diff --git a/src/main/java/de/neemann/digital/core/SpeedTest.java b/src/main/java/de/neemann/digital/core/SpeedTest.java
index e15dd2356..e03f0eb58 100644
--- a/src/main/java/de/neemann/digital/core/SpeedTest.java
+++ b/src/main/java/de/neemann/digital/core/SpeedTest.java
@@ -24,7 +24,8 @@ public class SpeedTest {
 
 
         Clock clock = clocks.get(0);
-        model.init(true);
+        clock.disableTimer();
+        model.init();
         ObservableValue clockValue = clock.getOutputs()[0];
         int state = (int) clockValue.getValue();
 
diff --git a/src/main/java/de/neemann/digital/core/wiring/Clock.java b/src/main/java/de/neemann/digital/core/wiring/Clock.java
index 377e78e4b..6f3d0b5a8 100644
--- a/src/main/java/de/neemann/digital/core/wiring/Clock.java
+++ b/src/main/java/de/neemann/digital/core/wiring/Clock.java
@@ -20,6 +20,7 @@ public class Clock implements Element {
 
     private final ObservableValue output;
     private final int frequency;
+    public boolean startThisTimer = true;
 
     public Clock(ElementAttributes attributes) {
         output = new ObservableValue("C", 1);
@@ -36,10 +37,13 @@ public class Clock implements Element {
         return new ObservableValue[]{output};
     }
 
+    public void disableTimer() {
+        this.startThisTimer = false;
+    }
+
     @Override
     public void registerNodes(Model model) {
         model.addObserver(new ModelStateObserver() {
-            public boolean startThisTimer = true;
             public Timer timer;
 
             @Override
@@ -67,7 +71,7 @@ public class Clock implements Element {
                         break;
                     case FETCHCLOCK:
                         event.registerClock(Clock.this);
-                        startThisTimer = false;
+                        break;
                 }
             }
         });
diff --git a/src/main/java/de/neemann/digital/gui/InsertHistory.java b/src/main/java/de/neemann/digital/gui/InsertHistory.java
index 1bc7941f2..9d216dc7f 100644
--- a/src/main/java/de/neemann/digital/gui/InsertHistory.java
+++ b/src/main/java/de/neemann/digital/gui/InsertHistory.java
@@ -1,6 +1,7 @@
 package de.neemann.digital.gui;
 
 import javax.swing.*;
+import java.awt.event.ActionEvent;
 import java.util.ArrayList;
 
 /**
@@ -8,24 +9,69 @@ import java.util.ArrayList;
  */
 public class InsertHistory {
 
+    private static final int MAX_ICONS = 6;
     private final JToolBar bar;
-    private final ArrayList<AbstractAction> actions;
-    private final int removePos;
+    private final ArrayList<WrapperAction> wrappers;
+    private int mainTime;
 
     public InsertHistory(JToolBar bar) {
         this.bar = bar;
-        actions = new ArrayList<>();
-        removePos = bar.getComponentCount();
+        wrappers = new ArrayList<>();
     }
 
     public void add(AbstractAction action) {
-        if (!actions.contains(action)) {
-            actions.add(action);
-            bar.add(action);
-            if (actions.size() > 3) {
-                actions.remove(0);
-                bar.remove(removePos);
+        if (!contains(action)) {
+            WrapperAction wrapper = new WrapperAction(action, bar.getComponentCount());
+            wrappers.add(wrapper);
+            bar.add(wrapper);
+            if (wrappers.size() > MAX_ICONS) {
+                int oldest = findOldestIndex();
+                wrapper = wrappers.get(oldest);
+                bar.remove(wrapper.componentPosition);
+                for (int i = oldest; i < wrappers.size(); i++)
+                    wrappers.get(i).componentPosition--;
+                wrappers.remove(oldest);
             }
         }
     }
+
+    private int findOldestIndex() {
+        int found = -1;
+        int oldestTime = mainTime;
+        for (int i = 0; i < wrappers.size(); i++) {
+            WrapperAction wrapper = wrappers.get(i);
+            if (wrapper.time < oldestTime) {
+                found = i;
+                oldestTime = wrapper.time;
+            }
+        }
+        return found;
+    }
+
+    private boolean contains(AbstractAction action) {
+        for (WrapperAction wrapper : wrappers)
+            if (wrapper.action == action)
+                return true;
+        return false;
+    }
+
+    public class WrapperAction extends AbstractAction {
+
+        private final AbstractAction action;
+        private int componentPosition;
+        private int time;
+
+        public WrapperAction(AbstractAction action, int componentPosition) {
+            super(action.getValue(Action.NAME).toString(), (Icon) action.getValue(Action.SMALL_ICON));
+            this.action = action;
+            this.componentPosition = componentPosition;
+            time = mainTime++;
+        }
+
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            action.actionPerformed(e);
+            time = mainTime++;
+        }
+    }
 }
diff --git a/src/main/java/de/neemann/digital/gui/draw/shapes/LEDShape.java b/src/main/java/de/neemann/digital/gui/draw/shapes/LEDShape.java
index 08dc4bea6..181ccdc40 100644
--- a/src/main/java/de/neemann/digital/gui/draw/shapes/LEDShape.java
+++ b/src/main/java/de/neemann/digital/gui/draw/shapes/LEDShape.java
@@ -43,8 +43,9 @@ public class LEDShape implements Shape {
 
     @Override
     public void drawTo(Graphic graphic) {
-        boolean fill = false;
+        boolean fill = true;
         if (ioState != null) {
+            fill = false;
             ObservableValue value = ioState.getInput(0);
             if (!value.isHighZ() && (value.getValue() != 0))
                 fill = true;