diff --git a/src/common/FrameBufferSDL2.cxx b/src/common/FrameBufferSDL2.cxx
index a7687b8c4..6da6735a0 100644
--- a/src/common/FrameBufferSDL2.cxx
+++ b/src/common/FrameBufferSDL2.cxx
@@ -33,9 +33,7 @@ FrameBufferSDL2::FrameBufferSDL2(OSystem& osystem)
     myWindow(nullptr),
     myRenderer(nullptr),
     myCenter(false),
-    myRenderTargetSupport(false),
-    myScaleX(1),
-    myScaleY(1)
+    myRenderTargetSupport(false)
 {
   ASSERT_MAIN_THREAD;
 
@@ -326,7 +324,7 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
   myRenderer = SDL_CreateRenderer(myWindow, -1, renderFlags);
 
   detectFeatures();
-  calculateScaleFactors();
+  determineDimensions();
 
   if(myRenderer == nullptr)
   {
@@ -520,28 +518,14 @@ bool FrameBufferSDL2::hasRenderTargetSupport() const
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void FrameBufferSDL2::calculateScaleFactors()
+void FrameBufferSDL2::determineDimensions()
 {
+  SDL_GetWindowSize(myWindow, &myWindowW, &myWindowH);
+
   if (myRenderer == nullptr) {
-    myScaleX = myScaleY = 1;
-    return;
+    myRenderW = myWindowW;
+    myRenderH = myWindowH;
+  } else {
+    SDL_GetRendererOutputSize(myRenderer, &myRenderW, &myRenderH);
   }
-
-  int windowW, windowH, renderW, renderH;
-
-  SDL_GetWindowSize(myWindow, &windowW, &windowH);
-  SDL_GetRendererOutputSize(myRenderer, &renderW, &renderH);
-
-  myScaleX = renderW / windowW;
-  myScaleY = renderH / windowH;
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt8 FrameBufferSDL2::scaleX() const {
-  return myScaleX;
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt8 FrameBufferSDL2::scaleY() const {
-  return myScaleY;
 }
diff --git a/src/common/FrameBufferSDL2.hxx b/src/common/FrameBufferSDL2.hxx
index d75610829..eefbeae36 100644
--- a/src/common/FrameBufferSDL2.hxx
+++ b/src/common/FrameBufferSDL2.hxx
@@ -135,14 +135,14 @@ class FrameBufferSDL2 : public FrameBuffer
     bool hasRenderTargetSupport() const;
 
     /**
-      Retina scale factor, x direction;
+      Transform from window to renderer coordinates, x direction
      */
-    uInt8 scaleX() const;
+    int scaleX(int x) const { return (x * myRenderW) / myWindowW; }
 
     /**
-      Retina scale Factor, y direction;
+      Transform from window to renderer coordinates, y direction
      */
-    uInt8 scaleY() const;
+    int scaleY(int y) const { return (y * myRenderH) / myWindowH; }
 
   protected:
     //////////////////////////////////////////////////////////////////////
@@ -218,7 +218,10 @@ class FrameBufferSDL2 : public FrameBuffer
      */
     bool detectRenderTargetSupport();
 
-    void calculateScaleFactors();
+    /**
+      Determine window and renderer dimensions.
+     */
+    void determineDimensions();
 
   private:
     // The SDL video buffer
@@ -237,8 +240,8 @@ class FrameBufferSDL2 : public FrameBuffer
     // Does the renderer support render targets?
     bool myRenderTargetSupport;
 
-    // Retina scale factors
-    uInt32 myScaleX, myScaleY;
+    // Window and renderer dimensions
+    int myWindowW, myWindowH, myRenderW, myRenderH;
 
   private:
     // Following constructors and assignment operators not supported
diff --git a/src/common/sdl_blitter/BilinearBlitter.cxx b/src/common/sdl_blitter/BilinearBlitter.cxx
index 0cfacbcba..e92714159 100644
--- a/src/common/sdl_blitter/BilinearBlitter.cxx
+++ b/src/common/sdl_blitter/BilinearBlitter.cxx
@@ -47,21 +47,20 @@ void BilinearBlitter::reinitialize(
   myRecreateTextures = myRecreateTextures || !(
     mySrcRect.w == srcRect.w &&
     mySrcRect.h == srcRect.h &&
-    myDstRect.w == destRect.w &&
-    myDstRect.h == destRect.h &&
+    myDstRect.w == myFB.scaleX(destRect.w) &&
+    myDstRect.h == myFB.scaleY(destRect.h) &&
     attributes == myAttributes &&
     myStaticData == staticData
    );
 
    myStaticData = staticData;
    mySrcRect = srcRect;
-   myDstRect = destRect;
    myAttributes = attributes;
 
-   myDstRect.x *= myFB.scaleX();
-   myDstRect.y *= myFB.scaleY();
-   myDstRect.w *= myFB.scaleX();
-   myDstRect.h *= myFB.scaleY();
+   myDstRect.x = myFB.scaleX(destRect.x);
+   myDstRect.y = myFB.scaleY(destRect.y);
+   myDstRect.w = myFB.scaleX(destRect.w);
+   myDstRect.h = myFB.scaleY(destRect.h);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -92,13 +91,13 @@ void BilinearBlitter::blit(SDL_Surface& surface)
 
   SDL_Texture* texture = myTexture;
 
-    if(myStaticData == nullptr) {
-      SDL_UpdateTexture(myTexture, &mySrcRect, surface.pixels, surface.pitch);
-      myTexture = mySecondaryTexture;
-      mySecondaryTexture = texture;
-    }
+  if(myStaticData == nullptr) {
+    SDL_UpdateTexture(myTexture, &mySrcRect, surface.pixels, surface.pitch);
+    myTexture = mySecondaryTexture;
+    mySecondaryTexture = texture;
+  }
 
-    SDL_RenderCopy(myFB.renderer(), texture, &mySrcRect, &myDstRect);
+  SDL_RenderCopy(myFB.renderer(), texture, &mySrcRect, &myDstRect);
 }
 
 
diff --git a/src/common/sdl_blitter/QisBlitter.cxx b/src/common/sdl_blitter/QisBlitter.cxx
index a9dd85292..b4c2a6750 100644
--- a/src/common/sdl_blitter/QisBlitter.cxx
+++ b/src/common/sdl_blitter/QisBlitter.cxx
@@ -55,21 +55,20 @@ void QisBlitter::reinitialize(
   myRecreateTextures = myRecreateTextures || !(
     mySrcRect.w == srcRect.w &&
     mySrcRect.h == srcRect.h &&
-    myDstRect.w == destRect.w &&
-    myDstRect.h == destRect.h &&
+    myDstRect.w == myFB.scaleX(destRect.w) &&
+    myDstRect.h == myFB.scaleY(destRect.h) &&
     attributes == myAttributes &&
     myStaticData == staticData
    );
 
    myStaticData = staticData;
    mySrcRect = srcRect;
-   myDstRect = destRect;
    myAttributes = attributes;
 
-   myDstRect.x *= myFB.scaleX();
-   myDstRect.y *= myFB.scaleY();
-   myDstRect.w *= myFB.scaleX();
-   myDstRect.h *= myFB.scaleY();
+   myDstRect.x = myFB.scaleX(destRect.x);
+   myDstRect.y = myFB.scaleY(destRect.y);
+   myDstRect.w = myFB.scaleX(destRect.w);
+   myDstRect.h = myFB.scaleY(destRect.h);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -100,16 +99,16 @@ void QisBlitter::blit(SDL_Surface& surface)
 
   SDL_Texture* texture = myIntermediateTexture;
 
-    if(myStaticData == nullptr) {
-      SDL_UpdateTexture(mySrcTexture, &mySrcRect, surface.pixels, surface.pitch);
+  if(myStaticData == nullptr) {
+    SDL_UpdateTexture(mySrcTexture, &mySrcRect, surface.pixels, surface.pitch);
 
-      blitToIntermediate();
+    blitToIntermediate();
 
-      myIntermediateTexture = mySecondaryIntermedateTexture;
-      mySecondaryIntermedateTexture = texture;
-    }
+    myIntermediateTexture = mySecondaryIntermedateTexture;
+    mySecondaryIntermedateTexture = texture;
+  }
 
-    SDL_RenderCopy(myFB.renderer(), texture, &myIntermediateRect, &myDstRect);
+  SDL_RenderCopy(myFB.renderer(), texture, &myIntermediateRect, &myDstRect);
 }
 
 
diff --git a/src/macos/Info-Stella.plist b/src/macos/Info-Stella.plist
index ac022cb7c..8f37a40c3 100644
--- a/src/macos/Info-Stella.plist
+++ b/src/macos/Info-Stella.plist
@@ -61,6 +61,8 @@
 		<key>x86_64</key>
 		<string>10.7.0</string>
 	</dict>
+	<key>NSHighResolutionCapable</key>
+	<true/>
 	<key>NSMainNibFile</key>
 	<string>SDLMain</string>
 	<key>NSPrincipalClass</key>