diff --git a/src/main/java/de/neemann/digital/core/Model.java b/src/main/java/de/neemann/digital/core/Model.java
index 713cf8896..05e8d4047 100644
--- a/src/main/java/de/neemann/digital/core/Model.java
+++ b/src/main/java/de/neemann/digital/core/Model.java
@@ -828,15 +828,6 @@ public class Model implements Iterable<Node>, SyncAccess {
         return run;
     }
 
-    @Override
-    public <A extends ModelRun> A modifyNEx(A run) throws NodeException {
-        synchronized (this) {
-            run.run();
-        }
-        fireEvent(ModelEvent.EXTERNALCHANGE);
-        return run;
-    }
-
     @Override
     public <A extends Runnable> A read(A run) {
         synchronized (this) {
diff --git a/src/main/java/de/neemann/digital/core/SyncAccess.java b/src/main/java/de/neemann/digital/core/SyncAccess.java
index dde025886..69e4896f3 100644
--- a/src/main/java/de/neemann/digital/core/SyncAccess.java
+++ b/src/main/java/de/neemann/digital/core/SyncAccess.java
@@ -33,12 +33,6 @@ public interface SyncAccess {
             return run;
         }
 
-        @Override
-        public <A extends ModelRun> A modifyNEx(A run) throws NodeException {
-            run.run();
-            return run;
-        }
-
         @Override
         public <A extends Runnable> A read(A run) {
             run.run();
@@ -56,17 +50,6 @@ public interface SyncAccess {
      */
     <A extends Runnable> A modify(A run);
 
-    /**
-     * Same as access, but catches an exception.
-     * The runnable is allowed to modify the model.
-     *
-     * @param run the runnable to execute
-     * @param <A> the type oth the runnable
-     * @return the given runnable. Used for chained calls
-     * @throws NodeException NodeException
-     */
-    <A extends SyncAccess.ModelRun> A modifyNEx(A run) throws NodeException;
-
     /**
      * Calls the given runnable
      * The runnable is NOT allowed to modify the model.
@@ -77,11 +60,4 @@ public interface SyncAccess {
      */
     <A extends Runnable> A read(A run);
 
-    /**
-     * Like runnable but throws an exception
-     */
-    interface ModelRun {
-        void run() throws NodeException;
-    }
-
 }
diff --git a/src/main/java/de/neemann/digital/draw/model/AsyncSequentialClock.java b/src/main/java/de/neemann/digital/draw/model/AsyncSequentialClock.java
index 4493cd50a..cbfa04497 100644
--- a/src/main/java/de/neemann/digital/draw/model/AsyncSequentialClock.java
+++ b/src/main/java/de/neemann/digital/draw/model/AsyncSequentialClock.java
@@ -77,7 +77,7 @@ public class AsyncSequentialClock implements ModelStateObserverTyped {
                 @Override
                 public void run() {
                     try {
-                        model.modifyNEx(() -> model.doMicroStep(false));
+                        model.doMicroStep(false);
                     } catch (NodeException | RuntimeException e) {
                         stopper.showErrorAndStopModel(Lang.get("msg_clockError"), e);
                         timer.cancel(false);