[ Text to be provided later by our technical writer. ]

  The connection of a media changer to an HSZxx family controller
  is similar to the procedure used for the HSJxx and HSDxx.  The
  main difference is that "ADD PASSTHROUGH" is used in place of
  the "ADD LOADER" command, but the port, target and logical
  numbers must be provided.  The other difference is that pass-
  through device are associated with unit names beginning with
  the letter P instead of D.

  Example:

   For a four drive TL810 family library.

   CLI> ADD PASSTHROUGH TAPE0 5 2 0
   CLI> ADD PASSTHROUGH TAPE1 5 3 0
   CLI> ADD PASSTHROUGH TAPE2 5 4 0
   CLI> ADD PASSTHROUGH TAPE3 5 5 0
   CLI> ADD PASSTHROUGH TL810 5 6 0
   CLI> ADD UNIT P0 TAPE0
   CLI> ADD UNIT P100 TAPE1
   CLI> ADD UNIT P200 TAPE2
   CLI> ADD UNIT P300 TAPE3
   CLI> ADD UNIT P1 TL810

   For a single drive DLT loader with the loader at logical unit 1.

   CLI> ADD PASSTHROUGH DLTtape 6 1 0
   CLI> ADD PASSTHROUGH LOADER  6 1 1
   CLI> ADD UNIT P0 DLTtape
   CLI> ADD UNIT P1 LOADER