/* save pointer to bus data */
	bus_array[busnum] = bus;
	rtapi_print_msg(RTAPI_MSG_INFO, "PPMC: bus %d complete\n", busnum);
    }
    for ( n = 0 ; n < MAX_BUS*8 ; n++ ) {
	if ( extradac[n] != -1 ) {
	    rtapi_print_msg(RTAPI_MSG_ERR, "PPMC: no USC/UPC found for extra dac at %02x\n", extradac[n]);
	    rv = -1;
	}
	if ( extradout[n] != -1 ) {
	    rtapi_print_msg(RTAPI_MSG_ERR, "PPMC: no USC/UPC found for extra dig outs at %02x\n", extradout[n]);
	    rv = -1;
	}
    }
    /* restore saved message level */
    rtapi_set_msg_level(msg);