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Disk Drive Power-Down/Reset Write Error Protecton

IP.com Disclosure Number: IPCOM000037500D
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Corchero, CA: AUTHOR

Abstract

Disk drives can damage disks mounted therein if system power is removed or a reset occurs while the disk is being updated. Some disk drives maintain limited protection by blocking resets from error conditions until disk updating is complete. However, the blocking mechanism is complex and offers no protection from power removal. Some disk drives maintain protection by a light which signals the operator when a disk is being accessed. These drives are disadvantageous in that operator attention is required, and because the light may not be visible to the operator when the drives are installed in storage controls made by a manufacturer other than that for the drive. The problem thus presented is how to simply and automatically provide protection against disk drive power-down and reset write errors.

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Disk Drive Power-Down/Reset Write Error Protecton

Disk drives can damage disks mounted therein if system power is removed or a reset occurs while the disk is being updated. Some disk drives maintain limited protection by blocking resets from error conditions until disk updating is complete. However, the blocking mechanism is complex and offers no protection from power removal. Some disk drives maintain protection by a light which signals the operator when a disk is being accessed. These drives are disadvantageous in that operator attention is required, and because the light may not be visible to the operator when the drives are installed in storage controls made by a manufacturer other than that for the drive. The problem thus presented is how to simply and automatically provide protection against disk drive power-down and reset write errors.

The aforementioned problem is solved by providing a disk drive with the means to complete an update in progress and thereafter block any further updating once a system power-down or reset is detected. The blocking is continued until updating can resume without causing damage to the disk. The means for accomplishing the blocking is shown in Figure 1. The power supply must allow enough time between the powerdown sequence indication and the actual start of the decay of the power for a drive update to be completed and for the disk controller to properly sequence down the control signals to the disk drive. The AND gate, inverter,...