diff --git a/Changes.txt b/Changes.txt
index c2bc9b4e5..d2d995e9e 100644
--- a/Changes.txt
+++ b/Changes.txt
@@ -97,6 +97,8 @@
 
   * Added option to save and load all TimeMachine states at once.
 
+  * Added option to automatically save states when exiting emulation.
+
   * Added option to change pitch of Pitfall II music.
 
   * ROM Info Launcher can now display multiple lines per property and
diff --git a/docs/graphics/options_developer.png b/docs/graphics/options_developer.png
index 33c42a1ae..8d345f9aa 100644
Binary files a/docs/graphics/options_developer.png and b/docs/graphics/options_developer.png differ
diff --git a/docs/graphics/options_developer_emulation.png b/docs/graphics/options_developer_emulation.png
index 5d31a0e5c..6b8009f35 100644
Binary files a/docs/graphics/options_developer_emulation.png and b/docs/graphics/options_developer_emulation.png differ
diff --git a/docs/graphics/options_developer_timemachine.png b/docs/graphics/options_developer_timemachine.png
index 325b3f1de..8c66c2af5 100644
Binary files a/docs/graphics/options_developer_timemachine.png and b/docs/graphics/options_developer_timemachine.png differ
diff --git a/docs/index.html b/docs/index.html
index 82eb1c9e4..e38dbe470 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -2617,10 +2617,20 @@
           If disabled, use the last databus value for those pins instead.</td>
     </tr><tr>
       <td><pre>-dev.rwportbreak &lt;1|0&gt;</pre></td>
-      <td>Since the 2600 has no dedicated R/W line, different addresses are used
-      for RAM read or write access. If the code reads from such a write address, this causes
-    an unwanted, semi-random write to that address.
-    When this option is enabled, such reads interrupt emulation and the debugger is entered.</td>
+      <td>Since the 2600 has no dedicated R/W line, different addresses are
+        used for RAM read or write access.</br>
+      	If the code reads from such a write address, this causes an unwanted,
+      	semi-random write to that address.</br>
+    	When this option is enabled, such reads interrupt emulation and the
+    	debugger is entered.</td>
+    </tr><tr>
+      <td><pre>-dev.wrportbreak &lt;1|0&gt;</pre></td>
+      <td>Same as above.</br>
+        If the code writes to such a read address, nothing happens. But a
+        developer should be made aware of it, because this indicates a problem
+        with the code.</br>
+    	When this option is enabled, such writes interrupt emulation and the
+    	debugger is entered.</td>
     </tr><tr>
       <td><pre>-dev.thumb.trapfatal &lt;1|0&gt;</pre></td>
       <td>When enabled, this allows the Thumb ARM emulation to
@@ -3244,6 +3254,11 @@
             <td>A read from a write port interrupts emulation and the debugger is entered.</td>
             <td><span style="white-space:nowrap">-dev.rwportbreak</span></td>
           </tr>
+          <tr>
+            <td>Break on write to ...</td>
+            <td>A write to a read port interrupts emulation and the debugger is entered.</td>
+            <td><span style="white-space:nowrap">-dev.wrportbreak</span></td>
+          </tr>
           <tr>
             <td>Fatal ARM emulation ...</td>
             <td>Thumb ARM emulation throws an exception and enters the debugger on fatal errors</td>
@@ -3364,6 +3379,12 @@
               Automatically save no, current or all states when exiting emulation.
             </td>
             <td>-saveonexit</td>
+          </tr><tr>
+            <td>Automatically switch...</td>
+            <td>
+              Automatically switch to the next available save state slot after saving a ROM state file.
+            </td>
+            <td>-autoslot</td>
           </tr>
         </table>
       </td>
diff --git a/src/emucore/Settings.cxx b/src/emucore/Settings.cxx
index 366e85307..4689be2ed 100644
--- a/src/emucore/Settings.cxx
+++ b/src/emucore/Settings.cxx
@@ -465,10 +465,11 @@ void Settings::usage() const
     << "                                scaling/effects)\n"
     << "  -ssinterval   <number>       Number of seconds between snapshots in\n"
     << "                                continuous snapshot mode\n"
-    << "  -autoslot     <1|0>          Automatically switch to next save slot when\n"
-    << "                                state saving\n"
+    << endl
     << "  -saveonexit   <none|current  Automatically save state(s) when exiting emulation\n"
     << "                 all>\n"
+    << "  -autoslot     <1|0>          Automatically switch to next save slot when\n"
+    << "                                state saving\n"
     << endl
     << "  -rominfo      <rom>          Display detailed information for the given ROM\n"
     << "  -listrominfo                 Display contents of stella.pro, one line per ROM\n"
@@ -588,6 +589,7 @@ void Settings::usage() const
     << "                                    read/peek\n"
 #ifdef DEBUGGER_SUPPORT
     << "  -dev.rwportbreak      <1|0>      Debugger breaks on reads from write ports\n"
+    << "  -dev.wrportbreak      <1|0>      Debugger breaks on writes to read ports\n"
 #endif
     << "  -dev.thumb.trapfatal  <1|0>      Determines whether errors in ARM emulation\n"
     << "                                    throw an exception\n"
diff --git a/src/gui/DeveloperDialog.cxx b/src/gui/DeveloperDialog.cxx
index 85be63fdf..28ecf6e7b 100644
--- a/src/gui/DeveloperDialog.cxx
+++ b/src/gui/DeveloperDialog.cxx
@@ -494,6 +494,11 @@ void DeveloperDialog::addTimeMachineTab(const GUI::Font& font)
   wid.push_back(r);
   ypos += lineHeight + VGAP;
 
+
+  myAutoSlotWidget = new CheckboxWidget(myTab, font, HBORDER, ypos + 1, "Automatically switch save state slots");
+  wid.push_back(myAutoSlotWidget);
+  ypos += lineHeight + VGAP;
+
   // Add message concerning usage
   const GUI::Font& infofont = instance().frameBuffer().infoFont();
   ypos = myTab->getHeight() - 5 - fontHeight - infofont.getFontHeight() - 10;
@@ -841,6 +846,8 @@ void DeveloperDialog::loadConfig()
   // Save on exit
   string saveOnExit = instance().settings().getString("saveonexit");
   mySaveOnExitGroup->setSelected(saveOnExit == "all" ? 2 : saveOnExit == "current" ? 1 : 0);
+  // Automatically change save state slots
+  myAutoSlotWidget->setState(instance().settings().getBool("autoslot"));
 
 #ifdef DEBUGGER_SUPPORT
   uInt32 w, h;
@@ -922,6 +929,8 @@ void DeveloperDialog::saveConfig()
   int saveOnExit = mySaveOnExitGroup->getSelected();
   instance().settings().setValue("saveonexit",
     saveOnExit == 0 ? "none" : saveOnExit == 1 ? "current" : "all");
+  // Automatically change save state slots
+  instance().settings().setValue("autoslot", myAutoSlotWidget->getState());
 
 #ifdef DEBUGGER_SUPPORT
   // Debugger font style
@@ -1014,6 +1023,7 @@ void DeveloperDialog::setDefaults()
 
       setWidgetStates(set);
       mySaveOnExitGroup->setSelected(0);
+      myAutoSlotWidget->setState(false);
       break;
 
     case 4: // Debugger options
diff --git a/src/gui/DeveloperDialog.hxx b/src/gui/DeveloperDialog.hxx
index cb11990ae..ddee5468d 100644
--- a/src/gui/DeveloperDialog.hxx
+++ b/src/gui/DeveloperDialog.hxx
@@ -136,6 +136,7 @@ class DeveloperDialog : public Dialog
     PopUpWidget*        myStateIntervalWidget{nullptr};
     PopUpWidget*        myStateHorizonWidget{nullptr};
     RadioButtonGroup*   mySaveOnExitGroup{nullptr};
+    CheckboxWidget*     myAutoSlotWidget{nullptr};
 
 #ifdef DEBUGGER_SUPPORT
     // Debugger UI widgets