Chapter 4 SCSI Commands
MODE SELECT (6) / (10) Command (15h / 55h)
DLT-S4 Interface Reference Guide
103
Table 64
MODE SELECT
Mode Parameter Header —
Field Descriptions
Field
Description
Medium Type
The drive ignores this field.
Buffered Mode Set to 1 by default. The drive implements immediate reporting on
WRITE
commands
through its buffered mode. With Buffered Mode set to 1, the drive reports
GOOD
status
on
WRITE
commands as soon as the data block has been transferred to the buffer. If
this field is set to 0, the drive does not report
GOOD
status on
WRITE
commands until it
writes the data blocks to tape.
When Buffered Mode is not used, the drive suffers significant performance and
capacity degradation.
Speed
The drive supports a single speed of operation per format. This field must be set to 0h.
Block
Descriptor
Length
Specifies the length in bytes of all the block descriptors. Since the drive only allows one
block descriptor, the value must be either 0 or 8. A value of 0 indicates no block
descriptor is included; a value of 8 indicates a block descriptor is present and precedes
the mode page data.