diff --git a/src/main/java/de/neemann/digital/gui/components/terminal/Keyboard.java b/src/main/java/de/neemann/digital/gui/components/terminal/Keyboard.java
index f10c3b388..06af43c79 100644
--- a/src/main/java/de/neemann/digital/gui/components/terminal/Keyboard.java
+++ b/src/main/java/de/neemann/digital/gui/components/terminal/Keyboard.java
@@ -17,6 +17,7 @@ import de.neemann.digital.core.element.Keys;
 import static de.neemann.digital.core.element.PinInfo.input;
 
 /**
+ * The Keyboard component
  */
 public class Keyboard extends Node implements Element {
 
@@ -33,13 +34,12 @@ public class Keyboard extends Node implements Element {
 
     private final String label;
     private final ObservableValue data;
-    private final ObservableValue isKeyOut;
+    private final ObservableValue keyAvail;
     private KeyboardInterface keyboardInterface;
     private ObservableValue clock;
     private ObservableValue enable;
     private boolean enableVal;
     private boolean lastClock = false;
-    private int nextChar;
 
     /**
      * Creates a new terminal instance
@@ -50,7 +50,7 @@ public class Keyboard extends Node implements Element {
         data = new ObservableValue("D", 16)
                 .setToHighZ()
                 .setPinDescription(DESCRIPTION);
-        isKeyOut = new ObservableValue("av", 1)
+        keyAvail = new ObservableValue("av", 1)
                 .setPinDescription(DESCRIPTION);
         label = attributes.getLabel();
     }
@@ -63,7 +63,7 @@ public class Keyboard extends Node implements Element {
 
     @Override
     public ObservableValues getOutputs() {
-        return new ObservableValues(data, isKeyOut);
+        return new ObservableValues(data, keyAvail);
     }
 
     @Override
@@ -71,8 +71,8 @@ public class Keyboard extends Node implements Element {
         enableVal = enable.getBool();
         boolean nowClock = clock.getBool();
 
-        if (keyboardInterface != null && nowClock && !lastClock && enableVal)
-            nextChar = keyboardInterface.getChar();
+        if (keyboardInterface != null && !nowClock && lastClock && enableVal)
+            keyboardInterface.deleteFirstChar();
 
         lastClock = nowClock;
     }
@@ -81,16 +81,16 @@ public class Keyboard extends Node implements Element {
     public void writeOutputs() throws NodeException {
         if (keyboardInterface != null) {
             if (enableVal)
-                data.setValue(nextChar);
+                data.setValue(keyboardInterface.getChar());
             else
                 data.setToHighZ();
-            isKeyOut.setBool(keyboardInterface.isChar() || nextChar != 0);
+            keyAvail.setBool(keyboardInterface.getChar() != 0);
         } else {
             if (enableVal)
                 data.setValue(0);
             else
                 data.setToHighZ();
-            isKeyOut.setBool(false);
+            keyAvail.setBool(false);
         }
     }
 
@@ -115,14 +115,14 @@ public class Keyboard extends Node implements Element {
      */
     public interface KeyboardInterface {
         /**
-         * @return a char or 0 if no char available
+         * @return a char or 0 if no char available, does not remove the char
          */
         int getChar();
 
         /**
-         * @return true if there is a char
+         * removes the first char
          */
-        boolean isChar();
+        void deleteFirstChar();
 
     }
 }
diff --git a/src/main/java/de/neemann/digital/gui/components/terminal/KeyboardDialog.java b/src/main/java/de/neemann/digital/gui/components/terminal/KeyboardDialog.java
index d41fa8138..24ee3a793 100644
--- a/src/main/java/de/neemann/digital/gui/components/terminal/KeyboardDialog.java
+++ b/src/main/java/de/neemann/digital/gui/components/terminal/KeyboardDialog.java
@@ -64,19 +64,19 @@ public class KeyboardDialog extends JDialog implements Keyboard.KeyboardInterfac
             if (text.length() == 0)
                 return 0;
             else {
-                final char c = text.charAt(0);
-                text = text.substring(1);
-                final String t = text;
-                SwingUtilities.invokeLater(() -> textLabel.setText(t));
-                return c;
+                return text.charAt(0);
             }
         }
     }
 
     @Override
-    public boolean isChar() {
+    public void deleteFirstChar() {
         synchronized (textLock) {
-            return text.length() > 0;
+            if (text.length() > 0) {
+                text = text.substring(1);
+                final String t = text;
+                SwingUtilities.invokeLater(() -> textLabel.setText(t));
+            }
         }
     }