infoPtr->sysBufWrite = 4096;

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

    snprintf(channelName, 16 + TCL_INTEGER_SPACE, "file%" TCL_Z_MODIFIER "x", (size_t) infoPtr);

    TclWinGenerateChannelName(channelName, "file", infoPtr);
    infoPtr->channel = Tcl_CreateChannel(&serialChannelType, channelName,
	    infoPtr, permissions);


    SetupComm(handle, infoPtr->sysBufRead, infoPtr->sysBufWrite);
    PurgeComm(handle,
	    PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);