Something

        static void Main(string[] args)
        {
            SerialStream port = new SerialStream();
            port.SetPortSettings(57600, SerialStream.FlowControl.None, SerialStream.Parity.None, 8, SerialStream.StopBits.One);
            port.Open("COM9");
            StreamReader data = new StreamReader(port);
            Console.WriteLine(data.Read());
            port.Close();
            port.Dispose();
        }