International Business Machines Corporation

William Brooks Ott

David J Bradley

Gary Edward Webb

Beeman Noel Fallwell, Jr

Matt A Kaltenbach

A method and mechanism for booting an operating system in a Redundant Arrays of Independent Disks (RAID) is disclosed. The method includes: searching for a copy of a RAID driver on at least one boot partition of a disk in the disk array, wherein copies of the RAID driver are stored in boot partitions of at least two of the disks in the disk array; and loading the RAID driver, if the RAID driver is found. In the preferred embodiment, the boot partitions of the disks are searched until a working copy of the RAID driver is found. The RAID driver is loaded and the RAID implemented. The operating system may then be booted. In this manner, the need for a Flash memory device for storing the RAID driver is eliminated. The method and mechanism can be implemented in existing systems not designed to support software RAID.

Mechanism for eliminating need for flash memory in software RAID

A resistive strain gauge bridge circuit, including a pulse code modulation counter operative under an algorithm designed for calibration with a voltage signal for effectively canceling out voltage and voltage fluctuation influences to maintain centering of the operating point of the strain gauges without the excessive costs attributable to devices such as electronic potentiometers which notably have been utilized to generally achieve satisfactory performance of strain gauges included in mobile personal computer systems.

Resistive strain gauge control circuit

An interrupt interface circuit for interrupt level sharing comprising a pulse generator having an open-collector or tri-state output connected to an external interrupt line shared by other similar circuits. An active internal interrupt signal causes the pulse generator to pulse. The external interrupt line is fed back and latched on a disabling input of the pulse generator so that any pulse on the external interrupt line prevents further pulsing. The software handler of the interrupt, upon servicing an interrupt of the interrupt level, causes the enabling of the pulse generators of that level, thereby permitting active internal interrupt signals to produce a further pulse. By this interrupt level sharing, phantom interrupts are eliminated and servicing overhead is minimized. R

Interrupt level sharing

In a local area network for data communications, stations which distributively control their access to a common bus or other medium are able to identify the location of any 'hot' station transmitter (one stuck continuously in an 'on' condition which cannot be isolated from the medium). Such networks are effectively disabled by a hot carrier, since each station conditions its access on sensing the medium as previously idle. The present 'loop test' method permits all stations in the network to quickly establish the location of a hot transmitter, and thereby quickly direct field repair personnel to that location. It also permits operators to take action to physically disconnect the faulty transmitter from the medium, so that the other stations may continue to use the network until the fault is repaired.

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Apex, NC, United States of America

William Brooks Ott