NAME
        SelectOutput -- Select a filehandle as the default output channel (V36)

   SYNOPSIS
        old_fh = SelectOutput(fh)
        D0                    D1

        bptr selectoutput(bptr)

   FUNCTION
        Set the current output as the default output for the process.
        This changes the value returned by output().  old_fh should
        be closed or saved as needed.

   INPUTS
        fh     - Newly desired output handle

   RESULT
        old_fh - Previous current output

   SEE ALSO
        output(), selectinput(), input()