infoPtr->sysBufWrite = 4096;

    /*
     * Use the pointer to keep the channel names unique, in case the handles
     * are shared between multiple channels (stdin/stdout).
     */

    sprintf(channelName, "file" TCL_I_MODIFIER "x", (size_t)infoPtr);
    sprintf(channelName, "file%" TCL_I_MODIFIER "x", (size_t)infoPtr);

    infoPtr->channel = Tcl_CreateChannel(&serialChannelType, channelName,
	    (ClientData) infoPtr, permissions);


    SetupComm(handle, infoPtr->sysBufRead, infoPtr->sysBufWrite);
    PurgeComm(handle,