diff --git a/src/debugger/Debugger.cxx b/src/debugger/Debugger.cxx
index 62ee95a74..b8c8ffe97 100644
--- a/src/debugger/Debugger.cxx
+++ b/src/debugger/Debugger.cxx
@@ -166,12 +166,17 @@ Debugger::~Debugger()
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Debugger::initialize()
 {
-  // Get the dialog size
-  const GUI::Size& size = myOSystem->settings().getSize("dbg.res");
-  myWidth = BSPF_max(size.w, 0u);
-  myHeight = BSPF_max(size.h, 0u);
-  myWidth = BSPF_max(myWidth, (uInt32)DebuggerDialog::kSmallFontMinW);
+  const GUI::Size& s = myOSystem->settings().getSize("dbg.res");
+  const GUI::Size& d = myOSystem->frameBuffer().desktopSize();
+  myWidth = s.w;  myHeight = s.h;
+
+  // The debugger dialog is resizable, within certain bounds
+  // We check those bounds now
+  myWidth  = BSPF_max(myWidth, (uInt32)DebuggerDialog::kSmallFontMinW);
   myHeight = BSPF_max(myHeight, (uInt32)DebuggerDialog::kSmallFontMinH);
+  myWidth  = BSPF_min(myWidth, (uInt32)d.w);
+  myHeight = BSPF_min(myHeight, (uInt32)d.h);
+
   myOSystem->settings().setValue("dbg.res", GUI::Size(myWidth, myHeight));
 
   delete myBaseDialog;  myBaseDialog = myDialog = NULL;
diff --git a/src/debugger/Debugger.hxx b/src/debugger/Debugger.hxx
index 9d9731bd8..e39a8d4a2 100644
--- a/src/debugger/Debugger.hxx
+++ b/src/debugger/Debugger.hxx
@@ -231,7 +231,7 @@ class Debugger : public DialogContainer
     /* These are now exposed so Expressions can use them. */
     int peek(int addr) { return mySystem.peek(addr); }
     int dpeek(int addr) { return mySystem.peek(addr) | (mySystem.peek(addr+1) << 8); }
-    int getAccessFlags(uInt16 addr)
+    int getAccessFlags(uInt16 addr) const
       { return mySystem.getAccessFlags(addr); }
     void setAccessFlags(uInt16 addr, uInt8 flags)
       { mySystem.setAccessFlags(addr, flags); }
diff --git a/src/emucore/Cart4A50.cxx b/src/emucore/Cart4A50.cxx
index 84083c5e4..4acf2e145 100644
--- a/src/emucore/Cart4A50.cxx
+++ b/src/emucore/Cart4A50.cxx
@@ -203,7 +203,7 @@ bool Cartridge4A50::poke(uInt16 address, uInt8 value)
 } 
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt8 Cartridge4A50::getAccessFlags(uInt16 address)
+uInt8 Cartridge4A50::getAccessFlags(uInt16 address) const
 {
   if((address & 0x1800) == 0x1000)           // 2K region from 0x1000 - 0x17ff
   {
diff --git a/src/emucore/Cart4A50.hxx b/src/emucore/Cart4A50.hxx
index be2472d06..9780059c3 100644
--- a/src/emucore/Cart4A50.hxx
+++ b/src/emucore/Cart4A50.hxx
@@ -158,7 +158,7 @@ class Cartridge4A50 : public Cartridge
       @param address The address to modify
       @param flags A bitfield of DisasmType directives for the given address
     */
-    uInt8 getAccessFlags(uInt16 address);
+    uInt8 getAccessFlags(uInt16 address) const;
     void setAccessFlags(uInt16 address, uInt8 flags);
 
     /**
diff --git a/src/emucore/CartAR.cxx b/src/emucore/CartAR.cxx
index 4db90365d..bad5d93a7 100644
--- a/src/emucore/CartAR.cxx
+++ b/src/emucore/CartAR.cxx
@@ -223,7 +223,7 @@ bool CartridgeAR::poke(uInt16 addr, uInt8)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt8 CartridgeAR::getAccessFlags(uInt16 address)
+uInt8 CartridgeAR::getAccessFlags(uInt16 address) const
 {
   return myCodeAccessBase[(address & 0x07FF) +
            myImageOffset[(address & 0x0800) ? 1 : 0]];
diff --git a/src/emucore/CartAR.hxx b/src/emucore/CartAR.hxx
index f8dc646a9..3ee230a3d 100644
--- a/src/emucore/CartAR.hxx
+++ b/src/emucore/CartAR.hxx
@@ -174,7 +174,7 @@ class CartridgeAR : public Cartridge
       @param address The address to modify
       @param flags A bitfield of DisasmType directives for the given address
     */
-    uInt8 getAccessFlags(uInt16 address);
+    uInt8 getAccessFlags(uInt16 address) const;
     void setAccessFlags(uInt16 address, uInt8 flags);
 
     // Handle a change to the bank configuration
diff --git a/src/emucore/CartFE.cxx b/src/emucore/CartFE.cxx
index 7035c185c..b962c538c 100644
--- a/src/emucore/CartFE.cxx
+++ b/src/emucore/CartFE.cxx
@@ -90,7 +90,7 @@ bool CartridgeFE::poke(uInt16, uInt8)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt8 CartridgeFE::getAccessFlags(uInt16 address)
+uInt8 CartridgeFE::getAccessFlags(uInt16 address) const
 {
   return myCodeAccessBase[(address & 0x0FFF) +
             (((address & 0x2000) == 0) ? 4096 : 0)];
diff --git a/src/emucore/CartFE.hxx b/src/emucore/CartFE.hxx
index 969702975..6fdddc4ae 100644
--- a/src/emucore/CartFE.hxx
+++ b/src/emucore/CartFE.hxx
@@ -177,7 +177,7 @@ class CartridgeFE : public Cartridge
       @param address The address to modify
       @param flags A bitfield of DisasmType directives for the given address
     */
-    uInt8 getAccessFlags(uInt16 address);
+    uInt8 getAccessFlags(uInt16 address) const;
     void setAccessFlags(uInt16 address, uInt8 flags);
 
   private:
diff --git a/src/emucore/Device.hxx b/src/emucore/Device.hxx
index 51aaa65f4..f8ccf53b6 100644
--- a/src/emucore/Device.hxx
+++ b/src/emucore/Device.hxx
@@ -117,7 +117,7 @@ class Device : public Serializable
       @param address The address to modify
       @param flags A bitfield of DisasmType directives for the given address
     */
-    virtual uInt8 getAccessFlags(uInt16 address) { return 0; }
+    virtual uInt8 getAccessFlags(uInt16 address) const { return 0; }
     virtual void setAccessFlags(uInt16 address, uInt8 flags) { }
 
   protected:
diff --git a/src/emucore/FrameBuffer.cxx b/src/emucore/FrameBuffer.cxx
index 31c30ca09..7d686018b 100644
--- a/src/emucore/FrameBuffer.cxx
+++ b/src/emucore/FrameBuffer.cxx
@@ -83,7 +83,7 @@ bool FrameBuffer::initialize()
   // Check the 'maxres' setting, which is an undocumented developer feature
   // that specifies the desktop size (not normally set)
   const GUI::Size& s = myOSystem.settings().getSize("maxres");
-  if(s.w > 0 && s.h > 0)
+  if(s.isValid())
   {
     query_w = s.w;
     query_h = s.h;
diff --git a/src/emucore/System.cxx b/src/emucore/System.cxx
index c5b1f3f15..c9a4e47f6 100644
--- a/src/emucore/System.cxx
+++ b/src/emucore/System.cxx
@@ -241,7 +241,7 @@ void System::poke(uInt16 addr, uInt8 value)
 {
   uInt16 page = (addr & myAddressMask) >> myPageShift;
   PageAccess& access = myPageAccessTable[page];
-  
+
   // See if this page uses direct accessing or not 
   if(access.directPokeBase)
   {
@@ -262,7 +262,7 @@ void System::poke(uInt16 addr, uInt8 value)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt8 System::getAccessFlags(uInt16 addr)
+uInt8 System::getAccessFlags(uInt16 addr) const
 {
 #ifdef DEBUGGER_SUPPORT
   PageAccess& access = myPageAccessTable[(addr & myAddressMask) >> myPageShift];
@@ -289,18 +289,6 @@ void System::setAccessFlags(uInt16 addr, uInt8 flags)
 #endif
 }
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void System::lockDataBus()
-{
-  myDataBusLocked = true;
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void System::unlockDataBus()
-{
-  myDataBusLocked = false;
-}
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool System::save(Serializer& out) const
 {
diff --git a/src/emucore/System.hxx b/src/emucore/System.hxx
index f073f1f88..b04386055 100644
--- a/src/emucore/System.hxx
+++ b/src/emucore/System.hxx
@@ -266,15 +266,15 @@ class System : public Serializable
       use System.peek() to examine memory/registers without changing
       the state of the system.
     */
-    void lockDataBus();
-    void unlockDataBus();
+    void lockDataBus()   { myDataBusLocked = true;  }
+    void unlockDataBus() { myDataBusLocked = false; }
 
     /**
       Access and modify the disassembly type flags for the given
       address.  Note that while any flag can be used, the disassembly
       only really acts on CODE/GFX/PGFX/DATA/ROW.
     */
-    uInt8 getAccessFlags(uInt16 address);
+    uInt8 getAccessFlags(uInt16 address) const;
     void setAccessFlags(uInt16 address, uInt8 flags);
 
   public:
diff --git a/src/gui/Rect.hxx b/src/gui/Rect.hxx
index 09195c0f5..7c65c30bc 100644
--- a/src/gui/Rect.hxx
+++ b/src/gui/Rect.hxx
@@ -38,7 +38,7 @@ struct Point
   int y;  //!< The vertical part of the point
 
   Point() : x(0), y(0) {};
-  Point(const Point & p) : x(p.x), y(p.y) {};
+  Point(const Point& p) : x(p.x), y(p.y) {};
   explicit Point(int x1, int y1) : x(x1), y(y1) {};
   Point(const string& p) {
     char c = '\0';
@@ -64,7 +64,7 @@ struct Size
   uInt32 h;  //!< The height part of the size
 
   Size() : w(0), h(0) {};
-  Size(const Size & s) : w(s.w), h(s.h) {};
+  Size(const Size& s) : w(s.w), h(s.h) {};
   explicit Size(uInt32 w1, uInt32 h1) : w(w1), h(h1) {};
   Size(const string& s) {
     char c = '\0';
@@ -74,9 +74,15 @@ struct Size
     if(c != 'x')
       w = h = 0;
   }
-  Size & operator=(const Size & s) { w = s.w; h = s.h; return *this; };
-  bool operator==(const Size & s) const { return w == s.w && h == s.h; };
-  bool operator!=(const Size & s) const { return w != s.w || h != s.h; };
+  bool isValid() const { return w > 0 && h > 0; }
+
+  Size& operator=(const Size& s) { w = s.w; h = s.h; return *this; };
+  bool operator==(const Size& s) const { return w == s.w && h == s.h; };
+  bool operator!=(const Size& s) const { return w != s.w || h != s.h; };
+  bool operator<(const Size& s)  const { return w < s.w && h < s.h;   };
+  bool operator<=(const Size& s) const { return w <= s.w && h <= s.h; };
+  bool operator>(const Size& s)  const { return w > s.w && h > s.h;   };
+  bool operator>=(const Size& s) const { return w >= s.w && h >= s.h; };
 
   friend ostream& operator<<(ostream& os, const Size& s) {
     os << s.w << "x" << s.h;
@@ -107,6 +113,7 @@ struct Rect
   uInt32 bottom, right;    //!< The point at the bottom right of the rectangle (not part of the rect).
 
   Rect() : top(0), left(0), bottom(0), right(0) {}
+  Rect(const Rect& s) : top(s.top), left(s.left), bottom(s.bottom), right(s.right) {}
   Rect(uInt32 w, uInt32 h) : top(0), left(0), bottom(h), right(w) {}
   Rect(const Point& p, uInt32 w, uInt32 h) : top(p.y), left(p.x), bottom(h), right(w) {}
   Rect(uInt32 x1, uInt32 y1, uInt32 x2, uInt32 y2) : top(y1), left(x1), bottom(y2), right(x2)