Command          Operation
-------          ---------
CMD_FLUSH        Purge all active and queued requests for the input device.

CMD_RESET        Reset the input port to its initialized state.  All
                 active and queued I/O requests will be aborted.  Restarts
                 the device if it has been stopped.

CMD_START        Restart the currently active input (if any) and resume
                 queued I/O requests.

CMD_STOP         Stop any currently active input and prevent queued I/O
                 requests from starting.

ind_addhandler   add an input-stream handler into the handler chain.

ind_remhandler   remove an input-stream handler from the handler chain.

ind_setmport     set the controller port to which the mouse is connected.

ind_setmtrig     set conditions that must be met by a mouse before a
                 pending read request will be satisfied.

ind_setmtype     set the type of device at the mouse port.

ind_setperiod    set the period at which a repeating key repeats.

ind_setthresh    set the repeating key hold-down time before repeat starts.

ind_writeevent   propagate an input event stream to all devices.


Input Device Function
---------------------
peekqualifier()  return the input device's current qualifiers. (v36)


Exec Functions as Used in This Chapter
--------------------------------------
abortio()        abort a command to the input device.

checkio()        return the status of an i/o request.

closedevice()    relinquish use of the input device.

doio()           initiate a command and wait for completion (synchronous
                 request).

opendevice()     obtain shared use of the input device.

sendio()         initiate a command and return immediately (asynchronous
                 request).

Exec Support Functions as Used in This Chapter
----------------------------------------------
createextio()    create an extended i/o request structure of type
                 iostdreq.  this structure will be used to communicate
                 commands to the input device.

createport()     create a signal message port for reply messages from the
                 input device.  Exec will signal a task when a message
                 arrives at the reply port.

deleteextio()    delete an i/o request structure created by createextio().

deleteport()     delete the message port created by createport().