diff --git a/src/knx/memory.cpp b/src/knx/memory.cpp
index be96714..17ebc70 100644
--- a/src/knx/memory.cpp
+++ b/src/knx/memory.cpp
@@ -15,6 +15,8 @@ bool Memory::isMemoryModified()
     return _modified;
 }
 
+// TODO implement flash layout: manufacturerID, HarwareType, Version, addr[0], size[0], addr[1], size[1], ...
+// reconstruct free flash list and used list on read
 void Memory::readMemory()
 {
     _data = _platform.getEepromBuffer(512);
@@ -41,7 +43,9 @@ void Memory::writeMemory()
     int size = _saveCount;
     for (int i = 0; i < size; i++)
     {
-        buffer = _saveRestores[i]->save(buffer);
+        SaveRestore* saveRestore = dynamic_cast<SaveRestore*>(_saveRestores[i]);
+        if(saveRestore)
+            buffer = saveRestore->save(buffer);
     }
     _platform.commitToEeprom();
     _modified = false;
diff --git a/src/knx/memory.h b/src/knx/memory.h
index c299d22..505048a 100644
--- a/src/knx/memory.h
+++ b/src/knx/memory.h
@@ -25,7 +25,7 @@ public:
   private:
     Platform& _platform;
     bool _modified = false;
-    SaveRestore* _saveRestores[MAXSAVE] = {0};
+    Restore* _saveRestores[MAXSAVE] = {0};
     int _saveCount = 0;
     uint8_t* _data = 0;
 };
diff --git a/src/knx/restore.h b/src/knx/restore.h
new file mode 100644
index 0000000..fe8ca41
--- /dev/null
+++ b/src/knx/restore.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#pragma once
+#include <stdint.h>
+
+/**
+ * Interface for classes that can restore data from a buffer. 
+ */
+class Restore
+{
+  public:
+    /**
+     * This method is called when the object should restore its state from the buffer.
+     *  
+     * @param buffer The buffer the object should restore its state from.
+     * 
+     * @return The buffer plus the size of the object state. The next object will use this value as 
+     * the start of its buffer.
+     */
+    virtual uint8_t* restore(uint8_t* buffer) = 0;
+};
\ No newline at end of file
diff --git a/src/knx/save_restore.h b/src/knx/save_restore.h
index f87091d..d36d563 100644
--- a/src/knx/save_restore.h
+++ b/src/knx/save_restore.h
@@ -1,10 +1,11 @@
 #pragma once
 #include <stdint.h>
+#include "restore.h"
 
 /**
  * Interface for classes that can save and restore data from a buffer. 
  */
-class SaveRestore
+class SaveRestore : public Restore
 {
   public:
     /**
@@ -16,13 +17,4 @@ class SaveRestore
      * the start of its buffer.
      */
     virtual uint8_t* save(uint8_t* buffer) = 0;
-    /**
-     * This method is called when the object should restore its state from the buffer.
-     *  
-     * @param buffer The buffer the object should restore its state from.
-     * 
-     * @return The buffer plus the size of the object state. The next object will use this value as 
-     * the start of its buffer.
-     */
-    virtual uint8_t* restore(uint8_t* buffer) = 0;
 };
\ No newline at end of file