A device and method for enclosure processing of a dual SCSI bus enclosure is described. A single SCSI enclosure processor is provided on an adapter that can operate alone or in pairs to provide different modes of operation, including simplex, duplex, and cluster. When used in pairs, two adapters interconnect internally to the enclosure through internal cross-coupling bus repeaters. The adapters have the ability to automatically configure themselves. In the cluster mode, a first enclosure processor on a first adapter assumes an active status, while a second enclosure processor on a second adapter waits in a standby mode. The standby enclosure processor detects when the active enclosure processor has failed, misoperated, or been removed and automatically failsover, assuming the identity of the active enclosure processor, without disruption to the system. Hot-swapping of the adapter boards is therefore possible.