You can use the following switch for the QNX debugger.

-Console=console_spec
    specifies the virtual console to use for debugger windows.  This may be
    a console number as in the following example.

    Example:

         -console=2

    You may also use a full device name.

    Example:

         -console=//23/dev/ser1

    In this case, the debugger will use that device for it's input and
    output.  The debugger/application screen flipping features will be
    disabled.

    You can also optionally follow the device name with a colon and a
    terminal type.

    Example:

         -con=/dev/ttyp1:vt240

    This will let the debugger know what kind of terminal it's talking to so
    it can initialize the user interface appropriately.

-COlumns=n
    specifies the number of columns of the screen/window that the debugger
    should attempt to establish.

-XConfig=string
    specifies a set of X Windows configuration options to pass to xqsh.