diff --git a/CWIdTX.cpp b/CWIdTX.cpp
index 641b374..aef04b0 100644
--- a/CWIdTX.cpp
+++ b/CWIdTX.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -125,7 +125,7 @@ void CCWIdTX::process()
   }
 }
 
-uint8_t CCWIdTX::write(const uint8_t* data, uint8_t length)
+uint8_t CCWIdTX::write(const uint8_t* data, uint16_t length)
 {
   ::memset(m_poBuffer, 0x00U, 1000U * sizeof(uint8_t));
 
diff --git a/CWIdTX.h b/CWIdTX.h
index 70f67ea..a0480e0 100644
--- a/CWIdTX.h
+++ b/CWIdTX.h
@@ -1,6 +1,6 @@
 /*
  *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
- *   Copyright (C) 2016 by Colin Durbridge G4EML
+ *   Copyright (C) 2016,2020 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -28,7 +28,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
   void reset();
 
diff --git a/CalDMR.cpp b/CalDMR.cpp
index 5a92fb0..949a8e9 100644
--- a/CalDMR.cpp
+++ b/CalDMR.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -208,7 +208,7 @@ void CCalDMR::dmrdmo1k()
   }
 }
 
-uint8_t CCalDMR::write(const uint8_t* data, uint8_t length)
+uint8_t CCalDMR::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
diff --git a/CalDMR.h b/CalDMR.h
index 06ff6e6..9ba5f2c 100644
--- a/CalDMR.h
+++ b/CalDMR.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -41,7 +41,7 @@ public:
   void createData1k(uint8_t n);
   void createDataDMO1k(uint8_t n);
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;
diff --git a/CalDStarTX.cpp b/CalDStarTX.cpp
index 1c1a3a4..9680cdc 100644
--- a/CalDStarTX.cpp
+++ b/CalDStarTX.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -162,7 +162,7 @@ void CCalDStarTX::process()
   m_count = (m_count + 1U) % (30U * 21U);
 }
 
-uint8_t CCalDStarTX::write(const uint8_t* data, uint8_t length)
+uint8_t CCalDStarTX::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
diff --git a/CalDStarTX.h b/CalDStarTX.h
index c411317..86f6625 100644
--- a/CalDStarTX.h
+++ b/CalDStarTX.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -26,7 +26,7 @@ class CCalDStarTX {
 public:
   CCalDStarTX();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
   void process();
 
diff --git a/CalFM.cpp b/CalFM.cpp
index e89f0be..9841725 100644
--- a/CalFM.cpp
+++ b/CalFM.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2020 by Phil Taylor M0VSE
  *
@@ -116,7 +116,7 @@ void CCalFM::process()
 }
 
 
-uint8_t CCalFM::write(const uint8_t* data, uint8_t length)
+uint8_t CCalFM::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
diff --git a/CalFM.h b/CalFM.h
index 0dd8887..9665bcc 100644
--- a/CalFM.h
+++ b/CalFM.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2020 by Phil Taylor M0VSE
  *
@@ -35,7 +35,7 @@ public:
   void fm25kcal();
   void fm30kcal();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   uint16_t  m_frequency;
diff --git a/CalNXDN.cpp b/CalNXDN.cpp
index c223f59..3e46f3e 100644
--- a/CalNXDN.cpp
+++ b/CalNXDN.cpp
@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -79,7 +80,7 @@ void CCalNXDN::process()
   }
 }
 
-uint8_t CCalNXDN::write(const uint8_t* data, uint8_t length)
+uint8_t CCalNXDN::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
diff --git a/CalNXDN.h b/CalNXDN.h
index f0051ef..cad88a4 100644
--- a/CalNXDN.h
+++ b/CalNXDN.h
@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -32,7 +33,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;
diff --git a/CalP25.cpp b/CalP25.cpp
index b1b9b6d..6f3d4c0 100644
--- a/CalP25.cpp
+++ b/CalP25.cpp
@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -82,7 +83,7 @@ void CCalP25::process()
   }
 }
 
-uint8_t CCalP25::write(const uint8_t* data, uint8_t length)
+uint8_t CCalP25::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
diff --git a/CalP25.h b/CalP25.h
index 6374ed2..75bfe0d 100644
--- a/CalP25.h
+++ b/CalP25.h
@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -34,7 +35,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;
diff --git a/CalPOCSAG.cpp b/CalPOCSAG.cpp
index bf88a51..b66eb69 100644
--- a/CalPOCSAG.cpp
+++ b/CalPOCSAG.cpp
@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2019 by Florian Wolters DF2ET
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -38,7 +39,7 @@ void CCalPOCSAG::process()
   pocsagTX.writeByte(0xAAU);
 }
 
-uint8_t CCalPOCSAG::write(const uint8_t* data, uint8_t length)
+uint8_t CCalPOCSAG::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
diff --git a/CalPOCSAG.h b/CalPOCSAG.h
index 291e360..d49eb81 100644
--- a/CalPOCSAG.h
+++ b/CalPOCSAG.h
@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2019 by Florian Wolters DF2ET
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -32,7 +33,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   POCSAGCAL m_state;
diff --git a/DMRDMOTX.cpp b/DMRDMOTX.cpp
index 141ed38..ca3159c 100644
--- a/DMRDMOTX.cpp
+++ b/DMRDMOTX.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
@@ -104,7 +104,7 @@ void CDMRDMOTX::process()
   }
 }
 
-uint8_t CDMRDMOTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CDMRDMOTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;
diff --git a/DMRDMOTX.h b/DMRDMOTX.h
index 62ef2c1..076212d 100644
--- a/DMRDMOTX.h
+++ b/DMRDMOTX.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -29,7 +29,7 @@ class CDMRDMOTX {
 public:
   CDMRDMOTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
diff --git a/DMRTX.cpp b/DMRTX.cpp
index 81437ec..21bfb44 100644
--- a/DMRTX.cpp
+++ b/DMRTX.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
@@ -144,7 +144,7 @@ void CDMRTX::process()
   }
 }
 
-uint8_t CDMRTX::writeData1(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeData1(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -168,7 +168,7 @@ uint8_t CDMRTX::writeData1(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeData2(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeData2(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -192,7 +192,7 @@ uint8_t CDMRTX::writeData2(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint16_t length)
 {
   if (length != 9U)
     return 4U;
@@ -208,7 +208,7 @@ uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeAbort(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeAbort(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
diff --git a/DMRTX.h b/DMRTX.h
index 1e2f617..ef7fdcb 100644
--- a/DMRTX.h
+++ b/DMRTX.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -38,11 +38,11 @@ class CDMRTX {
 public:
   CDMRTX();
 
-  uint8_t writeData1(const uint8_t* data, uint8_t length);
-  uint8_t writeData2(const uint8_t* data, uint8_t length);
+  uint8_t writeData1(const uint8_t* data, uint16_t length);
+  uint8_t writeData2(const uint8_t* data, uint16_t length);
 
-  uint8_t writeShortLC(const uint8_t* data, uint8_t length);
-  uint8_t writeAbort(const uint8_t* data, uint8_t length);
+  uint8_t writeShortLC(const uint8_t* data, uint16_t length);
+  uint8_t writeAbort(const uint8_t* data, uint16_t length);
 
   void setStart(bool start);
   void setCal(bool start);
diff --git a/DStarTX.cpp b/DStarTX.cpp
index 63eb910..e1dc81c 100644
--- a/DStarTX.cpp
+++ b/DStarTX.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -277,7 +277,7 @@ void CDStarTX::process()
   }
 }
 
-uint8_t CDStarTX::writeHeader(const uint8_t* header, uint8_t length)
+uint8_t CDStarTX::writeHeader(const uint8_t* header, uint16_t length)
 {
   if (length != DSTAR_HEADER_LENGTH_BYTES)
     return 4U;
@@ -296,7 +296,7 @@ uint8_t CDStarTX::writeHeader(const uint8_t* header, uint8_t length)
   return 0U;
 }
 
-uint8_t CDStarTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CDStarTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != DSTAR_DATA_LENGTH_BYTES)
     return 4U;
diff --git a/DStarTX.h b/DStarTX.h
index 24876d7..8470746 100644
--- a/DStarTX.h
+++ b/DStarTX.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -27,8 +27,8 @@ class CDStarTX {
 public:
   CDStarTX();
 
-  uint8_t writeHeader(const uint8_t* header, uint8_t length);
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeHeader(const uint8_t* header, uint16_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
   uint8_t writeEOT();
 
   void process();
diff --git a/NXDNTX.cpp b/NXDNTX.cpp
index b6ef616..9aba8ef 100644
--- a/NXDNTX.cpp
+++ b/NXDNTX.cpp
@@ -122,7 +122,7 @@ void CNXDNTX::process()
   }
 }
 
-uint8_t CNXDNTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CNXDNTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != (NXDN_FRAME_LENGTH_BYTES + 1U))
     return 4U;
diff --git a/NXDNTX.h b/NXDNTX.h
index bd65818..7c4f937 100644
--- a/NXDNTX.h
+++ b/NXDNTX.h
@@ -27,7 +27,7 @@ class CNXDNTX {
 public:
   CNXDNTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
diff --git a/P25TX.cpp b/P25TX.cpp
index 009a0f2..76dfe3c 100644
--- a/P25TX.cpp
+++ b/P25TX.cpp
@@ -118,7 +118,7 @@ void CP25TX::process()
   }
 }
 
-uint8_t CP25TX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CP25TX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length < (P25_TERM_FRAME_LENGTH_BYTES + 1U))
     return 4U;
diff --git a/P25TX.h b/P25TX.h
index a7cd27d..45bd05a 100644
--- a/P25TX.h
+++ b/P25TX.h
@@ -27,7 +27,7 @@ class CP25TX {
 public:
   CP25TX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
diff --git a/POCSAGTX.cpp b/POCSAGTX.cpp
index d53f9b7..e673e01 100644
--- a/POCSAGTX.cpp
+++ b/POCSAGTX.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2018 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2018,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -95,7 +95,7 @@ bool CPOCSAGTX::busy()
     return false;
 }
 
-uint8_t CPOCSAGTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CPOCSAGTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != POCSAG_FRAME_LENGTH_BYTES)
     return 4U;
diff --git a/POCSAGTX.h b/POCSAGTX.h
index d640862..1fe9bbb 100644
--- a/POCSAGTX.h
+++ b/POCSAGTX.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015-2019 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015-2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -27,7 +27,7 @@ class CPOCSAGTX {
 public:
   CPOCSAGTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void writeByte(uint8_t c);
 
diff --git a/SerialPort.cpp b/SerialPort.cpp
index 65ad4c2..b1775b8 100644
--- a/SerialPort.cpp
+++ b/SerialPort.cpp
@@ -266,7 +266,7 @@ void CSerialPort::getVersion()
   writeInt(1U, reply, count);
 }
 
-uint8_t CSerialPort::setConfig(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setConfig(const uint8_t* data, uint16_t length)
 {
   if (length < 21U)
     return 4U;
@@ -376,7 +376,7 @@ uint8_t CSerialPort::setConfig(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CSerialPort::setFMParams1(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setFMParams1(const uint8_t* data, uint16_t length)
 {
   if (length < 8U)
     return 4U;
@@ -401,7 +401,7 @@ uint8_t CSerialPort::setFMParams1(const uint8_t* data, uint8_t length)
   return fm.setCallsign(callsign, speed, frequency, time, holdoff, highLevel, lowLevel, callAtStart, callAtEnd, callAtLatch);
 }
 
-uint8_t CSerialPort::setFMParams2(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setFMParams2(const uint8_t* data, uint16_t length)
 {
   if (length < 6U)
     return 4U;
@@ -421,7 +421,7 @@ uint8_t CSerialPort::setFMParams2(const uint8_t* data, uint8_t length)
   return fm.setAck(ack, speed, frequency, minTime, delay, level);
 }
 
-uint8_t CSerialPort::setFMParams3(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setFMParams3(const uint8_t* data, uint16_t length)
 {
   if (length < 12U)
     return 4U;
@@ -447,7 +447,7 @@ uint8_t CSerialPort::setFMParams3(const uint8_t* data, uint8_t length)
   return fm.setMisc(timeout, timeoutLevel, ctcssFrequency, ctcssHighThreshold, ctcssLowThreshold, ctcssLevel, kerchunkTime, hangTime, useCOS, cosInvert, rfAudioBoost, maxDev, rxLevel);
 }
 
-uint8_t CSerialPort::setMode(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setMode(const uint8_t* data, uint16_t length)
 {
   if (length < 1U)
     return 4U;
@@ -598,321 +598,33 @@ void CSerialPort::process()
         m_buffer[0U] = c;
         m_ptr = 1U;
         m_len = 0U;
-      }
-      else {
+      } else {
         m_ptr = 0U;
         m_len = 0U;
       }
     } else if (m_ptr == 1U) {
-      // Handle the frame length
+      // Handle the frame length, 1/2
       m_len = m_buffer[m_ptr] = c;
       m_ptr = 2U;
+    } else if (m_ptr == 2U) {
+      // Handle the frame length, 2/2
+      m_buffer[m_ptr] = c;
+      m_ptr = 3U;
+
+      if (m_len == 0U)
+        m_len = c + 255U;
+
+      // The full packet has been received, process it
+      if (m_ptr == m_len)
+        processMessage();
     } else {
       // Any other bytes are added to the buffer
       m_buffer[m_ptr] = c;
       m_ptr++;
 
       // The full packet has been received, process it
-      if (m_ptr == m_len) {
-        uint8_t err = 2U;
-
-        switch (m_buffer[2U]) {
-          case MMDVM_GET_STATUS:
-            getStatus();
-            break;
-
-          case MMDVM_GET_VERSION:
-            getVersion();
-            break;
-
-          case MMDVM_SET_CONFIG:
-            err = setConfig(m_buffer + 3U, m_len - 3U);
-            if (err == 0U)
-              sendACK();
-            else
-              sendNAK(err);
-            break;
-
-          case MMDVM_SET_MODE:
-            err = setMode(m_buffer + 3U, m_len - 3U);
-            if (err == 0U)
-              sendACK();
-            else
-              sendNAK(err);
-            break;
-
-          case MMDVM_SET_FREQ:
-            sendACK();
-            break;
-
-          case MMDVM_FM_PARAMS1:
-            err = setFMParams1(m_buffer + 3U, m_len - 3U);
-            if (err == 0U) {
-              sendACK();
-            } else {
-              DEBUG2("Received invalid FM params 1", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_FM_PARAMS2:
-            err = setFMParams2(m_buffer + 3U, m_len - 3U);
-            if (err == 0U) {
-              sendACK();
-            } else {
-              DEBUG2("Received invalid FM params 2", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_FM_PARAMS3:
-            err = setFMParams3(m_buffer + 3U, m_len - 3U);
-            if (err == 0U) {
-              sendACK();
-            } else {
-              DEBUG2("Received invalid FM params 3", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_CAL_DATA:
-            if (m_modemState == STATE_DSTARCAL)
-              err = calDStarTX.write(m_buffer + 3U, m_len - 3U);
-            if (m_modemState == STATE_DMRCAL || m_modemState == STATE_LFCAL || m_modemState == STATE_DMRCAL1K || m_modemState == STATE_DMRDMO1K)
-              err = calDMR.write(m_buffer + 3U, m_len - 3U);
-            if (m_modemState == STATE_FMCAL10K || m_modemState == STATE_FMCAL12K || m_modemState == STATE_FMCAL15K || m_modemState == STATE_FMCAL20K || m_modemState == STATE_FMCAL25K || m_modemState == STATE_FMCAL30K)
-              err = calFM.write(m_buffer + 3U, m_len - 3U);
-            if (m_modemState == STATE_P25CAL1K)
-              err = calP25.write(m_buffer + 3U, m_len - 3U);
-            if (m_modemState == STATE_NXDNCAL1K)
-              err = calNXDN.write(m_buffer + 3U, m_len - 3U);
-            if (m_modemState == STATE_POCSAGCAL)
-              err = calPOCSAG.write(m_buffer + 3U, m_len - 3U);
-            if (err == 0U) {
-              sendACK();
-            } else {
-              DEBUG2("Received invalid calibration data", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_SEND_CWID:
-            err = 5U;
-            if (m_modemState == STATE_IDLE)
-              err = cwIdTX.write(m_buffer + 3U, m_len - 3U);
-            if (err != 0U) {
-              DEBUG2("Invalid CW Id data", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_DSTAR_HEADER:
-            if (m_dstarEnable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_DSTAR)
-                err = dstarTX.writeHeader(m_buffer + 3U, m_len - 3U);
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_DSTAR);
-            } else {
-              DEBUG2("Received invalid D-Star header", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_DSTAR_DATA:
-            if (m_dstarEnable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_DSTAR)
-                err = dstarTX.writeData(m_buffer + 3U, m_len - 3U);
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_DSTAR);
-            } else {
-              DEBUG2("Received invalid D-Star data", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_DSTAR_EOT:
-            if (m_dstarEnable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_DSTAR)
-                err = dstarTX.writeEOT();
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_DSTAR);
-            } else {
-              DEBUG2("Received invalid D-Star EOT", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_DMR_DATA1:
-            if (m_dmrEnable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_DMR) {
-                if (m_duplex)
-                  err = dmrTX.writeData1(m_buffer + 3U, m_len - 3U);
-              }
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_DMR);
-            } else {
-              DEBUG2("Received invalid DMR data", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_DMR_DATA2:
-            if (m_dmrEnable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_DMR) {
-                if (m_duplex)
-                  err = dmrTX.writeData2(m_buffer + 3U, m_len - 3U);
-                else
-                  err = dmrDMOTX.writeData(m_buffer + 3U, m_len - 3U);
-              }
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_DMR);
-            } else {
-              DEBUG2("Received invalid DMR data", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_DMR_START:
-            if (m_dmrEnable) {
-              err = 4U;
-              if (m_len == 4U) {
-                if (m_buffer[3U] == 0x01U && m_modemState == STATE_DMR) {
-                  if (!m_tx)
-                    dmrTX.setStart(true);
-                  err = 0U;
-                } else if (m_buffer[3U] == 0x00U && m_modemState == STATE_DMR) {
-                  if (m_tx)
-                    dmrTX.setStart(false);
-                  err = 0U;
-                }
-              }
-            }
-            if (err != 0U) {
-              DEBUG2("Received invalid DMR start", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_DMR_SHORTLC:
-            if (m_dmrEnable)
-              err = dmrTX.writeShortLC(m_buffer + 3U, m_len - 3U);
-            if (err != 0U) {
-              DEBUG2("Received invalid DMR Short LC", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_DMR_ABORT:
-            if (m_dmrEnable)
-              err = dmrTX.writeAbort(m_buffer + 3U, m_len - 3U);
-            if (err != 0U) {
-              DEBUG2("Received invalid DMR Abort", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_YSF_DATA:
-            if (m_ysfEnable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_YSF)
-                err = ysfTX.writeData(m_buffer + 3U, m_len - 3U);
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_YSF);
-            } else {
-              DEBUG2("Received invalid System Fusion data", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_P25_HDR:
-            if (m_p25Enable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_P25)
-                err = p25TX.writeData(m_buffer + 3U, m_len - 3U);
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_P25);
-            } else {
-              DEBUG2("Received invalid P25 header", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_P25_LDU:
-            if (m_p25Enable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_P25)
-                err = p25TX.writeData(m_buffer + 3U, m_len - 3U);
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_P25);
-            } else {
-              DEBUG2("Received invalid P25 LDU", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_NXDN_DATA:
-            if (m_nxdnEnable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_NXDN)
-                err = nxdnTX.writeData(m_buffer + 3U, m_len - 3U);
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_NXDN);
-            } else {
-              DEBUG2("Received invalid NXDN data", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_POCSAG_DATA:
-            if (m_pocsagEnable) {
-              if (m_modemState == STATE_IDLE || m_modemState == STATE_POCSAG)
-                err = pocsagTX.writeData(m_buffer + 3U, m_len - 3U);
-            }
-            if (err == 0U) {
-              if (m_modemState == STATE_IDLE)
-                setMode(STATE_POCSAG);
-            } else {
-              DEBUG2("Received invalid POCSAG data", err);
-              sendNAK(err);
-            }
-            break;
-
-          case MMDVM_TRANSPARENT:
-          case MMDVM_QSO_INFO:
-            // Do nothing on the MMDVM.
-            break;
-
-#if defined(SERIAL_REPEATER)
-          case MMDVM_SERIAL: {
-            for (uint8_t i = 3U; i < m_len; i++)
-              m_repeat.put(m_buffer[i]);
-            }
-            break;
-#endif
-
-          default:
-            // Handle this, send a NAK back
-            sendNAK(1U);
-            break;
-        }
-
-        m_ptr = 0U;
-        m_len = 0U;
-      }
+      if (m_ptr == m_len)
+        processMessage();
     }
   }
 
@@ -941,6 +653,308 @@ void CSerialPort::process()
 #endif
 }
 
+void CSerialPort::processMessage()
+{
+  uint8_t err = 2U;
+
+  switch (m_buffer[2U]) {
+    case MMDVM_GET_STATUS:
+      getStatus();
+      break;
+
+    case MMDVM_GET_VERSION:
+      getVersion();
+      break;
+
+    case MMDVM_SET_CONFIG:
+      err = setConfig(m_buffer + 3U, m_len - 3U);
+      if (err == 0U)
+        sendACK();
+      else
+        sendNAK(err);
+      break;
+
+    case MMDVM_SET_MODE:
+      err = setMode(m_buffer + 3U, m_len - 3U);
+      if (err == 0U)
+        sendACK();
+      else
+        sendNAK(err);
+      break;
+
+    case MMDVM_SET_FREQ:
+      sendACK();
+      break;
+
+    case MMDVM_FM_PARAMS1:
+      err = setFMParams1(m_buffer + 3U, m_len - 3U);
+      if (err == 0U) {
+        sendACK();
+      } else {
+        DEBUG2("Received invalid FM params 1", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_FM_PARAMS2:
+      err = setFMParams2(m_buffer + 3U, m_len - 3U);
+      if (err == 0U) {
+        sendACK();
+      } else {
+        DEBUG2("Received invalid FM params 2", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_FM_PARAMS3:
+      err = setFMParams3(m_buffer + 3U, m_len - 3U);
+      if (err == 0U) {
+        sendACK();
+      } else {
+        DEBUG2("Received invalid FM params 3", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_CAL_DATA:
+      if (m_modemState == STATE_DSTARCAL)
+        err = calDStarTX.write(m_buffer + 3U, m_len - 3U);
+      if (m_modemState == STATE_DMRCAL || m_modemState == STATE_LFCAL || m_modemState == STATE_DMRCAL1K || m_modemState == STATE_DMRDMO1K)
+        err = calDMR.write(m_buffer + 3U, m_len - 3U);
+      if (m_modemState == STATE_FMCAL10K || m_modemState == STATE_FMCAL12K || m_modemState == STATE_FMCAL15K || m_modemState == STATE_FMCAL20K || m_modemState == STATE_FMCAL25K || m_modemState == STATE_FMCAL30K)
+        err = calFM.write(m_buffer + 3U, m_len - 3U);
+      if (m_modemState == STATE_P25CAL1K)
+        err = calP25.write(m_buffer + 3U, m_len - 3U);
+      if (m_modemState == STATE_NXDNCAL1K)
+        err = calNXDN.write(m_buffer + 3U, m_len - 3U);
+      if (m_modemState == STATE_POCSAGCAL)
+        err = calPOCSAG.write(m_buffer + 3U, m_len - 3U);
+      if (err == 0U) {
+        sendACK();
+      } else {
+        DEBUG2("Received invalid calibration data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_SEND_CWID:
+      err = 5U;
+      if (m_modemState == STATE_IDLE)
+        err = cwIdTX.write(m_buffer + 3U, m_len - 3U);
+      if (err != 0U) {
+        DEBUG2("Invalid CW Id data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_DSTAR_HEADER:
+      if (m_dstarEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_DSTAR)
+          err = dstarTX.writeHeader(m_buffer + 3U, m_len - 3U);
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_DSTAR);
+      } else {
+        DEBUG2("Received invalid D-Star header", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_DSTAR_DATA:
+      if (m_dstarEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_DSTAR)
+          err = dstarTX.writeData(m_buffer + 3U, m_len - 3U);
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_DSTAR);
+      } else {
+        DEBUG2("Received invalid D-Star data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_DSTAR_EOT:
+      if (m_dstarEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_DSTAR)
+          err = dstarTX.writeEOT();
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_DSTAR);
+      } else {
+        DEBUG2("Received invalid D-Star EOT", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_DMR_DATA1:
+      if (m_dmrEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_DMR) {
+          if (m_duplex)
+            err = dmrTX.writeData1(m_buffer + 3U, m_len - 3U);
+        }
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_DMR);
+      } else {
+        DEBUG2("Received invalid DMR data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_DMR_DATA2:
+      if (m_dmrEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_DMR) {
+          if (m_duplex)
+            err = dmrTX.writeData2(m_buffer + 3U, m_len - 3U);
+          else
+            err = dmrDMOTX.writeData(m_buffer + 3U, m_len - 3U);
+        }
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_DMR);
+      } else {
+        DEBUG2("Received invalid DMR data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_DMR_START:
+      if (m_dmrEnable) {
+        err = 4U;
+        if (m_len == 4U) {
+          if (m_buffer[3U] == 0x01U && m_modemState == STATE_DMR) {
+            if (!m_tx)
+              dmrTX.setStart(true);
+            err = 0U;
+          } else if (m_buffer[3U] == 0x00U && m_modemState == STATE_DMR) {
+            if (m_tx)
+              dmrTX.setStart(false);
+            err = 0U;
+          }
+        }
+      }
+      if (err != 0U) {
+        DEBUG2("Received invalid DMR start", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_DMR_SHORTLC:
+      if (m_dmrEnable)
+        err = dmrTX.writeShortLC(m_buffer + 3U, m_len - 3U);
+      if (err != 0U) {
+        DEBUG2("Received invalid DMR Short LC", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_DMR_ABORT:
+      if (m_dmrEnable)
+        err = dmrTX.writeAbort(m_buffer + 3U, m_len - 3U);
+      if (err != 0U) {
+        DEBUG2("Received invalid DMR Abort", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_YSF_DATA:
+      if (m_ysfEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_YSF)
+          err = ysfTX.writeData(m_buffer + 3U, m_len - 3U);
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_YSF);
+      } else {
+        DEBUG2("Received invalid System Fusion data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_P25_HDR:
+      if (m_p25Enable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_P25)
+          err = p25TX.writeData(m_buffer + 3U, m_len - 3U);
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_P25);
+      } else {
+        DEBUG2("Received invalid P25 header", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_P25_LDU:
+      if (m_p25Enable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_P25)
+          err = p25TX.writeData(m_buffer + 3U, m_len - 3U);
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_P25);
+      } else {
+        DEBUG2("Received invalid P25 LDU", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_NXDN_DATA:
+      if (m_nxdnEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_NXDN)
+          err = nxdnTX.writeData(m_buffer + 3U, m_len - 3U);
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_NXDN);
+      } else {
+        DEBUG2("Received invalid NXDN data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_POCSAG_DATA:
+      if (m_pocsagEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_POCSAG)
+          err = pocsagTX.writeData(m_buffer + 3U, m_len - 3U);
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_POCSAG);
+      } else {
+        DEBUG2("Received invalid POCSAG data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_TRANSPARENT:
+    case MMDVM_QSO_INFO:
+      // Do nothing on the MMDVM.
+      break;
+
+#if defined(SERIAL_REPEATER)
+    case MMDVM_SERIAL: {
+      for (uint8_t i = 3U; i < m_len; i++)
+        m_repeat.put(m_buffer[i]);
+      }
+      break;
+#endif
+
+    default:
+      // Handle this, send a NAK back
+      sendNAK(1U);
+      break;
+  }
+
+  m_ptr = 0U;
+  m_len = 0U;
+}
+
 void CSerialPort::writeDStarHeader(const uint8_t* header, uint8_t length)
 {
   if (m_modemState != STATE_DSTAR && m_modemState != STATE_IDLE)
@@ -1203,7 +1217,7 @@ void CSerialPort::writeNXDNLost()
   writeInt(1U, reply, 3);
 }
 
-void CSerialPort::writeAX25Data(const uint8_t* data, uint8_t length)
+void CSerialPort::writeAX25Data(const uint8_t* data, uint16_t length)
 {
   if (m_modemState != STATE_FM && m_modemState != STATE_IDLE)
     return;
@@ -1211,19 +1225,28 @@ void CSerialPort::writeAX25Data(const uint8_t* data, uint8_t length)
   if (!m_ax25Enable)
     return;
 
-  uint8_t reply[300U];
+  uint8_t reply[512U];
 
   reply[0U] = MMDVM_FRAME_START;
-  reply[1U] = 0U;
-  reply[2U] = MMDVM_AX25_DATA;
 
-  uint8_t count = 3U;
-  for (uint8_t i = 0U; i < length; i++, count++)
-    reply[count] = data[i];
+  if (length > 252U) {
+    reply[1U] = 0U;
+    reply[2U] = (length + 4U) - 255U;
+    reply[3U] = MMDVM_AX25_DATA;
 
-  reply[1U] = count;
+    for (uint8_t i = 0U; i < length; i++)
+      reply[i + 4U] = data[i];
 
-  writeInt(1U, reply, count);
+    writeInt(1U, reply, length + 4U);
+  } else {
+    reply[1U] = length + 3U;
+    reply[2U] = MMDVM_AX25_DATA;
+
+    for (uint8_t i = 0U; i < length; i++)
+      reply[i + 3U] = data[i];
+
+    writeInt(1U, reply, length + 3U);
+  }
 }
 
 void CSerialPort::writeCalData(const uint8_t* data, uint8_t length)
diff --git a/SerialPort.h b/SerialPort.h
index e8b9d58..57b8f00 100644
--- a/SerialPort.h
+++ b/SerialPort.h
@@ -50,7 +50,7 @@ public:
   void writeNXDNData(const uint8_t* data, uint8_t length);
   void writeNXDNLost();
 
-  void writeAX25Data(const uint8_t* data, uint8_t length);
+  void writeAX25Data(const uint8_t* data, uint16_t length);
 
   void writeCalData(const uint8_t* data, uint8_t length);
   void writeRSSIData(const uint8_t* data, uint8_t length);
@@ -62,9 +62,9 @@ public:
   void writeDebug(const char* text, int16_t n1, int16_t n2, int16_t n3, int16_t n4);
 
 private:
-  uint8_t   m_buffer[256U];
-  uint8_t   m_ptr;
-  uint8_t   m_len;
+  uint8_t   m_buffer[512U];
+  uint16_t  m_ptr;
+  uint16_t  m_len;
   bool      m_debug;
   CSerialRB m_repeat;
 
@@ -72,12 +72,13 @@ private:
   void    sendNAK(uint8_t err);
   void    getStatus();
   void    getVersion();
-  uint8_t setConfig(const uint8_t* data, uint8_t length);
-  uint8_t setMode(const uint8_t* data, uint8_t length);
+  uint8_t setConfig(const uint8_t* data, uint16_t length);
+  uint8_t setMode(const uint8_t* data, uint16_t length);
   void    setMode(MMDVM_STATE modemState);
-  uint8_t setFMParams1(const uint8_t* data, uint8_t length);
-  uint8_t setFMParams2(const uint8_t* data, uint8_t length);
-  uint8_t setFMParams3(const uint8_t* data, uint8_t length);
+  uint8_t setFMParams1(const uint8_t* data, uint16_t length);
+  uint8_t setFMParams2(const uint8_t* data, uint16_t length);
+  uint8_t setFMParams3(const uint8_t* data, uint16_t length);
+  void    processMessage();
 
   // Hardware versions
   void    beginInt(uint8_t n, int speed);
diff --git a/YSFTX.cpp b/YSFTX.cpp
index 090445a..9ac0607 100644
--- a/YSFTX.cpp
+++ b/YSFTX.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2018 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2018,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -116,7 +116,7 @@ void CYSFTX::process()
   }
 }
 
-uint8_t CYSFTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CYSFTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != (YSF_FRAME_LENGTH_BYTES + 1U))
     return 4U;
diff --git a/YSFTX.h b/YSFTX.h
index 647767c..4793221 100644
--- a/YSFTX.h
+++ b/YSFTX.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -27,7 +27,7 @@ class CYSFTX {
 public:
   CYSFTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();