Abstract: A mechanism for avoiding the initiation of control read transactions on a system bus coupling a host system having a host memory and an interface connected to a peripheral unit as data is moved between the host system and the peripheral unit is presented. Control information associated with data memory portions in host memory is written to the interface for data memory portions storing outgoing data and data memory portions to receive incoming data. The interface includes a controller for moving data between the host memory and the interface by first obtaining the control information for the associated data portions. The interface writes status reports in association with the movement of data between the interface and the host memory via the system bus. The mechanism thus enables data transfers to occur via the system without the initiation of control reads in absence of an exception condition.

Abstract: This technical disclosure is for a structurally self-contained, RF-shielded enclosure which is rapidly deployable due to it's ultra light weight and ease of assembly. Assembled by one person in one half hour, the enclosure becomes an RF-shielded, free standing room within an existing non-secure room or environment. Lightweight metallized fabric is sewn together with rugged tent fabric and ballistics cloth. Fiberglass rods are connected to aluminum sleeves and unions to configure the room. A bulkhead assembly penetrates the side wall and provides filtered power and electronic signal interfaces. Honeycomb air guides and an electric fan facilitate air exchange within the room.

Abstract: In a network node having a host system coupled to a network by an adapter, VC-specific congestion is detected and reported to the host system. The host memory includes rx slots or buffers, each corresponding to one of one or more supported slot types. Per-VC slots consumed counters are maintained to count slot consumption for each active VC. Free buffer FIFOs are maintained for each of the one or more slot types, which have a predetermined congestion threshold associated therewith. Entries in each free buffer FIFO correspond to an rx slot posted by the host system. When a new rx slot or buffer in host memory is to be allocated to an incoming cell received on a given VC, the slots consumed counter is compared to the predetermined congestion threshold. If they are equal, the VC is at threshold level and the incoming cell is discarded and a report is sent to the host system.

Abstract: A status report frequency mitigation mechanism for mitigating the frequency of status report generation for raw cells during transmit operations in a network node is presented. The status report frequency mitigation mechanism operates to adjust the frequency with which status reports for raw cells are generated by manipulating the End-of-Packet (EOP) bit in transmit slot descriptors associated with transmit slots containing raw cell data.

Abstract: An apparatus and method for scheduling data transfers between a host and adapter. A schedule table data structure resides in a memory on the adapter. Each location in the schedule table represents a point in time at which data is to be transmitted from the adapter. A current time counter advances at the rate at which data is to be transmitted from the node. A pointer points to successive locations in the schedule table, and advances through the schedule table at a rate faster than the current time counter advances so that the value stored in the pointer represents a point in time which is ahead of the point in time currently represented by the value output from the current time counter. A request for a data transfer between the host and adapter is generated when a valid entry exists at the location pointed to by the pointer. The value of the pointer at the time the request is generated is stored as the last valid time.

Abstract: A mechanism for operating a configurable switch to dynamically (i) route each of the data packets in an ordered string from a particular switch input port through a selected member output port of a hunt group; and (ii) route data packets which need not be transmitted in order from the input ports to available member output ports of the hunt group, as the members become available. A controller assigns each input port a service number, and directs member output ports to handle requests for ordered data packet transmissions from input ports with particular service numbers, such that the ordered transfers from an input port are handled by a single member of each group. The input port broadcasts, through the switch, a request to send ordered data packets through a particular hunt group and includes its service number in the request. The group member assigned to handle ordered transfers from the input port responds by identifying itself.

Abstract: The present invention provides multiple grade, composite cemented carbide articles and a method of making such articles. The cemented carbide articles comprise carbides of different grades (or different compositions and/or microstructures) and, therefore, correspondingly different properties at different locations in the same article. The method of the present invention comprises filling different areas or portions of a die with metallurgical powders having different compositions and/or microstructures. The powder is then compressed as a single compact in the die cavity. The compressed compact is subsequently sintered to produce a multigrade cemented carbide article having composition and/or microstructural variations within the volume of the article.

Abstract: In an interactive video-on-demand system, real-time programs are encoded as a transport stream including a plurality of transport stream packets. Some of the transport stream packets include timing signals indicating the real time of the program. The transport stream packets are formatted into transport cells for transport over an asynchronous transfer mode network from a source to a destination. The cells are transported at a transport rate which is determined by a network clock. The transport rate is chosen to deliver the transport stream faster than the real time of the program. While transporting the transport stream, it is determined if the transport stream is being transported ahead of the real time of the program. In this case, idle cells are injected into the transport stream to have the program arrive at the destination in the real time of the program.

Abstract: A novel mechanism prevents interleaving of packet cells from different source nodes on the same multicast port group at switches of a multicast virtual circuit in a cell-switched network: however, different cells bound for different multicast port groups may be interleaved. The mechanism comprises specific routing information that is stored in each multicast group port entry of a forwarding table located within each switch of the multicast virtual circuit. The forwarding table also stores information relating to each multicast port group including a virtual circuit value for each port of the multicast group. The specific routing information is provided for each multicast port group entry to notify the switch when data traffic for a particular packet is pending through a port of the multicast group and when that data traffic ceases, i.e., when the "end-of-packet" is reached. This ensures that the packets may be correctly reassembled at the destination nodes.

Abstract: A computer system having an arbitration mechanism for controlling the coupling order between a plurality of requesters and a plurality of resources, where each resource has an associated resource type. The arbitration mechanism includes a plurality of request processing units, each associated with one of the plurality of requesters. The request processing units receive resource type request signals from an associated requester. The arbitration mechanism also includes a plurality of grant processing units, each associated with one of the plurality of resources. The grant processing units monitor a status signal from its associated resource. The arbitration mechanism further includes a common broadcast medium which is coupled to all of the request processing units and grant processing units.

Abstract: A packet data communication network employs a local switch, router or bridge device functioning to transfer packets between segments of a larger network. When packets enter this device, an address translation is performed to generate local source and destination addresses which are much shorter than the globally-unique addresses contained in the packet as dictated by the protocol. These local addresses are inserted in a header that is added to the packet, in addition to any header already contained in the packet. This added header travels with the packet through the local switch, router or bridge device, but then is stripped off before the packet is sent out onto another network segment. The added header may also contain other information, such as a local name for the source and destination segment (link), as well as status information that is locally useful, but not part of the packet protocol and not necessary for transmission with the packet throughout the network.

Abstract: An arbitration mechanism for controlling a coupling order between a number of resources and a number of requesters having a number of requests processing units, one associated with each one of the requesters, for receiving a resource type request signal from the associated requester, a number of grant processing units, one associated with each one of the resources, for monitoring a busy status signal from said associated resource, a common broadcast medium coupled to the number of request processing units and the grant processing units, and an arbiter for granting access to said common broadcast medium to one of the request processing units and the grant processing units using the common broadcast medium to control the coupling order between the requesters and the resources in a first come, first served manner.

Abstract: A plug-in logic board for use in an arbitration mechanism is disclosed. The disclosed arbitration mechanism includes two or more request processing units, two or more grant processing units and a common broadcast medium. The request processing units and the grant processing units use the common broadcast medium to control the coupling between requesters and resources on a first come, first served basis. The disclosed logic board includes a request processing unit coupled to the common broadcast medium, a grant processing unit coupled to the common broadcast medium, and an input/output unit coupled to an electronic operating device. The input/output unit passes a resource type request signal from the electronic operating device to the request processing unit, and passes a status signal received from the electronic operating device to the grant processing unit. The input/output unit further outputs a grant signal received from the request processing unit to the electronic operating device.

Abstract: A fast arbiter for handling a large number of types of resources with multiple instances of each type of resource is provided. During a first cycle a request logic circuit broadcasts a request for a preselected type of resource onto a broadcast medium. During a second cycle a grant logic circuit broadcasts a queue position onto the broadcast medium for the preselected type of resource. Also, during the second cycle the request logic circuit stores the queue position. After an asynchronous wait for an instance of the requested type of resource to become free, a third cycle begins wherein the first grant logic circuit broadcasts an indication that a free instance of the preselected type of resource is available. During a fourth cycle the requester is granted access to the free instance of the preselected type of resource.

Abstract: A packet data communication network employs sequence numbers in message packets to identify the packets transmitted for a message, so that the order of packets can be checked, and so that the occurrence of lost or duplicated packets can be detected. A method of keeping track of these sequence numbers is provided. Any number below or above a bounded sequence number acceptance window is ignored (not accepted). Bit maps are established for the range of numbers within the bounded window, each bit representing a sequence number and the bit maps indexed by sequence number. One bit map is a received packet map, used to keep track of which sequence numbers have been received and thus to filter duplicate sequence numbers. An end-of-message bit map is used to record the positions of packets having end-of-message flags, and this is used with the received packet map to determine whether all packets of a message have been received, so that an end-of-message trigger can be generated.

Abstract: An improved drill bit for wood boring or boring in other relatively soft material, having a generally cylindrical shaft (20), with a flattened blade portion at one end (24). The blade portion (24) is broad and flat with essentially parallel side surfaces (41, 42) and having negatively beveled edges along the length of such side surfaces, such side surfaces giving way to a modified end edge. The modified end edge includes a center point, with a length of one half to several times the thickness of the blade, and said point (34) is centered on the end edge and is made with a triangular shape with a vee groove from the center of the base to the middle of the vertex. (35). Outer spurs of rectangular cross section (29 and 30) with a concave tip and a negative bevel away from the leading edge are located on the lateral extremities of the end edge.

Abstract: An improved drill bit for wood boring or boring in other relatively soft material, having a generally cylindrical shaft (20), with a flattened blade portion at one end (24). The blade portion (24) is broad and flat with essentially parallel side surfaces (41,42) and having negatively beveled edges along the length of such side surfaces, such side surfaces giving way to a modified end edge. The modified end edge includes a center spur that is of rectangular cross section, with a length of one half to several times the thickness of the blade, and said spur (34) is centered on the end edge and is made with a concave tip (35). The edges of the center spur are parallel from vertex (36) to base. Outer spurs of rectangular cross section (29 and 30) with a negative bevel away from the leading edge are located on the lateral extremities of the end edge.

Abstract: A data coding method for digital communication systems is disclosed. In two embodiments, every four bits of data in a first data channel are mapped to a five bit code symbol. The five bit code symbols are chosen to have a duty cycle of 40 to 60 percent. In the first embodiment, a second channel of data is optionally interleaved with the encoded first channel data by placing single bits from the second channel every sixth bit in the data stream between each five bit code symbol. A plurality of synchronizing words are each formed from other pairs of five bit code symbols, and, in the two channel embodiment, the optional two bits of data from the second channel. The synchronizing words also have a duty cycle of 40 to 60 percent, and further have the characteristic that their bit patterns can only occur where they are placed in a stream of encoded data.

Abstract: A suitcase is modified to have wheels at the bottom corners of the rear face of the suitcase, a retractable handle with an offset to secure stacked luggage against the offset, and a spring actuated folding shelf which can grip adjacent luggage items. The offset handle can be used for normal lifting when retracted and pulling when extended. Offset allows extension structure to be placed in the rear wall of the suitcase while the handle is placed in the normal central location. The offset also lowers the center of gravity of the combination, especially when other items of luggage are stacked on the extensible handle. The shelf is incorporated into the front wall, and can be folded out and down to support adjacent luggage. The shelf is spring loaded towards the closed (flush with suitcase) position, in order to secure the shelf when not in use and to grip adjacent luggage when the shelf is deployed.