Abstract: In data processing systems that use a snoopy based cache coherence protocol and which contain a read only cache memory with a bounded range of addresses, a cache line hit is detected by assuming that, if an address contained in a request falls within the bounded range, the cache line is present in the cache memory for snoop results. This is equivalent to assuming that the cache line is marked as shared when it might not be so marked.

Abstract: A system for servicing communication queues may include memory configured to store a hierarchical channel map having a plurality of levels wherein each bit of the lowest level is mapped to a different one of a plurality of communication channels and wherein each bit of each higher level is mapped to a group of bits at the next lower level. The system may include a host adapter configured to maintain the hierarchical bitmap wherein each bit at the lowest level is set if the channel to which it is mapped has a pending communication request and is cleared if not. Each bit of each higher level is set if at least one bit is set in the lower level group to which is mapped and cleared if not. The host adapter may be configured to examine the hierarchical bitmap in order to determine a next one of the communication channels to service. At each level of the hierarchical channel map a service mask may be provided to track which bits have already been traversed at that level.

Abstract: A fluid operated control valve for controlling fluid flow of a system which includes a first and a second fluid channels therein, the control valve includes: a hollow casing with closed first and second ends; a piston member slidably disposed within the casing and defining thereby within the casing a first chamber adjacent to the first end of the casing and a second chamber adjacent to the second end of the casing; a first magnet disposed adjacent the first chamber of the casing for attracting the piston member to a first terminal position; a second magnet disposed adjacent the second chamber of the casing for attracting the piston member to a second terminal position.

Abstract: In a bundled link system which partitions a data packet into varying size cells, a data packet is partitioned into a stream of cells of which the last two cells are partial cells. When the data has been partitioned so that less than the data required to fill two maximum size cells remains, the remaining data is divided into two cells where the cell size is selected so that each cell is larger than a predetermined minimum size. In a preferred embodiment, the remaining data is equally divided into partial size cells. In particular, in accordance with one embodiment, when there is less than two times the maximum size cell of data remaining to be partitioned in a packet and the remaining data is more than the maximum cell size, then the cell size used for the last two cells is the size of the remaining data divided by two.

Abstract: A method for transmitting messages between two processes includes creating a communications channel between a first channel adapter coupled to a client process and a second channel adapter coupled to a remote process. The method further includes reading a request message at the first channel adapter, segmenting the request message into a series of packets, assigning a sequence number to each packet, and transmitting the packets in order to the second channel adapter through the communications channel. The method further includes receiving the packets at the second channel adapter and sending at least one acknowledgement message to the first channel adapter in response to the received packets.

Abstract: A fluid operated control valve for controlling fluid flow of a system which includes a first and a second fluid channels therein, the control valve includes: a hollow casing with closed first and second ends; a piston member slidably disposed within the casing and defining thereby within the casing a first chamber adjacent to the first end of the casing and a second chamber adjacent to the second end of the casing; a first magnet disposed adjacent the first chamber of the casing for attracting the piston member to a first terminal position; a second magnet disposed adjacent the second chamber of the casing for attracting the piston member to a second terminal position.

Abstract: In a switched configuration in which data links can be bundled to increase data throughput, the links in a bundle are ordered. A data sender sequentially transmits cells in the data packet over links in the bundle. For example, a first cell is transmitted over a first ordered link in the bundle. The next cell is transmitted over the next link in the bundle order and operation continues in a “round robin” fashion. The data receiver is informed in advance of the order of links in the bundle and expects cells to be distributed over the links in that order. The data sender transmits a bundle sequence number with each data cell. As each new data cell is transmitted, the bundle sequence number is incremented. The receiver uses the bundle sequence number to validate cell order, to detect lost cells, and to resynchronize cell order with the sender in the case of cell errors.

Abstract: An electrically powered security system for monitoring and controlling access to a protected area and having multiple levels of alert signal commensurate with the level of security threat to the area; a siren for communicating multiple levels of alert signal, both visual and audible, progressively including: a low level, medium level and full level alert consisting of a voice warnaway, a series of audible chirps, or blinking lights; an electrically erasable and programmable read only memory for permanently storing system operational parameters and a controller for using the operational parameters for controlling the operation of security system, the security system including a remote transmitter to remotely test all input sensors and remotely disable specific sensors from operation, thus having control of any combination of variable audio and/or audio-visual alarm response, the security system further including a light control for automatic light engagement and mutual cooperation with windshield wipers.

Abstract: A fault tolerant computer system includes a fault tolerant data processing module which has means for detecting and correcting errors in the operation of the data processing module to maintain a high degree of data integrity. Data transmission control devices control the transmission of all data to the fault tolerant data processing module and the receipt of all data into the fault tolerant data processing module. Input/output terminals are coupled to the data transmission control means for receiving and transmitting data. A non-fault tolerant input/output module is coupled to transmit the data to the input/output terminals of the fault tolerant data processing module. This module includes a read device for transferring data to the fault tolerant computing system in response to requests from the data transmission control devices, and a firewall for preventing the non-fault tolerant input/output module from initiating transfers of data to the fault tolerant data processing module.