diff --git a/src/main/java/de/neemann/digital/core/element/Key.java b/src/main/java/de/neemann/digital/core/element/Key.java
index ca3b74440..7d431ab66 100644
--- a/src/main/java/de/neemann/digital/core/element/Key.java
+++ b/src/main/java/de/neemann/digital/core/element/Key.java
@@ -132,8 +132,8 @@ public class Key<VALUE> {
     static final class KeyBits extends KeyInteger {
         private static final Integer[] VALUES = new Integer[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 32};
 
-        KeyBits(String key) {
-            super(key, 1);
+        KeyBits(String key, Integer def) {
+            super(key, def);
             setMin(1);
             setMax(64);
             setComboBoxValues(VALUES);
diff --git a/src/main/java/de/neemann/digital/core/element/Keys.java b/src/main/java/de/neemann/digital/core/element/Keys.java
index 2c9bb58ce..6748a1eb8 100644
--- a/src/main/java/de/neemann/digital/core/element/Keys.java
+++ b/src/main/java/de/neemann/digital/core/element/Keys.java
@@ -22,20 +22,22 @@ public final class Keys {
      * number of bits in simple gates like And and Or
      */
     public static final Key.KeyBits BITS
-            = new Key.KeyBits("Bits");
+            = new Key.KeyBits("Bits", 1);
 
     /**
      * number of inputs in simple gates like And and Or
      */
-    public static final Key.KeyInteger INPUT_COUNT
+    public static final Key.KeyInteger INPUT_COUNT  //  // needs to have the same default value as ADDR_BITS!!!  see de.neemann.digital.gui.components.EditorFactory#DataFieldEditor
             = new Key.KeyInteger("Inputs", 2)
             .setComboBoxValues(new Integer[]{2, 3, 4, 5})
             .setMin(2);
+
     /**
      * The elements label
      */
     public static final Key<String> LABEL
             = new Key<>("Label", "");
+
     /**
      * The size of a LED
      */
@@ -43,6 +45,7 @@ public final class Keys {
             = new Key.KeyInteger("Size", 1)
             .setComboBoxValues(new Integer[]{1, 2, 3, 4, 5})
             .setMin(1);
+
     /**
      * The value of constants
      */
@@ -86,16 +89,18 @@ public final class Keys {
             = new Key.KeyInteger("Frequency", 1)
             .setComboBoxValues(new Integer[]{1, 2, 5, 10, 20, 50, 100, 200, 500, 5000, 50000, 500000})
             .setMin(1);
+
     /**
      * the bit count of a muxer or decoder
      */
     public static final Key.KeyBits SELECTOR_BITS
-            = new Key.KeyBits("Selector Bits");
+            = new Key.KeyBits("Selector Bits", 1);
+
     /**
      * number of address bits of memory
      */
     public static final Key.KeyBits ADDR_BITS
-            = new Key.KeyBits("Addr Bits");
+            = new Key.KeyBits("Addr Bits", 2); // needs to have the same default value as INPUT_COUNT!!!  see de.neemann.digital.gui.components.EditorFactory#DataFieldEditor
 
     /**
      * indicates a diode as blown fuse or as programmed
@@ -120,11 +125,13 @@ public final class Keys {
      */
     public static final Key<DataField> DATA
             = new Key<>("Data", DataField.DEFAULT);
+
     /**
      * flag for flipping selector pos in muxers, decoders and drivers
      */
     public static final Key<Boolean> FLIP_SEL_POSITON
             = new Key<>("flipSelPos", false);
+
     /**
      * the rotation of the elements
      */
@@ -158,6 +165,7 @@ public final class Keys {
     public static final Key.KeyInteger CYCLES
             = new Key.KeyInteger("Cycles", 100000)
             .setComboBoxValues(new Integer[]{1000, 10000, 100000, 1000000});
+
     /**
      * flag to make a value a probe
      */
@@ -181,6 +189,7 @@ public final class Keys {
      */
     public static final Key<Boolean> SHOW_DATA_TABLE
             = new Key<>("showDataTable", false);
+
     /**
      * flag to show the data graph window
      */
@@ -205,6 +214,7 @@ public final class Keys {
     public static final Key.KeyInteger MAX_STEP_COUNT
             = new Key.KeyInteger("maxStepCount", 25)
             .setMin(5);
+
     /**
      * flag to enable high z mode at an input
      */
@@ -240,20 +250,19 @@ public final class Keys {
      */
     public static final Key<Language> SETTINGS_LANGUAGE
             = new Key<>("Language", new Language());
+
     /**
      * The GUI expression string representation
      */
     public static final Key<FormatToExpression> SETTINGS_EXPRESSION_FORMAT
             = new Key<>("ExpressionFormat", FormatToExpression.FORMATTER_UNICODE);
 
-
     /**
      * output format for numbers
      */
     public static final Key.KeyEnum<IntFormat> INTFORMAT
             = new Key.KeyEnum<>("intFormat", IntFormat.def, IntFormat.values());
 
-
     /**
      * width of the terminal
      */
diff --git a/src/main/java/de/neemann/digital/gui/components/EditorFactory.java b/src/main/java/de/neemann/digital/gui/components/EditorFactory.java
index ed10d002c..cba5df9c9 100644
--- a/src/main/java/de/neemann/digital/gui/components/EditorFactory.java
+++ b/src/main/java/de/neemann/digital/gui/components/EditorFactory.java
@@ -267,6 +267,10 @@ public final class EditorFactory {
                 public void actionPerformed(ActionEvent e) {
                     int bits = attr.get(Keys.BITS);
                     int size;
+
+                    // INPUT_COUNT and ADDR_BITS must have the same input value!!!
+                    // If INPUT_COUNT is not present (default value is used) the default value of
+                    // ADDR_BITS is used. This works only if both have the same default value!!!
                     if (attr.contains(Keys.INPUT_COUNT)) {
                         // used to handle the LUT
                         size = 1 << attr.get(Keys.INPUT_COUNT);