diff --git a/headers/private/servers/app/DisplayDriver.h b/headers/private/servers/app/DisplayDriver.h
index db27b3c73e..0edeb5e199 100644
--- a/headers/private/servers/app/DisplayDriver.h
+++ b/headers/private/servers/app/DisplayDriver.h
@@ -303,8 +303,8 @@ class DisplayDriver {
 
 	// These two will rarely be implemented by subclasses,
 	// but it still needs to be possible
-	virtual bool				Lock(bigtime_t timeout = B_INFINITE_TIMEOUT);
-	virtual void				Unlock();
+	virtual bool				Lock(bigtime_t timeout = B_INFINITE_TIMEOUT) = 0;
+	virtual void				Unlock() = 0;
 
 	// display mode access
 	virtual void				SetMode(const display_mode &mode);
@@ -358,8 +358,6 @@ class DisplayDriver {
 	virtual	void				ConstrainClippingRegion(BRegion *reg) = 0;
 
  protected:
-			BLocker				fLocker;
-
 			CursorHandler		fCursorHandler;
 
 			display_mode		fDisplayMode;
diff --git a/headers/private/servers/app/DisplayDriverImpl.h b/headers/private/servers/app/DisplayDriverImpl.h
index a7d88b0b7d..e5724264bb 100644
--- a/headers/private/servers/app/DisplayDriverImpl.h
+++ b/headers/private/servers/app/DisplayDriverImpl.h
@@ -282,8 +282,8 @@ class DisplayDriverImpl : public DisplayDriver {
 		
 	// These two will rarely be implemented by subclasses,
 	// but it still needs to be possible
-//	virtual bool				Lock(bigtime_t timeout = B_INFINITE_TIMEOUT);
-//	virtual void				Unlock();
+	virtual bool				Lock(bigtime_t timeout = B_INFINITE_TIMEOUT);
+	virtual void				Unlock();
 
 	virtual bool				DumpToFile(const char *path);
 	virtual ServerBitmap*		DumpToBitmap();
@@ -406,15 +406,8 @@ friend class WinBorder;
 	virtual void				StrokeSolidRect(const BRect &rect,
 												const RGBColor &color);
 
-
-//	PatternHandler fDrawPattern;
-//	RGBColor fDrawColor;
-//	int fLineThickness;
-	
-//	accelerant_device_info fAccDeviceInfo;
-	
-	
-//	DrawData fDrawData;
+ protected:
+			BLocker				fLocker;
 };
 
 #endif
diff --git a/headers/private/servers/app/ServerConfig.h b/headers/private/servers/app/ServerConfig.h
index f32e8609e1..024e6aa373 100644
--- a/headers/private/servers/app/ServerConfig.h
+++ b/headers/private/servers/app/ServerConfig.h
@@ -36,6 +36,7 @@
 
 // Display driver to be used by the server.
 #define DISPLAYDRIVER PAINTERDRIVER
+//#define DISPLAYDRIVER VIEWDRIVER
 
 // Uncomment this if the DisplayDriver should only rely on drawing functions implemented
 // in software even though hardware-accelerated functions are available