Abstract: A repeater (40) for Small Computer System Interface (“SCSI”) buses (52, 54, 56, and 58) to which digital computing devices (62, 64, 66, 68, 72 and 74) connect in parallel. The repeater (40) includes a plurality of bus interface circuits (48) that are connected to the SCSI buses (52, 54, 56 and 58) for receiving signals from and transmitting signals to devices (62, 64, 66, 68, 72 and 74) connected thereto. The bus interface circuits (48) connect to a control circuit (44), that responds to various phases of the SCSI bus protocol: 1. which stores information for use during a subsequent phase of the SCSI bus protocol; and 2. thereby allows signals to be exchanged between pairs of the SCSI buses (52, 54, 56 and 58) during a succession of bus phases occurring on the buses (52, 54, 56 or 58).

Abstract: The technical field of the invention generally concerns digital computers and, in particular, repeaters or switches (40) for distributed arbitration digital data buses (52, 54, 56 and 58) to which devices (62, 64, 66, 68, 72 and 74) connect in parallel. The bus repeater/switch (40) includes a plurality of bus interface cards (48) that are connected to the distributed arbitration buses (52, 54, 56 and 58) for receiving signals from and transmitting signals to devices (62, 64, 66, 68, 72 and 74) connected thereto. The bus interface cards (48) connect to a control card (44) which allows signals from one of the sharing buses (52, 54 or 56) to be exchanged with the shared bus (58). The bus switch (40) also includes selector switch (84 or 88) for choosing which particular one of the sharing buses (52, 54 or 56) exchanges digital data signals with the shared bus (58).