diff --git a/pico_tnc/tnc.h b/pico_tnc/tnc.h
index 640d634..e729a41 100644
--- a/pico_tnc/tnc.h
+++ b/pico_tnc/tnc.h
@@ -1,29 +1,8 @@
-/*
-Copyright (c) 2021, JN1DFF
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-* Redistributions of source code must retain the above copyright notice, 
-  this list of conditions and the following disclaimer.
-* Redistributions in binary form must reproduce the above copyright notice, 
-  this list of conditions and the following disclaimer in the documentation 
-  and/or other materials provided with the distribution.
-* Neither the name of the <organization> nor the names of its contributors 
-  may be used to endorse or promote products derived from this software 
-  without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
-DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-*/
+/**
+ * Copyright (c) 2021 JN1DFF
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
 
 #pragma once
 #include "pico/util/queue.h"
@@ -33,7 +12,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //#include "cmd.h"
 
 // number of ports
-#define PORT_N 3    // number of ports, 1..3
+#define PORT_N 1    // number of ports, 1..3
 
 #define BAUD_RATE 1200
 #define SAMPLING_N 11