Specifications

ATAPI For Streaming Tape QIC-157 Rev B
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1.6.1. Redundant Command Functionality (Task File vs. Packet)
The SCSI Standard has provided some commands that the ATA Standard also provides. It is the
intent of this specification to allow all the functionality to exist, by utilizing only Command
Packets. This will allow existing SCSI like Drivers to continue to issue packets for all operation,
and has some lower level Driver converting them to the ATAPI protocol.
1.6.2. ATAPI Identify Device vs. INQUIRY
The ATAPI Identify Device command has information that the low level Drivers use to perform
ATA interface hardware configuration. Information in the Identify Device shall continue to look
exactly as the ATA Identify Drive does for compatibility reasons. As the information in the
INQUIRY Command cannot be returned by the ATAPI Identify Device Command, the INQUIRY
Command shall be supported for use by higher level drivers.
1.6.3. Initialize Drive Parameters and Set Features vs. MODE SELECT
The Initialize Drive Parameters command does not contain a method to provide non ATA drive
configuration information, and shall not be used. As such, the MODE SELECT and MODE SENSE
from the SCSI standard shall be supported. The combination of MODE SELECT and Set Features
commands contains all the necessary functionality and is most compatible with the existing BIOS’s
and OS Drivers.