NAME
    IND_REMHANDLER -- Remove an input handler from the device
FUNCTION
    Remove a function previously added to the list of handler
    functions.
IO REQUEST
    io_Message      mn_ReplyPort set
    io_Device       preset by OpenDevice
    io_Unit         preset by OpenDevice
    io_Command      IND_REMHANDLER
    io_Data         a pointer to the interrupt structure.
NOTES
    This command is not immediate