SPACE 6.Command
Specification
SONY AIT-5 drive SDX-1100V series Ver.1.0
6-99
6.27.
SPACE 11h
Bit
Byte
7 6 5 4 3 2 1 0
0
Operation Code (11h)
1
Reserved Code
2
(MSB)
3
Count
4
(LSB)
5
Control
The SPACE command provides a variety of positioning functions that are determined by the Code and Count fields
in the CDB. Both forward (toward EOM/P) and reverse (toward BOM/P) positioning are provided.
Code:
The supported values are:
Table 6-99: SPACE codes
Code Description
000b
001b
011b
100b
Blocks
Filemarks
EOD
Setmarks
Note:
The drive will reject a SPACE Setmark command if it has not configured through MODE SELECT to report
Setmarks. The drive will return a CHECK CONDITION status with the Sense Data set to ILLEGAL REQUEST. In
this command description the word “mark” is used to mean Filemark or Setmark. Only where their responses
differ Filemark and Setmark will be referred explicitly.
Count:
When spacing over blocks or marks, the Count field is interpreted as follows:
A positive value N causes forward movement over N blocks or marks. The tape is logically positioned after the Nth
block (or mark) on the EOM/P side.
A ZERO value causes no change in the logical position.
A negative value -N (2’s complement notation) causes reverse movement over N blocks or marks. The tape is
logically positioned on the BOM /P side of the Nth block (or mark).
When spacing to EOD, the Count field is ignored. Forward movement occurs until the drive encounters EOD.
When executing a SPACE, the drive implements the following hierarchy: Blocks (lowest), Filemarks, Setmarks,
EOD, BOM/P or EOM/P (highest)
Therefore, SPACE N blocks command will terminate with GOOD status after the Nth block, or with a CHECK
CONDITION status on any occurrence of Filemark, Setmark, EOD, BOM/P or EOM/P. SPACE N Filemarks will halt
on the Nth Filemark or on any occurrence of Setmark, EOD, BOM/P or EOM/P, and so on. Within the Sense Data,
the fields will be set as described on the following table.
