diff --git a/stella/src/common/FrameBufferGL.cxx b/stella/src/common/FrameBufferGL.cxx
index cebbd04ea..582889a10 100644
--- a/stella/src/common/FrameBufferGL.cxx
+++ b/stella/src/common/FrameBufferGL.cxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: FrameBufferGL.cxx,v 1.8 2005-01-04 02:29:28 stephena Exp $
+// $Id: FrameBufferGL.cxx,v 1.9 2005-01-04 19:59:12 stephena Exp $
 //============================================================================
 
 #include <SDL.h>
@@ -120,13 +120,10 @@ bool FrameBufferGL::init()
     return false;
 
   // Check which system we are running under
-  x11Available = false;
-#if UNIX && (!__APPLE__)
+  // Get the system-specific WM information
   SDL_VERSION(&myWMInfo.version);
   if(SDL_GetWMInfo(&myWMInfo) > 0)
-    if(myWMInfo.subsystem == SDL_SYSWM_X11)
-      x11Available = true;
-#endif
+    myWMAvailable = true;
 
   // Get the maximum size of a window for THIS screen
   theMaxZoomLevel = maxWindowSizeForScreen();
diff --git a/stella/src/common/FrameBufferSDL.cxx b/stella/src/common/FrameBufferSDL.cxx
index 63fd0863e..8b0f2a024 100644
--- a/stella/src/common/FrameBufferSDL.cxx
+++ b/stella/src/common/FrameBufferSDL.cxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: FrameBufferSDL.cxx,v 1.1 2004-05-24 17:18:22 stephena Exp $
+// $Id: FrameBufferSDL.cxx,v 1.2 2005-01-04 19:59:13 stephena Exp $
 //============================================================================
 
 #include <SDL.h>
@@ -30,7 +30,7 @@
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 FrameBufferSDL::FrameBufferSDL()
-   :  x11Available(false),
+   :  myWMAvailable(false),
       theZoomLevel(1),
       theMaxZoomLevel(1),
       theAspectRatio(1.0),
@@ -167,28 +167,22 @@ bool FrameBufferSDL::fullScreen()
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 uInt32 FrameBufferSDL::maxWindowSizeForScreen()
 {
-  if(!x11Available)
-    return 4;
+  uInt32 sWidth     = screenWidth();
+  uInt32 sHeight    = screenHeight();
+  uInt32 multiplier = sWidth / myWidth;
 
-#ifdef UNIX
-  // Otherwise, lock the screen and get the width and height
-  myWMInfo.info.x11.lock_func();
-  Display* theX11Display = myWMInfo.info.x11.display;
-  myWMInfo.info.x11.unlock_func();
+  // If screenwidth or height could not be found, use default zoom value
+  if(sWidth == 0 || sHeight == 0)
+    return 2;
 
-  int screenWidth  = DisplayWidth(theX11Display, DefaultScreen(theX11Display));
-  int screenHeight = DisplayHeight(theX11Display, DefaultScreen(theX11Display));
-
-  uInt32 multiplier = screenWidth / myWidth;
   bool found = false;
-
   while(!found && (multiplier > 0))
   {
     // Figure out the desired size of the window
-    int width  = (int) (myWidth * multiplier * theAspectRatio);
-    int height = myHeight * multiplier;
+    uInt32 width  = (uInt32) (myWidth * multiplier * theAspectRatio);
+    uInt32 height = myHeight * multiplier;
 
-    if((width < screenWidth) && (height < screenHeight))
+    if((width < sWidth) && (height < sHeight))
       found = true;
     else
       multiplier--;
@@ -198,9 +192,56 @@ uInt32 FrameBufferSDL::maxWindowSizeForScreen()
     return multiplier;
   else
     return 1;
-#endif
+}
 
-  return 4;
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+uInt32 FrameBufferSDL::screenWidth()
+{
+  uInt32 width = 0;
+
+  if(myWMAvailable)
+  {
+#if defined(UNIX)
+    if(myWMInfo.subsystem == SDL_SYSWM_X11)
+    {
+      myWMInfo.info.x11.lock_func();
+      width = DisplayWidth(myWMInfo.info.x11.display,
+                           DefaultScreen(myWMInfo.info.x11.display));
+      myWMInfo.info.x11.unlock_func();
+    }
+#elif defined(WIN32)
+    width = (uInt32) GetSystemMetrics(SM_CXSCREEN);
+#elif defined(MAC_OSX)
+  // FIXME - add OSX Desktop code here (I don't think SDL supports it yet)
+#endif
+  }
+
+  return width;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+uInt32 FrameBufferSDL::screenHeight()
+{
+  uInt32 height = 0;
+
+  if(myWMAvailable)
+  {
+#if defined(UNIX)
+    if(myWMInfo.subsystem == SDL_SYSWM_X11)
+    {
+      myWMInfo.info.x11.lock_func();
+      height = DisplayHeight(myWMInfo.info.x11.display,
+                             DefaultScreen(myWMInfo.info.x11.display));
+      myWMInfo.info.x11.unlock_func();
+    }
+#elif defined(WIN32)
+    height = (uInt32) GetSystemMetrics(SM_CYSCREEN);
+#elif defined(MAC_OSX)
+  // FIXME - add OSX Desktop code here (I don't think SDL supports it yet)
+#endif
+  }
+
+  return height;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
diff --git a/stella/src/common/FrameBufferSDL.hxx b/stella/src/common/FrameBufferSDL.hxx
index 4c79dc1ee..64e1c225e 100644
--- a/stella/src/common/FrameBufferSDL.hxx
+++ b/stella/src/common/FrameBufferSDL.hxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: FrameBufferSDL.hxx,v 1.3 2004-06-23 00:15:32 stephena Exp $
+// $Id: FrameBufferSDL.hxx,v 1.4 2005-01-04 19:59:13 stephena Exp $
 //============================================================================
 
 #ifndef FRAMEBUFFER_SDL_HXX
@@ -35,7 +35,7 @@
   the core FrameBuffer.
 
   @author  Stephen Anthony
-  @version $Id: FrameBufferSDL.hxx,v 1.3 2004-06-23 00:15:32 stephena Exp $
+  @version $Id: FrameBufferSDL.hxx,v 1.4 2005-01-04 19:59:13 stephena Exp $
 */
 class FrameBufferSDL : public FrameBuffer
 {
@@ -102,6 +102,16 @@ class FrameBufferSDL : public FrameBuffer
     */
     uInt32 imageHeight() { return myDimensions.h; }
 
+    /**
+      This routine is called to get the width of the system desktop.
+    */
+    uInt32 screenWidth();
+
+    /**
+      This routine is called to get the height of the system desktop.
+    */
+    uInt32 screenHeight();
+
     /**
       Set the title and icon for the main SDL window.
     */
@@ -157,8 +167,8 @@ class FrameBufferSDL : public FrameBuffer
     // (these may be different than the screen/window dimensions)
     SDL_Rect myDimensions;
 
-    // Indicates if we are running under X11
-    bool x11Available;
+    // Indicates if the system-specific WM information is available
+    bool myWMAvailable;
 
     // Indicates the current zoom level of the SDL screen
     uInt32 theZoomLevel;
diff --git a/stella/src/common/FrameBufferSoft.cxx b/stella/src/common/FrameBufferSoft.cxx
index 62b7c9efe..68b0914da 100644
--- a/stella/src/common/FrameBufferSoft.cxx
+++ b/stella/src/common/FrameBufferSoft.cxx
@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: FrameBufferSoft.cxx,v 1.4 2005-01-03 19:16:09 stephena Exp $
+// $Id: FrameBufferSoft.cxx,v 1.5 2005-01-04 19:59:13 stephena Exp $
 //============================================================================
 
 #include <SDL.h>
@@ -69,16 +69,12 @@ bool FrameBufferSoft::init()
   if(SDL_Init(initflags) < 0)
     return false;
 
-  // Check which system we are running under
-  x11Available = false;
-#if UNIX && (!__APPLE__)
+  // Get the system-specific WM information
   SDL_VERSION(&myWMInfo.version);
   if(SDL_GetWMInfo(&myWMInfo) > 0)
-    if(myWMInfo.subsystem == SDL_SYSWM_X11)
-      x11Available = true;
-#endif
+    myWMAvailable = true;
 
-  // Get the maximum size of a window for THIS screen
+  // Get the maximum size of a window for the desktop
   theMaxZoomLevel = maxWindowSizeForScreen();
 
   // Check to see if window size will fit in the screen