Extended Messages - IBM Ultrium Internal Tape Drive T200 Reference Manual

Extended Messages

100
Ultrium Internal Tape Drive and 3580 Ultrium Tape Drive: SCSI Reference
Table 114. Supported Extended Messages
Name Code
Synchronous Data
Transfer Request
Wide Data Transfer
Request
01h The default mode is for the drive to never initiate a
Synchronous data transfer negotiation. The initiator is
expected to do so. Since this mode is most important at
power-on, no SCSI method of changing this mode is
provided. Instead, an internal method of changing this
mode is provided (VPD or jumper setting). If the message
is received after selection and before the Command
phase, it then goes to the Message In phase and
responds with a valid response to complete the
negotiation. If the message is received at any other time, a
Message Reject is sent in response, placing the drive data
transfer mode for that initiator to asynchronous.
03h The default mode is for the drive to never initiate a Wide
data transfer negotiation. The initiator is expected to do
so. Since this mode is most important at power-on, no
SCSI method of changing this mode is provided. Instead,
an internal method of changing this mode is provided
(VPD or jumper setting). If the message is received after
selection and before the Command phase, it then goes to
the Message In phase and responds with a valid response
to complete the negotiation. If the message is received at
any other time, a Message Reject is sent in response,
placing the Bus Width to 1 byte wide and data transfer
mode to asynchronous for that initiator.
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