Browse Prior Art Database

Data Retention System

IP.com Disclosure Number: IPCOM000083411D
Original Publication Date: 1975-May-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Capowski, RS: AUTHOR [+3]

Abstract

Data contained in a volatile main storage of a computer system is protected against loss in the event of an input power line disturbance (PLD) or outage. The data retention or protection system requires a limited amount of buffered power.

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Data Retention System

Data contained in a volatile main storage of a computer system is protected against loss in the event of an input power line disturbance (PLD) or outage. The data retention or protection system requires a limited amount of buffered power.

More specifically, the computer system, or at least critical portions of it is supplied automatically with continuous power 1 from a buffered power supply for some limited time during a PLD or outage.

A sensor 3 connected at 2 to the utility power is provided to detect such power faults. The PLD/outage is detected by the sensor 3 and the processor 5 is alerted via a warning signal 4.

The processor 5 interrupts the normal processing and starts executing a program, which can cause the entire contents of the volatile main storage 6 to be transferred to a nonvolatile medium 8, i.e., disk storage device.

In the processor, a machine check interrupt occurs and the machine check interrupt code (MCIC) is stored with the warning bit on. The software machine check handler is invoked and examines the warning bit. If on, it begins a software time-out routine of a specified duration. The warning bit is examined several times within this routine.

If found on continually, at the end of the specified dur~tion, software allows a user exit. If the exit is not taken, software initiates a dump of the entire contents of storage 6 onto the specified nonvolatile medium 8. If during the software time out the warning bit is examined...