Abstract: The disk drive provides a method of adaptively managing a cache segment divided into chunks by defining an unavailable data type to be stored in an element of a chunk array which indicates that the chunk is not available, and defining an available data type to be stored in an element of the chunk array that indicates the chunk is available and that indicates the number of consecutive chunks that are available. The disk drive also computes a number of chunks needed to fit the request length and scans the chunk array to find a first available element whose available data type meets a predetermined criteria for the number of chunks needed to fit the request length.

Abstract: The disk drive provides a method of adaptively managing a cache segment divided into chunks by defining an unavailable data type to be stored in an element of a chunk array which indicates that the chunk is not available, and defining an available data type to be stored in an element of the chunk array that indicates the chunk is available and that indicates the number of consecutive chunks that are available. The disk drive also computes a number of chunks needed to fit the request length and scans the chunk array to find a first available element whose available data type meets a predetermined criteria for the number of chunks needed to fit the request length.

Abstract: A method provides for waiting for a cache hit in the operation of a disk drive. The drive has an intelligent interface for communicating with a host, a magnetic disk, and a cache. The cache is divisible into a number of segments, and the cache employs a cache control structure. The drive receives a first command and a second command wherein the second command has a requested data range. The method comprises the steps of: (a) initializing a read in response to the first command to provide prefetch data to the cache in a prefetch data range wherein the prefetch data range has a first logical block address; and (b) waiting for a cache hit in response to the second command wherein the beginning of the requested data is within the prefetch data range and does not request the first logical block address.

Abstract: A method for processing interface messages, such as SCSI messages, using an indexed jump table. Two single-dimensional tables are implemented by the method described. The first table stores index values for all valid sequence instruction locations for which an ATN signal can be detected. The second table stores index values for all valid interface messages. The index values of these two tables are used as entry points to the indexed jump table whose elements contain addresses to message handling functions.

Abstract: An improved method and apparatus for recognizing, classifying and processing frames received at a frame processor in a computer network is disclosed. Following receipt of a frame at an input port of a frame processor, source and destination addresses are parsed from the frame. A plurality of lookup tables are provided in a memory, each of which contains a search field and a classification key field. Source or destination addresses are stored in the respective search fields along with other information associated with the frame and a compact classification key is stored in the corresponding classification key field. Searches are performed of the respective search fields within the respective lookup tables to determine whether a match exists between the each of the destination and source addresses and other information and the search field within the lookup tables. In the event the searches yield a match, a classification key associated with each respective address is retrieved.

Abstract: Digital logic equipment in which two logic elements operate with timing control from a clock element with selected synchronism, includes a failure detecting element which detects the absence of the selected synchronism between the two logic elements even when each is providing otherwise correct logic operation. The apparatus and method enable a digital logic system to follow two redundant digital logic elements so long as they operate in lock step synchronism, and to sense a failure which occurs only in synchronism to disable one of the two logic elements to maintain thereafter uninterrupted operation with the other logic element.

Abstract: A seat integrated seat belt system. A three point seat belt system includes a belt having one end affixed to the seat and an opposite end mounted to a retractor secured to the seat. A seat belt tongue is mounted to the belt intermediate the belt ends and is releasably lockable with a belt buckle on the opposite side of the seat thereby pulling one portion of the belt across the passenger lap and another portion of the belt across the passenger upper torso. The belt extends through a guide located at the top of the seat. A seat tether includes a second belt having one end attached to the seat at the location of the guide and a second end mounted to a second retractor located beneath the seat. The second retractor is operable to limit motion of the seat thereby minimizing the impact of vehicle motion on the first belt securing the passenger to the seat.

Abstract: A seat belt system which incorporates a seat belt assembly including a buckle and mounting brackets, a tongue, a retractor, and webbed belting is disclosed in combination with a member for collecting a predetermined amount of slack in the system in lieu of its collection by the retractor. The member for collecting slack having a relatively retracted first position and a relatively extended second position and including a feature to urge the member to the first position. The application of an external force of sufficient magnitude causes the member to move to the second position, but when the force is withdrawn, the member returns to the first position. When used in a system which also incorporates a retractor assembly, the seat buckle assembly overcomes the tendency of the system to cinch down on the user.

Abstract: A computer system of the type having a processor section, a memory section, an input-output section, a system clock, and a system bus for communicating signals between the sections, accommodates a variable number of processor units in the processor section. The processor section hence is expandable. Synchronization is distributed in that each processor unit can synchronize all the units in the processor section. The processor units arbitrate for access to the system bus, and respond to interrupts, on a distributed basis. A distribution counter in each processor unit provides a periodically sequencing unique count to distribute tasks among the processor units.

Abstract: A method and apparatus for performing high speed graphics fill is provided. Any closed line geometric shape or polygon that can be defined by pixel position is stored in memory. The memory pixel positions are stored in address locations corresponding to row and column positions. A first sequential examination of the data is made in reverse raster scan order to make a preliminary determination of the pixel positions inside the closed polygon. A second sequential examination of the data is made in forward or regular raster scan order and a final determination is made whether the pixel positions are inside the polygon and shall be filled. The final determination of pixel positions to be filled is stored shortly before the graphics fill operation is performed so that the fill operation is performed in raster scan time at high speed.

Abstract: A magnetic bubble domain device including a magnetoresistive element for detecting the presence of bubble domains which are stretched in a direction orthogonal to the propagation direction of the bubble domains.