Opening the Serial Port Used by the Printer

I am sending ESC / P codes ( http://webpages.charter.net/dperr/links/esc_p83.htm ) to an Epson LX-300 printer that is connected to COM1 and the computer already has the correct driver installed because someone is need to.

So I wrote this:

using System.IO.Ports;

public class EpsonPrint {

    private char esc = (char)27;
    private char ff = (char)12;

    public static void Main (string[] args) {
        new EpsonPrint();
    }

    public EpsonPrint() {
        SerialPort port = new SerialPort("COM1", 19200, Parity.None, 8,  StopBits.One);
        port.Open();
        port.Write(esc+"@hola mundo!"+ff);
        port.Close();
    }
}

      

        
        
        
      

    

and it works, but only with an Epson driver pointing to a different port or whatever, because if I allow it to use COM1, the code above throws:

"The given port name does not start with COM / com or does not allow a valid serial port.

and for writing it is not a "port already open" error.