Table 35

+=====-========-========-========-========-========-========-========-========+ 
|  Bit|   7    |   6    |   5    |   4    |   3    |   2    |   1    |   0    |
|Byte |        |        |        |        |        |        |        |        |
|=====+=======================================================================|
| 0   |                           Operation code (18h)                        |
|-----+-----------------------------------------------------------------------|
| 1   | Logical unit number      |              Reserved             |  Pad   |
|-----+-----------------------------------------------------------------------|
| 2   | (MSB)                                                                 |
|-----+---                                                                 ---|
| 3   |                           Parameter list length                       |
|-----+---                                                                 ---|
| 4   |                                                                 (LSB) |
|-----+-----------------------------------------------------------------------|
| 5   |                           Control                                     |
+=============================================================================+