BIDI_SET_PORTDRV(19h) stores port driver configuration data. A port driver on a client implements SplPdRemoteSetPort by calling PrtQuery(BIDI_Q_PORTDRV(8019h)). This call gets the port driver configuration from the server. Next, the port driver displays the port configuration and, if the user changes anything, updates the server's port driver settings using PrtSet(BIDI_SET_PORTDRV).