SPACE
Table 101. SPACE Command
| 7 | 6 | 5 | 4 |
| 3 |
| 2 | 1 | 0 |
|
|
|
|
|
|
|
|
|
| |
0 |
|
|
| Operation Code (11h) |
|
|
| |||
|
|
|
|
|
|
|
|
|
| |
1 | Logical Unit Number (0) | Reserved |
|
| Code |
| ||||
|
|
|
|
|
|
|
|
|
|
|
2 |
|
|
|
|
|
|
|
|
|
|
: |
|
|
|
| Count |
|
|
| ||
4 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
5 |
|
|
|
| Control |
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
The SPACE command instructs the drive to set a new logical position relative to the current logical position. How this is done depends on the value of the Code field and the Count field. The Count field is a signed value that indicates the distance to move. A negative value indicates movement towards BOM; a positive value indicates movement towards EOM.
If the Code field is 000b, then the logical position is moved the number of blocks indicated by the Count field. If a file mark is detected between the current logical position and the requested logical position, the new logical position is set to immediately after the file mark in the direction of the space operation. If BOM or EOD is detected before the requested logical position, then the logical position is set to that position.
If the Code field is 001b, then the logical position is moved the number of file marks indicated by the Count field. If BOM or EOD is detected before the requested logical position, then the logical position is set to that position.
If the Code field is 011b, then the logical position is set to after the last valid block on tape. In this case the Count field is ignored.
Any other value of the Code field causes Check Condition status to be returned. Spacing to sequential file marks is not supported. Set marks are not supported. The Sense Key is set to Illegal Request and the ASC/ASCQ is set to Invalid Field in CDB (2400).
