Table 21

+======-========-========-========-========-========-========-========-========+
|   Bit|   7    |   6    |   5    |   4    |   3    |   2    |   1    |   0    |
|Byte  |        |        |        |        |        |        |        |        |
|======+=======================================================================|
| 0    |                           Operation code                              |
|------+-----------------------------------------------------------------------|
| 1    |   Logical unit number    | (MSB)                                      |
|------+------------------------------                                      ---|
| 2    |                           Logical block address (if required)         |
|------+---                                                                 ---|
| 3    |                                                                 (LSB) |
|------+-----------------------------------------------------------------------|
|      |                           Transfer length (if required)               |
| 4    |                           Parameter list length (if required)         |
|      |                           Allocation length (if required)             |
|------+-----------------------------------------------------------------------|
| 5    |                           Control                                     |
+==============================================================================+