https://svn.boost.org/trac10/ticket/9277 <p> 9600 8N1 Transmit only, both DSR and CTS asserted by device (printer). Behavior is apparently no different than handshake none. Works fine with windows-specific code which sets the DCB as follows: </p> <pre class="wiki">dcb.fOutxCtsFlow = true; // Enable CTS monitoring dcb.fOutxDsrFlow = true; // Enable DSR monitoring dcb.fDtrControl = DTR_CONTROL_HANDSHAKE; // Enable DTR handshaking dcb.fOutX = false; // Disable XON/XOFF for transmission dcb.fInX = false; // Disable XON/XOFF for receiving dcb.fRtsControl = RTS_CONTROL_HANDSHAKE; // Enable RTS handshaking </pre><p> Couldn't find where the DCB is set in asio... </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/9277 Trac 1.4.3