Abstract: A system interface includes a plurality of first directors, a plurality of second directors, a data transfer section and a message network. The data transfer section includes a cache memory. The cache memory is coupled to the plurality of first and second directors. The messaging network operates independently of the data transfer section and such network is coupled to the plurality of first directors and the plurality of second directors. The first and second directors control data transfer between the first directors and the second directors in response to messages passing between the first directors and the second directors through the messaging network to facilitate data transfer between first directors and the second directors. The data passes through the cache memory in the data transfer section. A method for operating a data storage system adapted to transfer data between a host computer/server and a bank of disk drives.

Abstract: A system interface includes a plurality of first director boards. Each one of the first director boards has a plurality of first directors and a crossbar switch having input/output ports coupled to the first directors on such one of the first director boards and a pair of output/input ports. The system interface also includes a plurality of second director boards. Each one of the second directors boards has a plurality of second directors and a crossbar switch having input/output ports coupled to the second directors on such one of the second director boards and a pair of output/input ports. A data transfer section is provided having a cache memory. The cache memory is coupled to the plurality of first and second directors. A message network is operative independently of the data transfer section. The message network includes a pair of message network boards. Each one of such message network boards has a switching network having a plurality input/output ports.

Abstract: A system interface includes a plurality of first directors, a plurality of second directors, a data transfer section and a message network. The data transfer section includes a cache memory. The cache memory is coupled to the plurality of first and second directors. The messaging network operates independently of the data transfer section and such network is coupled to the plurality of first directors and the plurality of second directors. The first and second directors control data transfer between the first directors and the second directors in response to messages passing between the first directors and the second directors through the messaging network to facilitate data transfer between first directors and the second directors. The data passes through the cache memory in the data transfer section. A method for operating a data storage system adapted to transfer data between a host computer/server and a bank of disk drives.

Abstract: A system interface includes a plurality of first directors, a plurality of second directors, a data transfer section and a message network. The data transfer section includes a cache memory. The cache memory is coupled to the plurality of first and second directors. The messaging network operates independently of the data transfer section and such network is coupled to the plurality of first directors and the plurality of second directors. The first and second directors control data transfer between the first directors and the second directors in response to messages passing between the first directors and the second directors through the messaging network to facilitate data transfer between first directors and the second directors. The data passes through the cache memory in the data transfer section. A method for operating a data storage system adapted to transfer data between a host computer/server and a bank of disk drives.

Abstract: A direct memory access (DMA) transmitter includes: (a) a data register; and (b) a transmitter state machine. Requested data at an address provided by a source is read from the random access memory then transferred for storage in the data register. The central processing unit also sends a control signal to the transmit state machine. The control signal indicates to the transmit state machine whether the read data is a most recent copy of the requested data in random access memory or whether the most recent copy of the requested data is still resident in the local cache memory. In response to the control signal, if the most recent data is in the local cache memory, the transmit state machine inhibits the data that was read from random access memory and now stored in data register from passing to the transmitter output. Transmit state machine then performs a second data transfer request at the same address, the second requested data being transferred from the local cache memory to the random access memory.

Abstract: A direct memory access (DMA) receiver adapted to receive data from a source, such data to be written into a random access memory is provided. The random access memory and DMA receiver being coupled are to a central processing unit by a bus. The central processing unit is coupled to a local cache memory. The source of such data provides an address for the data, such address being the location the random access memory where the data is to be stored. The DMA receiver includes an address register, a first data register and a duplicate data register. The duplicate register has an input coupled to an output of the first data register. A selector is provided having a pair of inputs, one being coupled to the output of the first data register and another one of the pair of inputs being coupled to an output of the duplicate data register. The selector couples one of the pair of inputs to an output thereof selectively in accordance with a select signal. A state machine is included in the DMA receiver.

Abstract: The pick-up truck box supports a topper made of superimposed upper and lower half portions. The topper half portions are interconnected in edgewise fashion by a connector assembly. This connector assembly is also used as an anchor point for cupboards supported within the enclosure of the topper. The topper side walls are releasably anchored to the truck box side walls by a pivotal handle bar assembly. The latter includes a removable pivotable handle, projecting inside the topper enclosure, and a fulcrum end with an elastomeric pad to frictionally anchor the topper to the truck box. Release of the handle bar lock is possible only from within the topper enclosure.