This standard defines the protocol requirements of the Automation/Drive Interface - Transport Protocol to allow conforming ADI SCSI devices to inter-operate. The objectives of ADT-2 are: a) to provide a low cost interconnect method between an automation device and the data transfer devices that reside within the media changer (see SMC-3). To standardize this interface such that different disk drives@ tape drives@ optical media drives@ and other SCSI devices may be added to conforming media changers without requiring modifications to generic system hardware; and b) to provide for the addition of special features and functions through the use of vendor-specific options@ reserved areas are provided for future standardization. The interface protocol includes provision for the connection of two SCSI ports. One of these ports is intended to be attached to a media changer device and operates as a SCSI initiator port or as both a SCSI initiator port and a SCSI target port. The other device is intended to be attached to a data transport type device (i.e. a disk drive@ tape drive@ or optical medium device) and operates as a SCSI target port or as both a SCSI initiator port and a SCSI target port This standard defines the transport attributes of an input/output Automation/Drive Interface for interconnecting a conforming media changer device to a conforming data transport device. The set of SCSI standards specifies the interfaces@ functions@ and operations necessary to ensure interoperability between conforming SCSI implementations. This standard is a functional description. Conforming implementations may employ any design technique that does not violate interoperability.