Abstract: An interface controller for a communications network port that includes support for an efficient client/server protocol for exchanging data between client computers and target mass storage devices. The interface controller includes support to allow a server computer to forward a read or write command from a client computer to a target mass storage device containing the identification of a client computer as the source of the read or write command. Interface controller support also allows a clients computer to receive response to messages elicited by a read and write command transmitted to a server computer directly from a target mass storage device by copying the identification of the mass storage target device into a data structure within the interface controller to which subsequent identifications within subsequent data and status messages received from the target mass storage device are compared.

Abstract: A high-performance network/bus multiplexer that exchanges data transfer commands and data between different communications mediums, such as the Fibre Channel and one or more SCSI buses. High-performance is achieved by avoiding transmitting read bus operations through bus bridges, and by limiting contention for buses by connecting Fibre Channel host adapters to a first internal bus and SCSI adapters to a second internal bus.

Abstract: A co-processor works in conjunction with a primary processor which does not natively support co-processing. In a memory which provides instructions for the primary processor, parameters for use by the co-processor are embedded within the instructions. This is done by placing the parameters in fields which are unused by the primary processor. When the primary processor accesses the local memory, the addresses generated by the primary processor are monitored by the co-processor. When the co-processor detects a pre-determined combination within an address generated by the primary processor, the co-processor accesses the data sent from the local memory to the primary processor. The co-processor then extracts the parameters embedded within the unused fields of the accessed data.

Abstract: Entries for data transactions are stored in and accessed from a nexus table. Data transactions over a bus are identified using a first reference. Further, data transactions may be additionally identified using a second reference. When a data transaction is identified only by a first reference, an entry for the data transaction is stored in a location within a first portion of the nexus table. Entries in the first portion of the nexus table are indexed using the first reference for the data transaction. When a data transaction is identified using both a first reference and a second reference, an entry for the data transaction is stored in a location within a second portion of the nexus table. Entries in the second portion of the nexus table are indexed using the second reference number for the data transaction. The first reference is not used in indexing entries in the second portion of the nexus table.