diff --git a/els-f280049c/Configuration.h b/els-f280049c/Configuration.h
index 5486775..3216572 100644
--- a/els-f280049c/Configuration.h
+++ b/els-f280049c/Configuration.h
@@ -126,6 +126,21 @@
 #define HARDWARE_VERSION 2
 
 
+
+
+//================================================================================
+//                                FEATURES
+//
+// Additional features that can be enabled for your configuration.
+//================================================================================
+
+// Ignore all key presses when the machine is running.  Normally, only the mode
+// and direction keys are ignored.
+//#define IGNORE_ALL_KEYS_WHEN_RUNNING
+
+
+
+
 //================================================================================
 //                               CPU / TIMING
 //
diff --git a/els-f280049c/UserInterface.cpp b/els-f280049c/UserInterface.cpp
index ae51647..4bca9a1 100644
--- a/els-f280049c/UserInterface.cpp
+++ b/els-f280049c/UserInterface.cpp
@@ -156,15 +156,24 @@ void UserInterface :: loop( void )
         }
     }
 
-    // these keys can be operated when the machine is running
-    if( keys.bit.UP )
-    {
-        newFeed = feedTable->next();
-    }
-    if( keys.bit.DOWN )
-    {
-        newFeed = feedTable->previous();
+#ifdef IGNORE_ALL_KEYS_WHEN_RUNNING
+    if( currentRpm == 0 )
+        {
+#endif // IGNORE_ALL_KEYS_WHEN_RUNNING
+
+        // these keys can be operated when the machine is running
+        if( keys.bit.UP )
+        {
+            newFeed = feedTable->next();
+        }
+        if( keys.bit.DOWN )
+        {
+            newFeed = feedTable->previous();
+        }
+
+#ifdef IGNORE_ALL_KEYS_WHEN_RUNNING
     }
+#endif // IGNORE_ALL_KEYS_WHEN_RUNNING
 
     // if we have changed the feed
     if( newFeed != NULL ) {