diff --git a/src/main/java/de/neemann/digital/core/Model.java b/src/main/java/de/neemann/digital/core/Model.java
index dcec6837f..5e4fe09b7 100644
--- a/src/main/java/de/neemann/digital/core/Model.java
+++ b/src/main/java/de/neemann/digital/core/Model.java
@@ -1,5 +1,6 @@
 package de.neemann.digital.core;
 
+import de.neemann.digital.core.memory.ROM;
 import de.neemann.digital.core.wiring.Break;
 import de.neemann.digital.core.wiring.Clock;
 import de.neemann.digital.core.wiring.Reset;
@@ -43,6 +44,7 @@ public class Model implements Iterable<Node> {
     private final ArrayList<Clock> clocks;
     private final ArrayList<Break> breaks;
     private final ArrayList<Reset> resets;
+    private final ArrayList<ROM> progRoms;
 
     private final ArrayList<Signal> signals;
     private final ArrayList<Signal> inputs;
@@ -62,6 +64,7 @@ public class Model implements Iterable<Node> {
         this.clocks = new ArrayList<>();
         this.breaks = new ArrayList<>();
         this.resets = new ArrayList<>();
+        this.progRoms = new ArrayList<>();
         this.signals = new ArrayList<>();
         this.outputs = new ArrayList<>();
         this.inputs = new ArrayList<>();
@@ -429,6 +432,15 @@ public class Model implements Iterable<Node> {
         return n;
     }
 
+
+    public void addProgRom(ROM rom) {
+        progRoms.add(rom);
+    }
+
+    public ArrayList<ROM> getProgRoms() {
+        return progRoms;
+    }
+
     /**
      * fires a model changed event to all listeners
      */
diff --git a/src/main/java/de/neemann/digital/core/memory/ROM.java b/src/main/java/de/neemann/digital/core/memory/ROM.java
index 9c8a786dc..4653726f5 100644
--- a/src/main/java/de/neemann/digital/core/memory/ROM.java
+++ b/src/main/java/de/neemann/digital/core/memory/ROM.java
@@ -115,6 +115,9 @@ public class ROM extends Node implements Element {
 
     @Override
     public void init(Model model) throws NodeException {
+        if (isProgramMemory) {
+            model.addProgRom(this);
+        }
         if (autoLoad) {
             try {
                 data = new DataField(hexFile);
diff --git a/src/main/java/de/neemann/digital/gui/DigitalRemoteInterface.java b/src/main/java/de/neemann/digital/gui/DigitalRemoteInterface.java
index f841482ad..000d91acf 100644
--- a/src/main/java/de/neemann/digital/gui/DigitalRemoteInterface.java
+++ b/src/main/java/de/neemann/digital/gui/DigitalRemoteInterface.java
@@ -21,30 +21,37 @@ public interface DigitalRemoteInterface {
 
     /**
      * Starts the model
+     *
      * @throws RemoteException RemoteException
      */
     void start() throws RemoteException;
 
     /**
      * Starts the model in debug mode
+     *
      * @throws RemoteException RemoteException
      */
     void debug() throws RemoteException;
 
     /**
      * performs a single step
+     *
+     * @return actual position
      * @throws RemoteException RemoteException
      */
-    void doSingleStep() throws RemoteException;
+    String doSingleStep() throws RemoteException;
 
     /**
      * runs model to the next BRK instruction
+     *
+     * @return actual position
      * @throws RemoteException RemoteException
      */
-    void runToBreak() throws RemoteException;
+    String runToBreak() throws RemoteException;
 
     /**
      * stops the model
+     *
      * @throws RemoteException RemoteException
      */
     void stop() throws RemoteException;
diff --git a/src/main/java/de/neemann/digital/gui/Main.java b/src/main/java/de/neemann/digital/gui/Main.java
index 2d459b5a8..711282301 100644
--- a/src/main/java/de/neemann/digital/gui/Main.java
+++ b/src/main/java/de/neemann/digital/gui/Main.java
@@ -52,6 +52,7 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.lang.reflect.InvocationTargetException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
@@ -1019,39 +1020,57 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
     }
 
     @Override
-    public void doSingleStep() {
+    public String doSingleStep() throws RemoteException {
         if (model != null && !realtimeClockRunning) {
-            SwingUtilities.invokeLater(() -> {
-                ArrayList<Clock> cl = model.getClocks();
-                if (cl.size() == 1) {
-                    ObservableValue clkVal = cl.get(0).getClockOutput();
-                    clkVal.setBool(!clkVal.getBool());
-                    try {
-                        model.doStep();
-                        if (clkVal.getBool()) {
-                            clkVal.setBool(!clkVal.getBool());
+            try {
+                SwingUtilities.invokeAndWait(() -> {
+                    ArrayList<Clock> cl = model.getClocks();
+                    if (cl.size() == 1) {
+                        ObservableValue clkVal = cl.get(0).getClockOutput();
+                        clkVal.setBool(!clkVal.getBool());
+                        try {
                             model.doStep();
+                            if (clkVal.getBool()) {
+                                clkVal.setBool(!clkVal.getBool());
+                                model.doStep();
+                            }
+                            circuitComponent.hasChanged();
+                        } catch (NodeException e) {
+                            showErrorAndStopModel(Lang.get("err_remoteExecution"), e);
                         }
-                        circuitComponent.hasChanged();
-                    } catch (NodeException e) {
-                        showErrorAndStopModel(Lang.get("err_remoteExecution"), e);
                     }
-                }
-            });
+                });
+                return getProgRomAddr();
+            } catch (InterruptedException | InvocationTargetException e) {
+                throw new RemoteException("error performing a single step "+e.getMessage());
+            }
         }
+        return null;
+    }
+
+    private String getProgRomAddr() {
+        ArrayList<ROM> roms = model.getProgRoms();
+        if (roms.size()==1)
+            return Long.toHexString(roms.get(0).getRomAddress());
+        return null;
     }
 
     @Override
-    public void runToBreak() {
-        SwingUtilities.invokeLater(() -> {
-            if (model != null && model.isFastRunModel() && !realtimeClockRunning)
-                runToBreakAction.actionPerformed(null);
-        });
+    public String runToBreak() throws RemoteException {
+        try {
+            SwingUtilities.invokeAndWait(() -> {
+                if (model != null && model.isFastRunModel() && !realtimeClockRunning)
+                    runToBreakAction.actionPerformed(null);
+            });
+            return getProgRomAddr();
+        } catch (InterruptedException | InvocationTargetException e) {
+            throw new RemoteException("error performing a run to break "+e.getMessage());
+        }
     }
 
     private void setDebug(boolean debug) throws RemoteException {
         VisualElement rom = getProgramRomFromCircuit();
-        rom.getElementAttributes().set(Keys.SHOW_LISTING, debug);
+        //rom.getElementAttributes().set(Keys.SHOW_LISTING, debug);
         settings.set(Keys.SHOW_DATA_TABLE, debug);
     }
 
diff --git a/src/main/java/de/neemann/digital/gui/remote/DigitalHandler.java b/src/main/java/de/neemann/digital/gui/remote/DigitalHandler.java
index 2ceea3ce4..5cb3c7675 100644
--- a/src/main/java/de/neemann/digital/gui/remote/DigitalHandler.java
+++ b/src/main/java/de/neemann/digital/gui/remote/DigitalHandler.java
@@ -31,34 +31,35 @@ public class DigitalHandler implements HandlerInterface {
         }
 
         try {
-            handle(command.toLowerCase(), args);
-            return "ok";
+            String ret = handle(command.toLowerCase(), args);
+            if (ret != null)
+                return "ok:"+ret;
+            else
+                return "ok";
         } catch (RemoteException e) {
             return e.getMessage();
         }
     }
 
-    private void handle(String command, String args) throws RemoteException {
+    private String handle(String command, String args) throws RemoteException {
         switch (command) {
             case "step":
-                digitalRemoteInterface.doSingleStep();
-                break;
+                return digitalRemoteInterface.doSingleStep();
             case "start":
                 digitalRemoteInterface.start();
-                break;
+                return null;
             case "debug":
                 digitalRemoteInterface.debug();
-                break;
+                return null;
             case "run":
-                digitalRemoteInterface.runToBreak();
-                break;
+                return digitalRemoteInterface.runToBreak();
             case "stop":
                 digitalRemoteInterface.stop();
-                break;
+                return null;
             case "load":
                 File file = new File(args);
                 digitalRemoteInterface.loadRom(file);
-                break;
+                return null;
             default:
                 throw new RemoteException(Lang.get("msg_remoteUnknownCommand", command));
         }