Absolute_Addresses

   The operating system interface routines use absolute SCSI element
   addresses, instead of zero relative address as used by the higher
   level functions. A zero based element address can be converted to
   an absolute address by adding the element base address from the
   robot_info_t structure. For example, the absolute slot address
   can be found by adding slot_start to the relative slot address:

    int  slot ;
    robot_info_t robot_info ;

    /*
     * An relative starting address.
     */
    slot = 3 ;

    /*
     * Becoming an absolute address.
     */
    slot += robot_info.slot_start ;