Recovery

IP.com Disclosure Number: IPCOM000044576D
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 2 page(s) / 62K

Publishing Venue

IBM

Related People

Koski, JA: AUTHOR [+3]

Abstract

When tape reels are subjected to environmental changes, a phenomenon known as interlayer slip can occur when the tape is loaded into a tape drive. In a reel-to-reel tape drive it is essential that any interlayer slip in the reel be removed. A preferred method is to detect the existence of the potential for slip and remove it. U.S. Patent 4,389,600 describes one method of detecting interlayer slip. In the patent, the end of the tape is held stationary while the tape reel is driven in the rewind direction. In the present proposal, the tape is loaded into the tape drive, stopped, and then accelerated to the normal forward velocity of the tape at 1.5 the normal acceleration rate. A tachometer mounted on the supply reel drive detects any velocity variations of the tape. This cycle is repeated a fixed number of times.

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Tape Drive Interlayer Slip Detection and Recovery

When tape reels are subjected to environmental changes, a phenomenon known as interlayer slip can occur when the tape is loaded into a tape drive. In a reel-to-reel tape drive it is essential that any interlayer slip in the reel be removed. A preferred method is to detect the existence of the potential for slip and remove it. U.S. Patent 4,389,600 describes one method of detecting interlayer slip. In the patent, the end of the tape is held stationary while the tape reel is driven in the rewind direction. In the present proposal, the tape is loaded into the tape drive, stopped, and then accelerated to the normal forward velocity of the tape at 1.5 the normal acceleration rate. A tachometer mounted on the supply reel drive detects any velocity variations of the tape. This cycle is repeated a fixed number of times. One procedure for performing the interlayer slip test is shown in the flow diagram. Tape is loaded and fed into the tape drive to position the beginning-of-record (BOT) in position to be read by the tape head. The tape movement is stopped for a 20-millisecond delay period. This enables the tape to be placed in a rest state. A Counter A maintains a count of the number of times the tape has been cycled for interlayer slip. The count in Counter A is sensed after each 20-millisecond delay period, and when a count of 10 is detected, indicating an adequate number of test cycles, a set ready status signal is prov...