diff --git a/src/servers/app/OffscreenWindowLayer.cpp b/src/servers/app/OffscreenWindowLayer.cpp
index 2c0d38e0ef..1a1bf146ff 100644
--- a/src/servers/app/OffscreenWindowLayer.cpp
+++ b/src/servers/app/OffscreenWindowLayer.cpp
@@ -26,9 +26,8 @@ OffscreenWindowLayer::OffscreenWindowLayer(ServerBitmap* bitmap,
 	  fBitmap(bitmap),
 	  fHWInterface(new BitmapHWInterface(fBitmap))
 {
+	fHWInterface->Initialize();
 	GetDrawingEngine()->SetHWInterface(fHWInterface);
-	GetDrawingEngine()->Initialize();
-	GetDrawingEngine()->Update();
 
 	fVisibleRegion.Set(fFrame);
 	fVisibleContentRegion.Set(fFrame);
@@ -42,7 +41,6 @@ OffscreenWindowLayer::~OffscreenWindowLayer()
 {
 	fHWInterface->WriteLock();
 	// Unlike normal Layers, we own the DrawingEngine instance
-	GetDrawingEngine()->Shutdown();
 	delete GetDrawingEngine();
 	fHWInterface->Shutdown();
 	fHWInterface->WriteUnlock();
diff --git a/src/servers/app/ScreenManager.cpp b/src/servers/app/ScreenManager.cpp
index ba80d2f30d..fb504a9e61 100644
--- a/src/servers/app/ScreenManager.cpp
+++ b/src/servers/app/ScreenManager.cpp
@@ -10,6 +10,8 @@
 
 
 #include "ScreenManager.h"
+
+#include "ServerConfig.h"
 #include "ServerScreen.h"
 
 #include <Autolock.h>
diff --git a/src/servers/app/ServerConfig.h b/src/servers/app/ServerConfig.h
index 35b4688a99..480d90eedb 100644
--- a/src/servers/app/ServerConfig.h
+++ b/src/servers/app/ServerConfig.h
@@ -8,17 +8,10 @@
 	#define TEST_MODE 0
 #endif
 
-// Uncomment this if the DisplayDriver should only rely on drawing functions implemented
-// in software even though hardware-accelerated functions are available
-// NOTE: everything is software right now (since DisplayDriverPainter)
-//#define DISABLE_HARDWARE_ACCELERATION
-
-// Define this for a quick hack to test some of the drawing functions
-//#define DISPLAYDRIVER_TEST_HACK
-
 // Define this if you want the display driver to emulate the input server.
 #if TEST_MODE
 #	define ENABLE_INPUT_SERVER_EMULATION
+//#	define USE_DIRECT_WINDOW_TEST_MODE
 #endif
 
 // This is the application signature of our app_server when running as a
diff --git a/src/servers/app/ServerScreen.cpp b/src/servers/app/ServerScreen.cpp
index bfb5e82aa7..2dbbbd0d31 100644
--- a/src/servers/app/ServerScreen.cpp
+++ b/src/servers/app/ServerScreen.cpp
@@ -67,9 +67,9 @@ Screen::~Screen()
 status_t
 Screen::Initialize()
 {
-	if (fDriver) {
-		// this will also init the graphics hardware the driver is attached to
-		return fDriver->Initialize();
+	if (fHWInterface) {
+		// init the graphics hardware
+		return fHWInterface->Initialize();
 	}
 
 	return B_NO_INIT;
@@ -79,8 +79,8 @@ Screen::Initialize()
 void
 Screen::Shutdown()
 {
-	if (fDriver)
-		fDriver->Shutdown();
+	if (fHWInterface)
+		fHWInterface->Shutdown();
 }
 
 
@@ -88,12 +88,10 @@ status_t
 Screen::SetMode(display_mode mode, bool makeDefault)
 {
 	status_t status = fHWInterface->SetMode(mode);
+		// any attached DrawingEngines will be notified
 
-	// the DrawingEngine needs to adjust itself
-	if (status >= B_OK) {
-		fDriver->Update();
+	if (status >= B_OK)
 		fIsDefault = makeDefault;
-	}
 
 	return status;
 }
diff --git a/src/servers/app/ViewLayer.cpp b/src/servers/app/ViewLayer.cpp
index 80f2e151a6..d82bd6209b 100644
--- a/src/servers/app/ViewLayer.cpp
+++ b/src/servers/app/ViewLayer.cpp
@@ -912,17 +912,18 @@ ViewLayer::ScrollBy(int32 x, int32 y, BRegion* dirtyRegion)
 
 	// remember old bounds for tracking dirty region
 	IntRect oldBounds(Bounds());
-	// find the area of the view that can be scrolled,
-	// contents are shifted in the opposite direction from scrolling
-	IntRect stillVisibleBounds(oldBounds);
-	stillVisibleBounds.OffsetBy(x, y);
 
 	// NOTE: using ConvertToVisibleInTopView()
 	// instead of ConvertToScreen(), this makes
 	// sure we don't try to move or invalidate an
 	// area hidden underneath the parent view
 	ConvertToVisibleInTopView(&oldBounds);
-	ConvertToVisibleInTopView(&stillVisibleBounds);
+
+	// find the area of the view that can be scrolled,
+	// contents are shifted in the opposite direction from scrolling
+	IntRect stillVisibleBounds(oldBounds);
+	stillVisibleBounds.OffsetBy(x, y);
+	stillVisibleBounds = stillVisibleBounds & oldBounds;
 
 	fScrollingOffset.x += x;
 	fScrollingOffset.y += y;
diff --git a/src/servers/app/drawing/AccelerantHWInterface.cpp b/src/servers/app/drawing/AccelerantHWInterface.cpp
index 2b2d477770..68a19aaf93 100644
--- a/src/servers/app/drawing/AccelerantHWInterface.cpp
+++ b/src/servers/app/drawing/AccelerantHWInterface.cpp
@@ -536,6 +536,8 @@ AccelerantHWInterface::SetMode(const display_mode& mode)
 	fAccScreenBlit = (screen_to_screen_blit)fAccelerantHook(B_SCREEN_TO_SCREEN_BLIT,
 		(void *)&fDisplayMode);
 
+	_NotifyFrameBufferChanged();
+
 	return status;
 }
 
@@ -580,6 +582,7 @@ AccelerantHWInterface::_UpdateFrameBufferConfig()
 	}
 
 	fFrontBuffer->SetFrameBufferConfig(fFrameBufferConfig);
+
 	return B_OK;
 }
 
diff --git a/src/servers/app/drawing/DWindowHWInterface.cpp b/src/servers/app/drawing/DWindowHWInterface.cpp
index 9b567cf1ba..e0dc284f68 100644
--- a/src/servers/app/drawing/DWindowHWInterface.cpp
+++ b/src/servers/app/drawing/DWindowHWInterface.cpp
@@ -599,6 +599,7 @@ DWindowHWInterface::_UpdateFrameBufferConfig()
 						fDisplayMode.virtual_width, 
 						fDisplayMode.virtual_height,
 						(color_space)fDisplayMode.space);
+
 	return B_OK;
 }
 
@@ -709,6 +710,7 @@ DWindowHWInterface::SetMode(const display_mode &mode)
 	}
 
 	_UpdateFrameBufferConfig();
+	_NotifyFrameBufferChanged();
 
 	return ret;
 }
diff --git a/src/servers/app/drawing/DrawingEngine.cpp b/src/servers/app/drawing/DrawingEngine.cpp
index 3bda7af338..e6e17f124d 100644
--- a/src/servers/app/drawing/DrawingEngine.cpp
+++ b/src/servers/app/drawing/DrawingEngine.cpp
@@ -13,7 +13,6 @@
 #include <algo.h>
 #include <stack.h>
 
-#include "HWInterface.h"
 #include "DrawState.h"
 #include "Painter.h"
 #include "PNGDump.h"
@@ -81,50 +80,37 @@ class FontLocker {
 //	#pragma mark -
 
 
-// constructor
 DrawingEngine::DrawingEngine(HWInterface* interface)
 	: fPainter(new Painter()),
-	  fGraphicsCard(interface),
+	  fGraphicsCard(NULL),
 	  fAvailableHWAccleration(0),
 	  fSuspendSyncLevel(0)
 {
+	SetHWInterface(interface);
 }
 
-// destructor
+
 DrawingEngine::~DrawingEngine()
 {
+	SetHWInterface(NULL);
 	delete fPainter;
 }
 
-// Initialize
-status_t
-DrawingEngine::Initialize()
+
+void
+DrawingEngine::FrameBufferChanged()
 {
-	status_t err = B_ERROR;
-	if (WriteLock()) {
-		err = fGraphicsCard->Initialize();
-		if (err < B_OK)
-			fprintf(stderr, "HWInterface::Initialize() failed: %s\n", strerror(err));
-		WriteUnlock();
+	if (!fGraphicsCard) {
+		fPainter->DetachFromBuffer();
+		fAvailableHWAccleration = 0;
+		return;
 	}
-	return err;
-}
 
-// Shutdown
-void
-DrawingEngine::Shutdown()
-{
-}
-
-// Update
-void
-DrawingEngine::Update()
-{
-	if (Lock()) {
+	if (WriteLock()) {
 		fPainter->AttachToBuffer(fGraphicsCard->DrawingBuffer());
 		// available HW acceleration might have changed
 		fAvailableHWAccleration = fGraphicsCard->AvailableHWAcceleration();
-		Unlock();
+		WriteUnlock();
 	}
 }
 
@@ -132,7 +118,18 @@ DrawingEngine::Update()
 void
 DrawingEngine::SetHWInterface(HWInterface* interface)
 {
+	if (fGraphicsCard == interface)
+		return;
+
+	if (fGraphicsCard)
+		fGraphicsCard->RemoveListener(this);
+
 	fGraphicsCard = interface;
+
+	if (fGraphicsCard)
+		fGraphicsCard->AddListener(this);
+
+	FrameBufferChanged();
 }
 
 // #pragma mark -
@@ -146,7 +143,7 @@ DrawingEngine::ConstrainClippingRegion(const BRegion* region)
 	fPainter->ConstrainClipping(region);
 }
 
-// SuspendAutoSync
+
 void
 DrawingEngine::SuspendAutoSync()
 {
@@ -155,7 +152,7 @@ DrawingEngine::SuspendAutoSync()
 	fSuspendSyncLevel++;
 }
 
-// Sync
+
 void
 DrawingEngine::Sync()
 {
diff --git a/src/servers/app/drawing/DrawingEngine.h b/src/servers/app/drawing/DrawingEngine.h
index 6c11636838..ec5e7cf779 100644
--- a/src/servers/app/drawing/DrawingEngine.h
+++ b/src/servers/app/drawing/DrawingEngine.h
@@ -16,12 +16,13 @@
 #include <Locker.h>
 #include <Point.h>
 
+#include "HWInterface.h"
+
 class BPoint;
 class BRect;
 class BRegion;
 
 class DrawState;
-class HWInterface;
 class Painter;
 class RGBColor;
 class ServerBitmap;
@@ -35,14 +36,13 @@ typedef struct {
 
 } LineArrayData;
 
-class DrawingEngine {
+class DrawingEngine : public HWInterfaceListener {
 public:
 							DrawingEngine(HWInterface* interface = NULL);
 	virtual					~DrawingEngine();
 
-			// when implementing, be sure to call the inherited version
-			status_t		Initialize();
-			void			Shutdown();
+	// HWInterfaceListener interface
+	virtual	void			FrameBufferChanged();
 
 			// locking
 			bool			Lock();
@@ -53,8 +53,6 @@ public:
 			void			WriteUnlock();
 
 			// for "changing" hardware
-			void			Update();
-
 			void			SetHWInterface(HWInterface* interface);
 
 			// for screen shots
@@ -133,7 +131,8 @@ public:
 
 			// -------- text related calls
 
-			// DrawState is NOT const because this call updates the pen position in the passed DrawState
+			// DrawState is NOT const because this call updates the
+			// pen position in the passed DrawState
 			BPoint			DrawString(const char* string, int32 length,
 								const BPoint& pt, DrawState* d,
 								escapement_delta* delta = NULL);
diff --git a/src/servers/app/drawing/HWInterface.cpp b/src/servers/app/drawing/HWInterface.cpp
index 052c132825..18b10dccf7 100644
--- a/src/servers/app/drawing/HWInterface.cpp
+++ b/src/servers/app/drawing/HWInterface.cpp
@@ -20,6 +20,12 @@
 #include <string.h>
 
 
+HWInterfaceListener::HWInterfaceListener()		{}
+HWInterfaceListener::~HWInterfaceListener()		{}
+
+
+// #pragma mark - HWInterface
+
 // constructor
 HWInterface::HWInterface(bool doubleBuffered)
 	: MultiLocker("hw interface lock"),
@@ -33,7 +39,8 @@ HWInterface::HWInterface(bool doubleBuffered)
 	  fCursorLocation(0, 0),
 	  fDoubleBuffered(doubleBuffered),
 //	  fUpdateExecutor(new UpdateQueue(this))
-	  fUpdateExecutor(NULL)
+	  fUpdateExecutor(NULL),
+	  fListeners(20)
 {
 }
 
@@ -303,6 +310,9 @@ HWInterface::CopyBackToFront(const BRect& frame)
 }
 
 
+// #pragma mark -
+
+
 overlay_token
 HWInterface::AcquireOverlayChannel()
 {
@@ -348,7 +358,9 @@ HWInterface::HideOverlay(Overlay* overlay)
 }
 
 
-// HideSoftwareCursor
+// #pragma mark -
+
+
 bool
 HWInterface::HideSoftwareCursor(const BRect& area)
 {
@@ -365,14 +377,14 @@ HWInterface::HideSoftwareCursor(const BRect& area)
 	return false;
 }
 
-// HideSoftwareCursor
+
 void
 HWInterface::HideSoftwareCursor()
 {
 	_RestoreCursorArea();
 }
 
-// ShowSoftwareCursor
+
 void
 HWInterface::ShowSoftwareCursor()
 {
@@ -382,6 +394,27 @@ HWInterface::ShowSoftwareCursor()
 }
 
 
+// #pragma mark -
+
+
+bool
+HWInterface::AddListener(HWInterfaceListener* listener)
+{
+	if (listener && !fListeners.HasItem(listener))
+		return fListeners.AddItem(listener);
+	return false;
+}
+
+
+void
+HWInterface::RemoveListener(HWInterfaceListener* listener)
+{
+	fListeners.RemoveItem(listener);
+}
+
+
+// #pragma mark -
+
 // _DrawCursor
 // * default implementation, can be used as fallback or for
 //   software cursor
@@ -843,5 +876,15 @@ HWInterface::_AdoptDragBitmap(const ServerBitmap* bitmap, const BPoint& offset)
 }
 
 
-
+void
+HWInterface::_NotifyFrameBufferChanged()
+{
+	BList listeners(fListeners);
+	int32 count = listeners.CountItems();
+	for (int32 i = 0; i < count; i++) {
+		HWInterfaceListener* listener
+			= (HWInterfaceListener*)listeners.ItemAtFast(i);
+		listener->FrameBufferChanged();
+	}
+}
 
diff --git a/src/servers/app/drawing/HWInterface.h b/src/servers/app/drawing/HWInterface.h
index 344c610cc0..b0e16daa50 100644
--- a/src/servers/app/drawing/HWInterface.h
+++ b/src/servers/app/drawing/HWInterface.h
@@ -15,6 +15,7 @@
 
 #include <Accelerant.h>
 #include <GraphicsCard.h>
+#include <List.h>
 #include <OS.h>
 #include <Region.h>
 
@@ -33,6 +34,14 @@ enum {
 	HW_ACC_INVERT_REGION				= 0x00000004,
 };
 
+class HWInterfaceListener {
+ public:
+								HWInterfaceListener();
+	virtual						~HWInterfaceListener();
+
+	virtual	void				FrameBufferChanged() = 0;
+};
+
 class HWInterface : public MultiLocker {
  public:
 								HWInterface(bool doubleBuffered = false);
@@ -139,6 +148,10 @@ class HWInterface : public MultiLocker {
 			void				HideSoftwareCursor();
 			void				ShowSoftwareCursor();
 
+	// Listener support
+			bool				AddListener(HWInterfaceListener* listener);
+			void				RemoveListener(HWInterfaceListener* listener);
+
  protected:
 	// implement this in derived classes
 	virtual	void				_DrawCursor(BRect area) const;
@@ -153,6 +166,8 @@ class HWInterface : public MultiLocker {
 			void				_AdoptDragBitmap(const ServerBitmap* bitmap,
 												 const BPoint& offset);
 
+			void				_NotifyFrameBufferChanged();
+
 			// If we draw the cursor somewhere in the drawing buffer,
 			// we need to backup its contents before drawing, so that
 			// we can restore that area when the cursor needs to be
@@ -197,6 +212,8 @@ class HWInterface : public MultiLocker {
 
  private:
 			UpdateQueue*		fUpdateExecutor;
+
+			BList				fListeners;
 };
 
 #endif // HW_INTERFACE_H
diff --git a/src/servers/app/drawing/ViewHWInterface.cpp b/src/servers/app/drawing/ViewHWInterface.cpp
index 43e6c703d9..55abfa9382 100644
--- a/src/servers/app/drawing/ViewHWInterface.cpp
+++ b/src/servers/app/drawing/ViewHWInterface.cpp
@@ -540,6 +540,8 @@ ViewHWInterface::SetMode(const display_mode &mode)
 			}
 		}
 
+		_NotifyFrameBufferChanged();
+
 		if (ret >= B_OK) {
 			// clear out buffers, alpha is 255 this way
 			// TODO: maybe this should handle different color spaces in different ways