Using physical devices.
    (Also see Logical_names, and Terminal_environment)

  ALLOCATE          Allocates a device for your exclusive use.
  DEALLOCATE        Releases an allocated device for general use.
  DISMOUNT          Makes a storage device unavailable for processing.
  INITIALIZE        Formats a storage device.
  MOUNT             Makes a storage device available for processing.

  ANALYZE/DISK      Checks the readability and validity of disks.
  ANALYZE/ERROR_LOG Displays the contents of the system error log.
  ANALYZE/MEDIA     Analyzes the format of a storage device.
  BACKUP            Saves or restores files from storage devices.
  SET CARD_READER   Sets the translation mode for a card reader.
  SET DEVICE        Sets device characteristics.
  SET MAGTAPE       Sets magnetic tape device characteristics.
  SET PRINTER       Sets line printer characteristics.
  SET SECURITY
     /CLASS=DEVICE  Modifies the access control list (ACL),
                    protection code, and owner of a device.
  SET VOLUME        Sets mounted volume characteristics.
  SHOW DEVICES      Displays the status of devices.
  SHOW ERROR        Displays device error counts.
  SHOW MAGTAPE      Displays magnetic tape characteristics.
  SHOW PRINTER      Displays line printer characteristics.
  SHOW SECURITY     Displays the name, class, and profile of a device.
                    The profile lists the queue's access control list
                    (ACL), protection code, and owner.
  Type ? to display the list of HINTS.
  Type PHYSICAL_DEVICES to redisplay this particular hint.
  Press the RETURN key before typing a command or topic name.