diff --git a/src/main/java/de/neemann/digital/core/memory/EEPROM.java b/src/main/java/de/neemann/digital/core/memory/EEPROM.java
index a784426df..5c571221d 100644
--- a/src/main/java/de/neemann/digital/core/memory/EEPROM.java
+++ b/src/main/java/de/neemann/digital/core/memory/EEPROM.java
@@ -1,10 +1,5 @@
 package de.neemann.digital.core.memory;
 
-import de.neemann.digital.core.Node;
-import de.neemann.digital.core.NodeException;
-import de.neemann.digital.core.ObservableValue;
-import de.neemann.digital.core.ObservableValues;
-import de.neemann.digital.core.element.Element;
 import de.neemann.digital.core.element.ElementAttributes;
 import de.neemann.digital.core.element.ElementTypeDescription;
 import de.neemann.digital.core.element.Keys;
@@ -16,7 +11,7 @@ import static de.neemann.digital.core.element.PinInfo.input;
  *
  * @author hneemann
  */
-public class EEPROM extends Node implements Element {
+public class EEPROM extends RAMSinglePortSel {
 
     /**
      * The EEPROMs {@link ElementTypeDescription}
@@ -32,73 +27,22 @@ public class EEPROM extends Node implements Element {
             .addAttribute(Keys.LABEL)
             .addAttribute(Keys.DATA);
 
-    private final int bits;
-    private final int addrBits;
-    private final DataField memory;
-    private final ObservableValue dataOut;
-
-    private ObservableValue addrIn;
-    private ObservableValue csIn;
-    private ObservableValue weIn;
-    private ObservableValue oeIn;
-    private ObservableValue dataIn;
-    private int addr;
-    private boolean cs;
-    private boolean oe;
-
     /**
      * Creates a new instance
      *
      * @param attr the elements attributes
      */
     public EEPROM(ElementAttributes attr) {
-        super(true);
-        bits = attr.get(Keys.BITS);
-        addrBits = attr.get(Keys.ADDR_BITS);
-        int size = 1 << addrBits;
+        super(attr);
+    }
+
+    @Override
+    protected DataField createDataField(ElementAttributes attr, int size) {
         DataField memory = attr.get(Keys.DATA);
-        if (memory.size() < size) {
+        if (memory.size() != size) {
             memory = new DataField(memory, size);
             attr.set(Keys.DATA, memory);
         }
-        this.memory = memory;
-        dataOut = new ObservableValue("D", bits, true).setPinDescription(DESCRIPTION).setBidirectional();
+        return memory;
     }
-
-    @Override
-    public void setInputs(ObservableValues inputs) throws NodeException {
-        addrIn = inputs.get(0).checkBits(addrBits, this).addObserverToValue(this);
-        csIn = inputs.get(1).checkBits(1, this).addObserverToValue(this);
-        weIn = inputs.get(2).checkBits(1, this).addObserverToValue(this);
-        oeIn = inputs.get(3).checkBits(1, this).addObserverToValue(this);
-        dataIn = inputs.get(4).checkBits(bits, this).addObserverToValue(this);
-    }
-
-    @Override
-    public void readInputs() throws NodeException {
-        cs = csIn.getBool();
-        if (cs) {
-            addr = (int) addrIn.getValue();
-            oe = oeIn.getBool();
-            if (weIn.getBool()) {
-                long data = dataIn.getValue();
-                memory.setData(addr, data);
-            }
-        }
-    }
-
-    @Override
-    public void writeOutputs() throws NodeException {
-        if (cs && oe) {
-            dataOut.set(memory.getDataWord(addr), false);
-        } else {
-            dataOut.set(0, true);
-        }
-    }
-
-    @Override
-    public ObservableValues getOutputs() {
-        return dataOut.asList();
-    }
-
 }
diff --git a/src/main/java/de/neemann/digital/core/memory/RAMSinglePortSel.java b/src/main/java/de/neemann/digital/core/memory/RAMSinglePortSel.java
index 70baa0f73..7380967f8 100644
--- a/src/main/java/de/neemann/digital/core/memory/RAMSinglePortSel.java
+++ b/src/main/java/de/neemann/digital/core/memory/RAMSinglePortSel.java
@@ -60,11 +60,22 @@ public class RAMSinglePortSel extends Node implements Element, RAMInterface {
         bits = attr.get(Keys.BITS);
         addrBits = attr.get(Keys.ADDR_BITS);
         size = 1 << addrBits;
-        memory = new DataField(size);
+        memory = createDataField(attr, size);
         label = attr.getCleanLabel();
         dataOut = new ObservableValue("D", bits, true).setPinDescription(DESCRIPTION).setBidirectional();
     }
 
+    /**
+     * creates the data field to use
+     *
+     * @param attr the elements attributes
+     * @param size the size of the memory
+     * @return the memory to use
+     */
+    protected DataField createDataField(ElementAttributes attr, int size) {
+        return new DataField(size);
+    }
+
     @Override
     public void setInputs(ObservableValues inputs) throws NodeException {
         addrIn = inputs.get(0).checkBits(addrBits, this).addObserverToValue(this);