Wolf and Alberto,

Thanks for the info on port driving under Win9x.

If you only need TWO output lines at the COM port (RTS and DTR), there is a

way to control these lines via the Windoze API. One could use one line as
clock, >the other as a data line to drive a simple shift register. The shift
clock can be the leading clock edge, and the output strobe can be the
falling edge with a logic "1" >on the data line (thinking of I2C-bus).

I thought there was.   I will try and dig it out as it would be a way of
driving up to 4 tone control lines for those not into soundcard interfacing.

Steve