5-6
SCSI Configuration
500300 Rev. U
received after this parameter has been changed, the value in that Mode Select
command takes precedent.
Setting a value of 0 sets the default to the variable block mode.
5.1.13
Buffer (Default = Normal)
The Buffer parameter refers to the use of the one-megabyte buffer.
•
NORMAL
- The buffer is enabled after the drive is powered up. It can be disabled,
and later re-enabled, via a control bit in the MODE SELECT command;
•
FORCE ON
- The buffer will be enabled under all conditions, and the drive will
not respond to the buffer control bit in the Mode Select command;
•
FORCE OFF
- The buffer will be disabled under all conditions, and the drive will
not respond to the buffer control bit in the Mode Select command.
5.1.14
Busy (Default = Not Ready)
This parameter determines how the tape drive responds when it receives a tape
motion command while the tape is rewinding, loading, or security erasing a tape.
•
Not Ready
- The tape drive sets the Check Condition bit in the Completion
Status byte, and a sense key of Not Ready.
•
Busy
- The tape drive sets the Busy bit in the Completion Status byte.
5.1.15
Discon (Default = YES)
The Disconnect parameter allows the tape drive to disconnect from the SCSI bus
during times when the bus would otherwise be idle. This allows other devices to use
the SCSI bus during these times. Certain operations, like REWIND, can take
minutes to perform. If disconnects are not allowed, all other SCSI activity might
have to wait on the tape drive. Note that the SCSI initiator, normally the host
computer, is also allowed to prohibit disconnection on a command–by–command
basis.
•
YES
- Allow disconnection during commands.
•
NO DATA1
- No disconnects within a DATA phase.
•
NO DATA2
- No disconnects within or after a DATA phase (STATUS and
MESSAGE phases).
•
NO
- No disconnects at any time.
5.1.16
Early EOT (Default = Normal)
Depending upon the recording density, the block length, and other conditions when
EOT is detected, the contents of a full buffer (one megabyte) may not fit on the
remaining amount of tape. As an aid in dealing with this situation, the drive informs
