148 Commands
SPACE 11h
SPACE provides a variety of positioning functions that are determined by Code
and Count fields in the Command Descriptor Block. Both forward (towards
EOM) and reverse (towards BOM) positioning are provided.
Any unwritten data in the buffer is flushed to tape before the space is started.
The logical media position is then modified according to the Code and Count
fields. Once the space has started, it will complete even if the SCSI operation is
aborted for some reason (for example, the host selects and sends an abort
message).
Pre-Execution Checks:
The Code field must be 0, 1 or 3. If it is not then CHECK CONDITION status is
reported. Sense data will be as described in the Illegal Field Checks.
Command Descriptor Block:
CDB Fields:
Illegal Field Reservation Deferred Error
Unit Attention Media Access Diagnostic Status
7 6 5 4 3 2 1 0
0
Operation Code (11h)
1
Reserved (0) Code
2
(MSB)
Count (n)
3
4
(LSB)
5
Control
Code The Code field indicates what is to be spaced to:
000 Blocks—The number of blocks crossed is dictated by Count.
001 Filemarks—The number of filemarks crossed is dictated by Count.
011 EOD—Space to the end of data in the current active partition.
