diff --git a/src/ExtendedSerial.h b/src/ExtendedSerial.h
index d3432ef..d971131 100644
--- a/src/ExtendedSerial.h
+++ b/src/ExtendedSerial.h
@@ -82,8 +82,12 @@ class ExtendedSerial : public Stream
                     ExtendedSerial(HardwareSerial& s) : _s(s) {}
 
     // Methods delegated to existing Serial instance
+#ifdef AVR
     void            begin(unsigned long baud)         { begin(baud, SERIAL_8N1);  }
     void            begin(unsigned long b, uint8_t m) { _s.begin(b,m);            }
+#else
+    void            begin(unsigned long baud)         { _s.begin(baud);           }
+#endif
     void            end()                             { _s.end();                 }
     virtual int     available(void)                   { return _s.available();    }
     virtual int     peek(void)                        { return _s.peek();         }
@@ -95,7 +99,9 @@ class ExtendedSerial : public Stream
     inline  size_t  write(long n)                     { return write((uint8_t)n); }
     inline  size_t  write(unsigned int n)             { return write((uint8_t)n); }
     inline  size_t  write(int n)                      { return write((uint8_t)n); }
+#ifdef AVR
     virtual int     availableForWrite(void)           { return _s.availableForWrite(); }
+#endif
     operator bool()                                   { return true;                   }
 
     // Extra methods
@@ -142,16 +148,15 @@ class ExtendedSerial : public Stream
     using           Print::print;   // pull in existing print methods from Print.
     using           Print::println; // pull in existing println methods from Print.
 
-  protected:
-                    // Must be instantiated with a HardwareSerial&.
-                    ExtendedSerial()                {}
-                    ExtendedSerial(ExtendedSerial&) {}
-                    ExtendedSerial(int)             {}
-                    ExtendedSerial(const char*)     {}
-
   private:
 
     HardwareSerial& _s;
+
+                    // Must be instantiated with a HardwareSerial&.
+                    ExtendedSerial();
+                    ExtendedSerial(ExtendedSerial&);
+                    ExtendedSerial(int);
+                    ExtendedSerial(const char*);
 };
 
 
diff --git a/src/Map2D3D.h b/src/Map2D3D.h
index b479383..536783c 100644
--- a/src/Map2D3D.h
+++ b/src/Map2D3D.h
@@ -79,6 +79,8 @@
 
 #ifdef AVR
 #include <avr/eeprom.h>
+#else
+#include <EEPROM.h>
 #endif
 
 
@@ -107,8 +109,10 @@ class Map
   public:
     virtual int   memSize() const                               =0;
 
+#ifdef AVR
     virtual bool  updateEeprom(uint8_t*      dest) const        =0;
     virtual bool  readEeprom( const uint8_t* src)               =0;
+#endif
 
     virtual void  printTo( Print& p, const uint8_t tabsize = 4,
                            const char delim = ' '              )=0;
@@ -173,7 +177,6 @@ class Map2D : public Map
     float         getYFloat( int i )    { return 0<=i<S ? static_cast<float>(ys[i]) : 0; }
 
 #ifdef AVR
-
     virtual bool  updateEeprom(uint8_t* dest) const
                   {
                     if( !eeprom_is_ready() ) return false;
@@ -360,6 +363,7 @@ class Map3D : public Map
     float         getYFloat( int i, int j )
                       { return 0<=i<R && 0<=j<C ? static_cast<float>(ys[i][j]) : 0; }
 
+#ifdef AVR
     virtual bool  updateEeprom(uint8_t* dest) const
                   {
                     if( !eeprom_is_ready() ) return false;
@@ -381,7 +385,7 @@ class Map3D : public Map
 
                     return true;
                   }
-
+#endif
 #ifdef ARDUINO    // Initialize from array in PROGMEM
 
     void          setX1s_P( const X* x1ss ) { memcpy_P( x1s, x1ss, R*sizeof(X) ); }