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Saving Random Access Memory in the Event of a Power Failure

IP.com Disclosure Number: IPCOM000082195D
Original Publication Date: 1974-Oct-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Hippert, RO: AUTHOR [+2]

Abstract

Many systems, particularly data-collection systems, utilize volatile random-access memory as well as disk memory. Occasionally, power outages will cause loss of the volatile random-access memory.

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Saving Random Access Memory in the Event of a Power Failure

Many systems, particularly data-collection systems, utilize volatile random- access memory as well as disk memory. Occasionally, power outages will cause loss of the volatile random-access memory.

Described is a technique suitable for preventing such losses during power outages. When the power outage is detected, that is, during the initial states of a power outage, the data stored in the volatile random-access memory is transferred from that memory to the disk storage device. Thus, at the termination of the power outage, the data transferred in the early stages of the power outage is restored into the volatile random-access memory.

Three areas of the system design are influenced. The power supply must be designed with a sensor which monitors the input voltage levels, to detect when the input voltage drops to 80% of nominal. Once this condition is detected, it is communicated to the processor which causes the highest level interrupt to be generated, to immediately start transferring the data stored in the random-access memory to the disk.

The energy stored in the power supply is utilized for effecting the readout of the information from the random-access volatile memory. The energy stored in the rotating disk and in the power supplies, will permit sufficient time to transfer vital data from the volatile random-access memory to the disk storage. On power recovery, the system may be brought back up automat...