CHIO(1) BSD General Commands Manual CHIO(1)
chio -- medium changer control utility
chio [-f changer] command arg1 arg2 [arg3 [...]]
chio is used to control the operation of medium changers, such as those found in tape and
optical disk jukeboxes.
The options are as follows:
Use the device changer rather than the default device /dev/ch0.
The default changer may be overridden by setting the environment variable CHANGER to the
desired changer device.
A medium changer apparatus is made up of elements. There are four element types: picker
(medium transport), slot (storage), portal (import/export), and drive (data transfer). In
this command description, the shorthand ET will be used to represent an element type, and EU
will be used to represent an element unit. For example, to represent the first robotic arm
in the changer, the ET would be ``picker'' and the EU would be ``0''.
chio move <from ET> <from EU> <to ET> <to EU> [inv]
Moves the media unit from <from ET/EU> to <to ET/EU>. If the optional modifier inv is spec-
ified, the media unit will be inverted before insertion.
chio exchange <src ET> <src EU> <dst1 ET> <dst1 EU> [<dst2 ET> <dst2 ET>] [inv1] [inv2]
Performs a media unit exchange operation. The media unit in <src ET/EU> is moved to <dst1
ET/EU> and the media unit previously in <dst1 ET/EU> is moved to <dst2 ET/EU>. In the case
of a simple exchange, <dst2 ET/EU> is omitted and the values <src ET/EU> are used in their
place. The optional modifiers inv1 and inv2 specify whether the media units are to be
inverted before insertion into <dst1 ET/EU> and <dst2 ET/EU> respectively.
Note that not all medium changers support the exchange operation; The changer must have mul-
tiple free pickers or emulate multiple free pickers with transient storage.
chio position <to ET> <to EU> [inv]
Position the picker in front of the element described by <to ET/EU>. If the optional modi-
fier inv is specified, the media unit will be inverted before insertion.
Note that not all changers behave as expected when issued this command.
Report the number of slots, drives, pickers, and portals in the changer, and which picker
unit the changer is currently configured to use.
Report which picker unit the changer is currently configured to use.
chio setpicker <unit>
Configure the changer to use picker <unit>.
chio status [<type> [unit [count]]] [voltags]
Report the status of all elements in the changer. If <type> is specified, report the status
of all elements of type <type>.
The status bits are defined as follows:
FULL Element contains a media unit.
IMPEXP Media was deposited into element by an outside human operator.
EXCEPT Element is in an abnormal state.
ACCESS Media in this element is accessible by a picker.
EXENAB Element supports passing media (exporting) to an outside human operator.
INENAB Element supports receiving media (importing) from an outside human operator.
If the element is a drive, the device name of the drive will be reported if it is available.
If the [voltags] option is specified, primary and alternate volume tag information will be
reported, if available.
If the previous location of the media is available, it will also be reported.
Perform an INITIALIZE ELEMENT STATUS operation on the changer.
chio cdlu <sub-command> <slot>
This command is provided for controlling CD-ROM changer mechanisms which cannot use the
standard changer control interface. ATAPI CD-ROM changers fall into this category. There
are 3 sub-commands:
load Loads the media from the specified slot into the CD-ROM drive.
unload Unloads the media from the CD-ROM drive and returns it to the specified slot.
abort Aborts any pending load or unload operation.
/dev/ch0 - default changer device
chio -f /dev/ch0 move slot 3 drive 0
Moves the media in slot 3 (fourth slot) to drive 0 (first drive).
chio setpicker 2
Configures the changer to use picker 2 (third picker) for operations.
chio -f /dev/cd0a cdlu load 1
Loads the media from slot (second slot) into the CD-ROM drive.
chio -f /dev/ch1 status
Returns status of all elements in the second changer.
The chio program and SCSI changer driver were originally written by Jason R. Thorpe for And
Communications, http://www.and.com/. Additional development was done by Jason R. Thorpe for
the Numerical Aerospace Simulation Facility, NASA Ames Research Center.
BSD September 8, 1999 BSD