diff --git a/distribution/ReleaseNotes.txt b/distribution/ReleaseNotes.txt
index b937638ba..453093fdd 100644
--- a/distribution/ReleaseNotes.txt
+++ b/distribution/ReleaseNotes.txt
@@ -3,8 +3,9 @@ Release Notes
 HEAD, planned as v0.19
 - Added support for asynchronous sequential circuits such as the Muller-pipeline.
   Take a look at the new asynchronous examples for illustration.
-- Braking changes:
+- Breaking changes:
   - Added an enable input to the terminal component.
+  - Added a clock input to the keyboard component.
 - Bug fixes
   - Fixed a bug in the VHDL export concerning an invalid optimization of a
     std_logic_vector access.
diff --git a/src/main/java/de/neemann/digital/gui/Main.java b/src/main/java/de/neemann/digital/gui/Main.java
index 6304afd38..74d0037d0 100644
--- a/src/main/java/de/neemann/digital/gui/Main.java
+++ b/src/main/java/de/neemann/digital/gui/Main.java
@@ -35,6 +35,8 @@ import de.neemann.digital.gui.components.modification.Modifications;
 import de.neemann.digital.gui.components.modification.ModifyAttribute;
 import de.neemann.digital.gui.components.modification.ModifyMeasurementOrdering;
 import de.neemann.digital.gui.components.table.TableDialog;
+import de.neemann.digital.gui.components.terminal.Keyboard;
+import de.neemann.digital.gui.components.terminal.KeyboardDialog;
 import de.neemann.digital.gui.components.testing.ValueTableDialog;
 import de.neemann.digital.gui.components.tree.LibraryTreeModel;
 import de.neemann.digital.gui.components.tree.SelectTree;
@@ -1221,6 +1223,8 @@ public final class Main extends JFrame implements ClosingWindowListener.ConfirmS
                 // all repainting is initiated by user actions!
                 modelCreator.connectToGui(null);
 
+            handleKeyboardComponent(updateEvent, modelSync);
+
             doStep.setEnabled(false);
             runToBreakAction.setEnabled(!realTimeClockRunning && model.isFastRunModel());
 
@@ -1250,6 +1254,37 @@ public final class Main extends JFrame implements ClosingWindowListener.ConfirmS
         return false;
     }
 
+    private void handleKeyboardComponent(ModelEvent updateEvent, Sync modelSync) {
+        KeyboardDialog.KeyPressedHandler handler = null;
+        for (Keyboard k : model.findNode(Keyboard.class)) {
+            if (handler == null)
+                if (updateEvent == ModelEvent.MICROSTEP)
+                    handler = keyboard -> {
+                        keyboard.hasChanged();
+                        modelCreator.addNodeElementsTo(model.nodesToUpdate(), circuitComponent.getHighLighted());
+                        model.fireManualChangeEvent();
+                        doStep.setEnabled(model.needsUpdate());
+                        circuitComponent.repaintNeeded();
+                    };
+                else
+                    handler = keyboard -> {
+                        try {
+                            modelSync.accessNEx(() -> {
+                                keyboard.hasChanged();
+                                model.fireManualChangeEvent();
+                                model.doStep();
+                            });
+                            circuitComponent.repaintNeeded();
+                        } catch (NodeException | RuntimeException e) {
+                            showErrorAndStopModel(Lang.get("msg_errorCalculatingStep"), e);
+                        }
+                    };
+
+
+            windowPosManager.register("keyboard_" + k.getLabel(), new KeyboardDialog(this, k, handler));
+        }
+    }
+
     private void showMeasurementGraph(ModelEvent updateEvent) {
         List<String> ordering = circuitComponent.getCircuit().getMeasurementOrdering();
         windowPosManager.register("dataSet", GraphDialog.createLiveDialog(this, model, updateEvent == ModelEvent.MICROSTEP, ordering, modelSync)).setVisible(true);
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 ae3bd617e..5e033285e 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
@@ -14,8 +14,6 @@ import de.neemann.digital.core.element.ElementAttributes;
 import de.neemann.digital.core.element.ElementTypeDescription;
 import de.neemann.digital.core.element.Keys;
 
-import javax.swing.*;
-
 import static de.neemann.digital.core.element.PinInfo.input;
 
 /**
@@ -27,17 +25,20 @@ public class Keyboard extends Node implements Element {
      */
     public static final ElementTypeDescription DESCRIPTION
             = new ElementTypeDescription(Keyboard.class,
-            input("sel"))
+            input("C").setClock(),
+            input("en"))
             .addAttribute(Keys.ROTATE)
-            .addAttribute(Keys.LABEL);
+            .addAttribute(Keys.LABEL)
+            .addAttribute(Keys.INVERTER_CONFIG);
 
     private final String label;
-    private KeyboardDialog keyboardDialog;
-    private ObservableValue data;
-    private ObservableValue select;
-    private boolean sel;
-    private boolean lastSel = false;
-    private int keyData;
+    private final ObservableValue data;
+    private final ObservableValue isKeyOut;
+    private KeyboardInterface keyboardInterface;
+    private ObservableValue clock;
+    private ObservableValue enable;
+    private boolean enableVal;
+    private boolean lastClock = false;
 
     /**
      * Creates a new terminal instance
@@ -48,49 +49,83 @@ public class Keyboard extends Node implements Element {
         data = new ObservableValue("D", 16)
                 .setToHighZ()
                 .setPinDescription(DESCRIPTION);
+        isKeyOut = new ObservableValue("av", 1)
+                .setPinDescription(DESCRIPTION);
         label = attributes.getCleanLabel();
     }
 
     @Override
     public void setInputs(ObservableValues inputs) throws NodeException {
-        select = inputs.get(0).addObserverToValue(this).checkBits(1, this);
+        clock = inputs.get(0).addObserverToValue(this).checkBits(1, this, 0);
+        enable = inputs.get(1).addObserverToValue(this).checkBits(1, this, 1);
     }
 
     @Override
     public ObservableValues getOutputs() {
-        return data.asList();
+        return new ObservableValues(data, isKeyOut);
     }
 
     @Override
     public void readInputs() throws NodeException {
-        sel = select.getBool();
-        if (!lastSel && sel) {
-            KeyboardDialog kbd = getKeyboard();
-            if (kbd != null)
-                keyData = kbd.getChar();
-            else
-                keyData = 0;
-        }
-        lastSel = sel;
+        enableVal = enable.getBool();
+        boolean nowClock = clock.getBool();
+
+        if (keyboardInterface != null && nowClock && !lastClock && enableVal)
+            keyboardInterface.removeChar();
+
+        lastClock = nowClock;
     }
 
     @Override
     public void writeOutputs() throws NodeException {
-        if (sel)
-            data.setValue(keyData);
-        else
-            data.setToHighZ();
+        if (keyboardInterface != null) {
+            if (enableVal)
+                data.setValue(keyboardInterface.getChar());
+            else
+                data.setToHighZ();
+            isKeyOut.setBool(keyboardInterface.isChar());
+        } else {
+            if (enableVal)
+                data.setValue(0);
+            else
+                data.setToHighZ();
+            isKeyOut.setBool(false);
+        }
     }
 
-    private KeyboardDialog getKeyboard() {
-        if (keyboardDialog == null || !keyboardDialog.isVisible()) {
-            SwingUtilities.invokeLater(() -> {
-                if (keyboardDialog == null || !keyboardDialog.isVisible()) {
-                    keyboardDialog = new KeyboardDialog(getModel().getWindowPosManager().getMainFrame());
-                    getModel().getWindowPosManager().register("keyboard_" + label, keyboardDialog);
-                }
-            });
-        }
-        return keyboardDialog;
+    /**
+     * Sets the keyboard interface
+     *
+     * @param keyboardInterface the keyboard interface
+     */
+    public void setKeyboardDialog(KeyboardInterface keyboardInterface) {
+        this.keyboardInterface = keyboardInterface;
+    }
+
+    /**
+     * @return the keyboard label
+     */
+    public String getLabel() {
+        return label;
+    }
+
+    /**
+     * The keyboard interface
+     */
+    public interface KeyboardInterface {
+        /**
+         * @return a char or 0 if no char available
+         */
+        int getChar();
+
+        /**
+         * @return true if there is a char
+         */
+        boolean isChar();
+
+        /**
+         * removes the first character
+         */
+        void removeChar();
     }
 }
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 195dbfc25..b75675cee 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
@@ -15,7 +15,7 @@ import java.awt.event.KeyEvent;
 /**
  * A simple keyboard implementation
  */
-public class KeyboardDialog extends JDialog {
+public class KeyboardDialog extends JDialog implements Keyboard.KeyboardInterface {
     private final JLabel textLabel;
     private final Object textLock = new Object();
     private String text;
@@ -23,13 +23,15 @@ public class KeyboardDialog extends JDialog {
     /**
      * Create a new Instance
      *
-     * @param owner the owner frame
+     * @param owner             the owner frame
+     * @param keyboard          the keyboard node which has opened this dialog
+     * @param keyPressedHandler handler called every time a key is typed
      */
-    public KeyboardDialog(Frame owner) {
-        super(owner, Lang.get("elem_Keyboard"), false);
+    public KeyboardDialog(Frame owner, Keyboard keyboard, KeyPressedHandler keyPressedHandler) {
+        super(owner, Lang.get("elem_Keyboard") + " " + keyboard.getLabel(), false);
         setDefaultCloseOperation(DISPOSE_ON_CLOSE);
 
-        textLabel = new JLabel("Enter Text       ");
+        textLabel = new JLabel(Lang.get("msg_enterText") + "          ");
         textLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
         getContentPane().add(textLabel);
         text = "";
@@ -43,6 +45,7 @@ public class KeyboardDialog extends JDialog {
                     text += e.getKeyChar();
                     t = text;
                 }
+                keyPressedHandler.keyPressed(keyboard);
                 textLabel.setText(t);
             }
         });
@@ -50,24 +53,47 @@ public class KeyboardDialog extends JDialog {
         pack();
         setLocationRelativeTo(owner);
         setVisible(true);
+
+        keyboard.setKeyboardDialog(this);
     }
 
-    /**
-     * @return the oldest char
-     */
+    @Override
     public int getChar() {
         synchronized (textLock) {
             if (text.length() == 0)
                 return 0;
-            else {
-                int c = text.charAt(0);
-                String t;
+            else
+                return text.charAt(0);
+        }
+    }
+
+    @Override
+    public boolean isChar() {
+        synchronized (textLock) {
+            return text.length() > 0;
+        }
+    }
+
+    @Override
+    public void removeChar() {
+        synchronized (textLock) {
+            if (text.length() > 0) {
                 text = text.substring(1);
-                t = text;
+                final String t = text;
                 SwingUtilities.invokeLater(() -> textLabel.setText(t));
-                return c;
             }
         }
     }
 
+    /**
+     * The handler called if a key is typed.
+     */
+    public interface KeyPressedHandler {
+        /**
+         * Called if a key is typed
+         *
+         * @param keyboard the keyboard used
+         */
+        void keyPressed(Keyboard keyboard);
+    }
 }
diff --git a/src/main/resources/lang/lang_de.xml b/src/main/resources/lang/lang_de.xml
index 391eadefc..71cb0bc8d 100644
--- a/src/main/resources/lang/lang_de.xml
+++ b/src/main/resources/lang/lang_de.xml
@@ -224,8 +224,13 @@
         Dieses Element puffert die Eingaben, welche dann ausgelesen werden können.
         Es wird ein eigenes Fenster für die Eingabe geöffnet.
     </string>
-    <string name="elem_Keyboard_pin_sel">Wenn gesetzt, ist der Ausgang D aktiv und ein Tastendruck wird ausgegeben.</string>
+    <string name="elem_Keyboard_pin_C">Takt. Eine steigende Flanke entfernt das älteste Zeichen aus dem Buffer.</string>
+    <string name="elem_Keyboard_pin_en">Wenn gesetzt, ist der Ausgang D aktiv und ein Tastendruck wird ausgegeben.
+        Ist gleichzeitig die freigabe für den Takt.</string>
     <string name="elem_Keyboard_pin_D">Die letzte Taste oder 0, wenn keine Taste gedrückt.</string>
+    <string name="elem_Keyboard_pin_av">Dieser Ausgang zeigt an, dass Zeichen vorhanden sind.
+        Er kann genutzt werden, um einen Interrupt auszulösen.</string>
+
     <string name="elem_Terminal">Terminal</string>
     <string name="elem_Terminal_tt">Ein Terminal, auf dem ASCII-Zeichen ausgegeben werden können.
         Öffnet ein eigenes Fenster, um die Ausgabe anzuzeigen.</string>
@@ -1429,6 +1434,7 @@ Soll dennoch exportiert werden?</string>
         nicht der Fall ist, wird die Fehlermeldung der externen Anwendung angezeigt. Wenn es möglich ist, werden zudem
         die Eingangs- und Ausgangsdefinitionen an den aktuellen Code angepasst.</string>
     <string name="msg_applicationFileNotFound">Ausführbare Datei "{0}" nicht gefunden!</string>
+    <string name="msg_enterText">Text eingeben!</string>
 
     <string name="ok">Ok</string>
     <string name="rot_0">0°</string>
diff --git a/src/main/resources/lang/lang_en.xml b/src/main/resources/lang/lang_en.xml
index ea4f387f8..092e3440a 100644
--- a/src/main/resources/lang/lang_en.xml
+++ b/src/main/resources/lang/lang_en.xml
@@ -223,13 +223,19 @@
     <string name="elem_RotEncoder_tt">Rotary knob with rotary encoder. Used to detect rotational movements.</string>
     <string name="elem_RotEncoder_pin_A">encoder signal A</string>
     <string name="elem_RotEncoder_pin_B">encoder signal B</string>
+
     <string name="elem_Keyboard">Keyboard</string>
     <string name="elem_Keyboard_tt">A keyboard that can be used to enter text.
-        This component buffers the inputs, which can then be read out.
+        This component buffers the input, which can then be read out.
         A separate window is opened for the text input.
     </string>
-    <string name="elem_Keyboard_pin_sel">If high the output D is active and one keystroke is output.</string>
-    <string name="elem_Keyboard_pin_D">The last pressed key, or zero if no key is typed.</string>
+    <string name="elem_Keyboard_pin_C">Clock. A rising edge removes the oldest character from the buffer.</string>
+    <string name="elem_Keyboard_pin_en">If high the output D is active and one character is output.
+        It also enables the clock input.</string>
+    <string name="elem_Keyboard_pin_D">The last typed character, or zero if no character is available.</string>
+    <string name="elem_Keyboard_pin_av">This output indicates that characters are available.
+        It can be used to trigger an interrupt.</string>
+
     <string name="elem_Terminal">Terminal</string>
     <string name="elem_Terminal_tt">You can write ASCII characters to this terminal.
         The terminal opens its own window to visualize the output.</string>
@@ -1417,6 +1423,7 @@
         If this is not the case, the error message of the external application is displayed.
         If possible, the input and output definitions are also adapted to the current code.</string>
     <string name="msg_applicationFileNotFound">Executable file "{0}" not found!</string>
+    <string name="msg_enterText">Enter Text!</string>
 
     <string name="ok">Ok</string>
     <string name="rot_0">0°</string>
diff --git a/src/test/resources/dig/backtrack/AllComponents.dig b/src/test/resources/dig/backtrack/AllComponents.dig
index 40393f6e4..18ae86ac0 100644
--- a/src/test/resources/dig/backtrack/AllComponents.dig
+++ b/src/test/resources/dig/backtrack/AllComponents.dig
@@ -170,7 +170,7 @@
     <visualElement>
       <elementName>Terminal</elementName>
       <elementAttributes/>
-      <pos x="420" y="900"/>
+      <pos x="420" y="920"/>
     </visualElement>
     <visualElement>
       <elementName>VDD</elementName>
@@ -575,6 +575,10 @@
       <p1 x="780" y="640"/>
       <p2 x="800" y="640"/>
     </wire>
+    <wire>
+      <p1 x="400" y="960"/>
+      <p2 x="420" y="960"/>
+    </wire>
     <wire>
       <p1 x="240" y="260"/>
       <p2 x="260" y="260"/>
@@ -619,10 +623,6 @@
       <p1 x="460" y="580"/>
       <p2 x="480" y="580"/>
     </wire>
-    <wire>
-      <p1 x="380" y="900"/>
-      <p2 x="420" y="900"/>
-    </wire>
     <wire>
       <p1 x="780" y="200"/>
       <p2 x="800" y="200"/>
@@ -776,7 +776,7 @@
       <p2 x="1160" y="660"/>
     </wire>
     <wire>
-      <p1 x="400" y="920"/>
+      <p1 x="380" y="920"/>
       <p2 x="420" y="920"/>
     </wire>
     <wire>
@@ -923,6 +923,10 @@
       <p1 x="580" y="680"/>
       <p2 x="640" y="680"/>
     </wire>
+    <wire>
+      <p1 x="400" y="940"/>
+      <p2 x="420" y="940"/>
+    </wire>
     <wire>
       <p1 x="780" y="620"/>
       <p2 x="800" y="620"/>
@@ -959,10 +963,6 @@
       <p1 x="660" y="300"/>
       <p2 x="680" y="300"/>
     </wire>
-    <wire>
-      <p1 x="400" y="940"/>
-      <p2 x="420" y="940"/>
-    </wire>
     <wire>
       <p1 x="580" y="560"/>
       <p2 x="620" y="560"/>
@@ -995,6 +995,10 @@
       <p1 x="760" y="880"/>
       <p2 x="880" y="880"/>
     </wire>
+    <wire>
+      <p1 x="400" y="880"/>
+      <p2 x="420" y="880"/>
+    </wire>
     <wire>
       <p1 x="600" y="500"/>
       <p2 x="620" y="500"/>
@@ -1276,8 +1280,8 @@
       <p2 x="400" y="580"/>
     </wire>
     <wire>
-      <p1 x="400" y="920"/>
-      <p2 x="400" y="940"/>
+      <p1 x="400" y="940"/>
+      <p2 x="400" y="960"/>
     </wire>
     <wire>
       <p1 x="400" y="580"/>
@@ -1305,12 +1309,16 @@
     </wire>
     <wire>
       <p1 x="400" y="860"/>
-      <p2 x="400" y="920"/>
+      <p2 x="400" y="880"/>
     </wire>
     <wire>
       <p1 x="400" y="360"/>
       <p2 x="400" y="400"/>
     </wire>
+    <wire>
+      <p1 x="400" y="880"/>
+      <p2 x="400" y="940"/>
+    </wire>
     <wire>
       <p1 x="600" y="100"/>
       <p2 x="600" y="220"/>
@@ -1653,7 +1661,7 @@
     </wire>
     <wire>
       <p1 x="380" y="820"/>
-      <p2 x="380" y="900"/>
+      <p2 x="380" y="920"/>
     </wire>
   </wires>
   <measurementOrdering/>