Small computer system with interface control and method of operating same

摘要

Diagnostic data in a sequential access Small Computer System Interface device is accessed by a first logical unit. A second logical unit is configurable to control a mode of operation of the first logical unit. The first unit Provides normal and/or backup functions while the second unit provides diagnostic/status functions or the second unit activates the first unit to be online or offline, depending on the first unit being commanded to perform the diagnostic function.