Abstract: The invention greatly reduces common bus contention by allowing the semaphore test bit and set operations to be performed on each CPU's local bus. The semaphore lock bits are stored locally in high speed SRAM on each CPU, and coherency of the lock bits is maintained through a bus monitoring logic circuit on each CPU. A CPU wishing to take possession of a semaphore performs a local read of its semaphore memory, and spins locally until the lock bit is reset at which time it performs a local write to set the bit. When the semaphore lock bit is written, it will be updated locally, and at the same time the write operation will be sent out over the common bus. The bus monitoring logic on every other CPU will recognize the write operation and simultaneously update the corresponding lock bit in each local semaphore memory. This ability to read spin locally relieves the common bus from the great amount of traffic that occurs in typical systems that maintain the semaphore lock bits in common global memory.

Abstract: A method for selecting the sizes and the ordering of the extents used to construct a file, a segment, or a virtual space of a computer system (file). The general method is defined to be any function, applied to this purpose, that, in general, attaches larger extents to the larger file addresses, and for which the selection of extent sizes is determined only by the address an extent is to reside at in the file, plus any tuning parameters. The method results in files which are mostly contiguous, and that stay mostly contiguous, irrespective of any growth or shrinkage the file may be subjected to during its lifetime. High contiguity improves performance by permitting a compact file representation, and, for disc files, improves performance by permitting larger blocks of data to be moved to or from the disc device, and by minimizing head seeks.

Abstract: A method of storing data on a peripheral rotating disk memory system, which is connected to one of a plurality of central processor units via a common bus including temporarily storing, in an intermediate memory system connected to the bus, original data packets which are to be stored in the disk memory system separating data block and commands of the original data packets received by the intermediate memory system from each other, creating composite data packets containing a new command and all data of a number of original data packets received by the intermediate memory system, writing the composite data packets via the bus on the rotating disk memory device, and purging the intermediate memory system after completing a write operation.

Abstract: The use of a redundant memory subsystem, memory flow control, and a method of copying (srubbing) data from the location of one memory subsystem to the corresponding location in the other memory subsystem provides correction of soft errors in a parity protected memory system without degrading the performance of the memory system except when an error occurs. A copy of the correct data is also provided to the memory system when a location in either of the memory subsystems experiences a hard error.

Abstract: In a multiprocessor system with a common bus and a central arbitration controller, which samples the request status of every system agent, the arbitration controller grants bus accesses based on an arbitration scheme consisting of two rotating queues with a fixed priority between the queues.

Abstract: In a device with openings for receiving pins of electrical components therein an including spring elements which are bowed in toward the center of the opening at the bottom thereof, and is then bowed out in the middle of the opening and drawn back towards the center of the opening at the top to form a funnel for receiving one of the pins.