NAME
       CD_SEEK -- position laser at specified location.

   FUNCTION
       CD_SEEK moves the laser to the approximate position specified.  The
       io_Offset field should be set to the offset to which the head is
       to be positioned.

   IO REQUEST INPUT
       io_Device       preset by the call to opendevice()
       io_Unit         preset by the call to opendevice()
       io_Command      CD_SEEK
       io_Offset       position where head is to be moved (always LSN format)

   IO REQUEST RESULT
       io_Error - 0 for success, or an error code as defined in
                  <devices/cd.h>