diff --git a/src/main/java/de/neemann/digital/data/DataPlotter.java b/src/main/java/de/neemann/digital/data/DataPlotter.java
index dcb9817b2..14304a49f 100644
--- a/src/main/java/de/neemann/digital/data/DataPlotter.java
+++ b/src/main/java/de/neemann/digital/data/DataPlotter.java
@@ -90,9 +90,12 @@ public class DataPlotter implements Drawable {
      *
      * @param dx the displacement
      */
-    public void move(int dx) {
+    public void move(int dx, int dy) {
         xOffset -= dx;
         manualScaling = dx >= 0 || xOffset < autoScaleOffset;
+        yOffset -= dy;
+        if (yOffset < 0)
+            yOffset = 0;
     }
 
     @Override
diff --git a/src/main/java/de/neemann/digital/gui/components/data/GraphComponent.java b/src/main/java/de/neemann/digital/gui/components/data/GraphComponent.java
index f973baf17..053a99bb5 100644
--- a/src/main/java/de/neemann/digital/gui/components/data/GraphComponent.java
+++ b/src/main/java/de/neemann/digital/gui/components/data/GraphComponent.java
@@ -38,18 +38,22 @@ public class GraphComponent extends JComponent {
         });
 
         addMouseMotionListener(new MouseAdapter() {
-            private int lastPos;
+            private int lastxPos;
+            private int lastyPos;
 
             @Override
             public void mouseMoved(MouseEvent mouseEvent) {
-                lastPos = mouseEvent.getX();
+                lastxPos = mouseEvent.getX();
+                lastyPos = mouseEvent.getY();
             }
 
             @Override
             public void mouseDragged(MouseEvent mouseEvent) {
-                int pos = mouseEvent.getX();
-                plotter.move(pos - lastPos);
-                lastPos = pos;
+                int xPos = mouseEvent.getX();
+                int yPos = mouseEvent.getY();
+                plotter.move(xPos - lastxPos, yPos - lastyPos);
+                lastxPos = xPos;
+                lastyPos = yPos;
                 repaint();
             }