Table 251

+=====-========-========-========-========-========-========-========-========+ 
|  Bit|   7    |   6    |   5    |   4    |   3    |   2    |   1    |   0    | 
|Byte |        |        |        |        |        |        |        |        | 
|=====+=======================================================================| 
| 0   |                          Operation code (42h)                         | 
|-----+-----------------------------------------------------------------------| 
| 1   | Logical unit number      |         Reserved         |  MSF   |Reserved| 
|-----+-----------------------------------------------------------------------| 
| 2   |Reserved|  SubQ  |                       Reserved                      | 
|-----+-----------------------------------------------------------------------| 
| 3   |                        Sub-channel data format                        | 
|-----+-----------------------------------------------------------------------| 
| 4   |                               Reserved                                | 
|-----+-----------------------------------------------------------------------| 
| 5   |                               Reserved                                | 
|-----+-----------------------------------------------------------------------| 
| 6   |                             Track number                              | 
|-----+-----------------------------------------------------------------------| 
| 7   | (MSB)                                                                 | 
|-----+---                       Allocation length                         ---| 
| 8   |                                                                 (LSB) | 
|-----+-----------------------------------------------------------------------| 
| 9   |                               Control                                 | 
+=============================================================================+