Abstract: A method of providing programmable associativity in a cache used by a processor of a computer system is disclosed. A congruence class of a memory block is defined using a first mapping function, providing a first associativity level of the cache. Program instructions in the processor select a second associativity level of a known appropriate level, and implement the second associativity level in the cache using a second mapping function. Application software may provide the program instructions, wherein the application software has procedures that may result in cache "strides" at particular associativity levels, and the known appropriate level is chosen to lessen memory latencies due to strides. Alternatively, the program instructions may be part of an operating system which monitors memory address requests, determines how efficient a procedure will operate at different associativity levels, and selects a most efficient level for the known appropriate level.

Abstract: A method of providing programmable congruence classes in a cache used by a processor of a computer system is disclosed. Program instructions are loaded in the processor for modifying original addresses of memory blocks in a memory device to produce encoded addresses. A plurality of cache congruence classes is then defined using a mapping function which operates on the encoded addresses, such that the program instructions may be used to arbitrarily assign a given one of the original addresses to a particular one of the cache congruence classes. The program instructions can modify the original addresses by setting a plurality of programmable fields. Application software may provide the program instructions, wherein congruence classes are programmed based on a particular procedure of the application software which is running on the processor, that might otherwise run with excessive "striding" of the cache.

Abstract: A method of providing programmable congruence classes in a cache used by a processor of a computer system is disclosed. A logic unit is connected to the cache for modifying original addresses of memory blocks in a memory device to produce encoded addresses. A plurality of cache congruence classes are then defined using a mapping function which operates on the encoded addresses, such that the logic unit may be used to arbitrarily assign a given one of the original addresses to a particular one of the cache congruence classes. The logic unit can modify the original addresses by setting a plurality of programmable fields. The logic unit also can collect information on cache misses, and modify the original addresses in response to the cache miss information.

Abstract: A method of providing programmable associativity in a cache used by a processor of a computer system is disclosed. A congruence class of a memory block is defined using a first mapping function, providing a first associativity level of the cache. A logic unit connected to the cache monitors cache misses as the cache uses the first associativity level, and selects other associativity levels based on the cache misses, using other mapping functions. The logic unit has incorporated therein means for selecting the other associativity levels based on a rate of the cache misses in a particular congruence class. The congruence class may be defined by associating the memory block with a particular set of cache blocks in the cache, based on a first portion of an address of the memory block, and the other mapping functions may be implemented by dividing the particular set into subsets and selecting a subset for the memory block based on a second portion of the address.

Abstract: A method of improving operation of a cache used by a processor of a computer system by introducing a level of randomness into a replacement algorithm used by the cache in order to lessen "strides" within the cache is disclosed. Different levels of randomness may be introduced into the replacement algorithm at different times to optimize the cache for different procedures running on the processor. The level of randomness can be selectively introduced by using a basic replacement algorithm to select a subset of a congruence class, and one or more random bits are then used to select a specific cache block within the subset for eviction. The basic replacement algorithm can be a least recently used algorithm. There may be three levels of randomness for a 4-way set associative cache, and there may be four levels of randomness for an 8-way set associative cache.

Abstract: An improved system for passenger safety in a front-end vehicle collision, whereby the kinetic energy of a passenger may be reduced before the passenger is exposed to the crash deceleration. An electrical sensor mounted at the extreme front end of the vehicle senses the onset of a front-end collision and sends a crash signal to the passenger compartment. Preferably, the sensor is a normally-closed momentum-activatable switch. A passenger seat is mounted on translating means permitting rearward motion and has a harness to secure a passenger to the seat. The seat is held in place by a shearable pin. Beneath the seat, attached between the floor of the vehicle and the frame of the seat, is a linear actuator powered by an explosive charge which is ignitable electrically in response to the crash signal.

Abstract: A gas mixing valve including a hollow piston slidably lodged within a sleeve. Openings are formed in the piston wall in adjustable alignment with inlet ports in the sleeve, the longitudinal spacing between the openings being substantially equal to the longitudinal spacing between their respective inlet ports. Longitudinal piston movement causes the inlet ports to be progressively blocked, the ratio between the effective unblocked portions of the ports remaining substantially constant. A pressure responsive means such as a diaphragm controls the longitudinal piston position so as to vary the effective portions of the inlet ports inversely to the pressure within the sleeve and piston. The variance in pressure drops across the inlet ports due to changes in the flow rate of the inflowing gases is thereby limited without altering the mixing ratio.

Abstract: Copper sulfide in the presence or absence of metallic copper contained in a dross obtained from the copper drossing of lead bullion is separated from metallic lead entrained or occluded in the dross by introducing the dross into a vessel other than a reverberatory furnace, usually a kettle, also introducing an alkali metal sulfide, preferably sodium sulfide, into the kettle, and heating the dross and alkali metal sulfide together in the kettle at an elevated temperature not in excess of 1200.degree. F. and for a time sufficient to melt together the dross and alkali metal sulfide. The thus-obtained molten dross releases the entrained molten lead which falls to the bottom of the kettle.