diff -urN step3/group/S60test.mmp step4/group/S60test.mmp
--- step3/group/S60test.mmp	2004-06-19 21:12:32.000000000 +0200
+++ step4/group/S60test.mmp	2004-06-19 20:27:56.000000000 +0200
@@ -1,7 +1,7 @@
-TARGET            Step3.app
+TARGET            Step4.app
 TARGETTYPE        app
-UID               0x100039CE 0x04545FF3
-TARGETPATH        \system\apps\Step3
+UID               0x100039CE 0x04545FF4
+TARGETPATH        \system\apps\Step4
 LANG              SC
 
 SOURCEPATH        ..\src
@@ -10,11 +10,12 @@
 SOURCE            S60TestAppView.cpp
 SOURCE            S60TestAppUi.cpp
 SOURCE            S60TestDocument.cpp
+SOURCE            S60TestEngine.cpp
 SOURCE            Block.cpp
 SOURCE            Grid.cpp 
 
 SOURCEPATH        ..\group
-RESOURCE          Step3.rss
+RESOURCE          Step4.rss
 
 USERINCLUDE       ..\inc 
 
diff -urN step3/group/Step4.rss step4/group/Step4.rss
--- step3/group/Step4.rss	2004-06-19 20:58:42.000000000 +0200
+++ step4/group/Step4.rss	2004-06-19 20:46:58.000000000 +0200
@@ -72,3 +72,9 @@
    MENU_ITEM {command = EAknSoftkeyExit;   txt = "Exit";}
  };
 }
+
+RESOURCE TBUF32 r_note_game_over
+{
+    buf = "Game Over";
+}
+
diff -urN step3/inc/s60testappui.h step4/inc/s60testappui.h
--- step3/inc/s60testappui.h	2004-06-19 21:06:08.000000000 +0200
+++ step4/inc/s60testappui.h	2004-06-19 20:29:04.000000000 +0200
@@ -2,6 +2,7 @@
 #define __S60TEST_APPUI_H__
 
 #include <aknappui.h>
+#include "s60testengine.h"
 
 class CS60TestDocument;
 
@@ -22,6 +23,7 @@
     TEventCode /*aType*/);
 
 private:
+  CS60TestEngine *iEngine;
   CS60TestAppView *iAppView;
   CS60TestDocument *iDoc;
 };
diff -urN step3/inc/s60testappview.h step4/inc/s60testappview.h
--- step3/inc/s60testappview.h	2004-06-20 10:12:48.000000000 +0200
+++ step4/inc/s60testappview.h	2004-06-20 10:31:56.000000000 +0200
@@ -5,12 +5,13 @@
 #include <coecntrl.h>
 
 class CS60TestDocument;
+class CS60TestEngine;
 
 class CS60TestAppView : public CCoeControl
 {
 public:
-  static CS60TestAppView* NewL(const TRect& aRect, CS60TestDocument *aDoc);
-  static CS60TestAppView* NewLC(const TRect& aRect, CS60TestDocument *aDoc);
+  static CS60TestAppView* NewL(const TRect& aRect, CS60TestDocument *aDoc, CS60TestEngine *aEngine);
+  static CS60TestAppView* NewLC(const TRect& aRect, CS60TestDocument *aDoc, CS60TestEngine *aEngine);
   ~CS60TestAppView();
 
   static const TUint32 KColors[10];
@@ -20,8 +21,9 @@
 
 private:
   void ConstructL(const TRect& aRect);
-  CS60TestAppView(CS60TestDocument *aDoc);
+  CS60TestAppView(CS60TestDocument *aDoc, CS60TestEngine *aEngine);
   CS60TestDocument *iDoc;
+  CS60TestEngine *iEngine;
 };
 
 
diff -urN step3/inc/s60testdocument.h step4/inc/s60testdocument.h
--- step3/inc/s60testdocument.h	2004-06-19 21:23:20.000000000 +0200
+++ step4/inc/s60testdocument.h	2004-06-20 10:30:30.000000000 +0200
@@ -19,6 +19,7 @@
   static CS60TestDocument* NewLC(CEikApplication& aApp);
   ~CS60TestDocument();
   void GetRowContent(int nr, TFixedArray<TInt8, KGridX> &row) const;
+  int CheckRows();
   void NewBlock();
   void Reset();
   bool IsBlock(const TPoint &p) const;
@@ -29,6 +30,9 @@
   TGrid iGrid;
   TBlock iCurrBlock;
   TPoint iBlockPos;
+  TInt32 iScore;
+  TInt16 iLines;
+  TInt16 iLevel;
   CS60TestAppUi *iAppUi;
   TInt64 seed;
 
diff -urN step3/inc/s60testengine.h step4/inc/s60testengine.h
--- step3/inc/s60testengine.h	1970-01-01 01:00:00.000000000 +0100
+++ step4/inc/s60testengine.h	2004-06-21 18:55:36.000000000 +0200
@@ -0,0 +1,42 @@
+#ifndef S60TESTENGINE
+#define S60TESTENGINE
+
+#include "e32base.h"
+
+class CS60TestDocument;
+
+class CS60TestEngine : public CTimer
+{
+public:
+  static CS60TestEngine* NewLC(CS60TestDocument *aDoc);
+  static CS60TestEngine* NewL(CS60TestDocument *aDoc);
+
+  void KeyLeft();
+  void KeyRight();
+  void KeyRotate(int dir);
+  void KeyDrop();
+
+  void Reset();
+
+  int iInterval;
+  TTime iBeginTime;
+  TTime iPauseTime;
+
+  enum TEngineState
+  {
+    EGameOver=0,
+    EPaused,
+    ERunning
+  };
+  TEngineState iState;
+
+protected:
+  CS60TestDocument *iDoc;
+
+  CS60TestEngine(CS60TestDocument *aDoc)
+  :CTimer(EPriorityStandard), iInterval(500000), iDoc(aDoc) { }
+  void RunL();
+  void ConstructL();
+};
+
+#endif
diff -urN step3/src/s60testapplication.cpp step4/src/s60testapplication.cpp
--- step3/src/s60testapplication.cpp	2004-06-20 10:13:08.000000000 +0200
+++ step4/src/s60testapplication.cpp	2004-06-20 10:31:26.000000000 +0200
@@ -2,7 +2,7 @@
 #include "S60TestApplication.h"
 
 // UID for the application, this should correspond to the uid defined in the mmp file
-static const TUid KUidS60TestApp = {0x04545FF3};
+static const TUid KUidS60TestApp = {0x04545FF4};
 
 CApaDocument* CS60TestApplication::CreateDocumentL()
 {  
diff -urN step3/src/s60testappui.cpp step4/src/s60testappui.cpp
--- step3/src/s60testappui.cpp	2004-06-19 21:17:30.000000000 +0200
+++ step4/src/s60testappui.cpp	2004-06-20 10:28:08.000000000 +0200
@@ -12,11 +12,13 @@
 {
   BaseConstructL();
 
-  iAppView=CS60TestAppView::NewL(ClientRect(), iDoc);
+  iEngine=CS60TestEngine::NewL(iDoc);
+  iAppView=CS60TestAppView::NewL(ClientRect(), iDoc, iEngine);
   AddToStackL(iAppView);
 }
 
 CS60TestAppUi::CS60TestAppUi(CS60TestDocument *aDoc)
+:iEngine(NULL)
 {
   iDoc=aDoc;
 }
@@ -29,6 +31,7 @@
     delete iAppView;
     iAppView = NULL;
   }
+  delete iEngine;
 }
 
 void CS60TestAppUi::UpdateBoard()
@@ -48,6 +51,7 @@
 
     case ES60TestNewGame:
       iDoc->Reset();
+      iEngine->Reset();
       UpdateBoard();
       break;
 
@@ -63,29 +67,22 @@
   if (aType==EEventKey)
   {
     if (aKeyEvent.iCode==EKeyUpArrow)
-      if (iDoc->iBlockPos.iY>0)
-        iDoc->MoveBlock(iDoc->iBlockPos-TPoint(0, 1));
+      iEngine->KeyRotate(1);
 
     if (aKeyEvent.iCode==EKeyDownArrow)
-      iDoc->MoveBlock(iDoc->iBlockPos+TPoint(0, 1));
+      iEngine->KeyDrop();
 
     if (aKeyEvent.iCode==EKeyLeftArrow)
-      iDoc->MoveBlock(iDoc->iBlockPos-TPoint(1, 0));
+      iEngine->KeyLeft();
 
     if (aKeyEvent.iCode==EKeyRightArrow)
-      iDoc->MoveBlock(iDoc->iBlockPos+TPoint(1, 0));
-
-    if (aKeyEvent.iCode==EKeyDevice3)
-    {
-      if (iDoc->FixBlock())
-        iDoc->NewBlock();
-    }
+      iEngine->KeyRight();
 
     if (aKeyEvent.iCode=='1')
-      iDoc->RotateBlock(-1);
+      iEngine->KeyRotate(-1);
 
     if (aKeyEvent.iCode=='0' || aKeyEvent.iCode=='3')
-      iDoc->RotateBlock(1);
+      iEngine->KeyRotate(1);
   }
   return EKeyWasNotConsumed;
 }
diff -urN step3/src/s60testappview.cpp step4/src/s60testappview.cpp
--- step3/src/s60testappview.cpp	2004-06-19 21:19:30.000000000 +0200
+++ step4/src/s60testappview.cpp	2004-06-20 16:23:20.000000000 +0200
@@ -3,29 +3,31 @@
 
 #include "S60TestAppView.h"
 #include "S60TestDocument.h"
+#include "S60TestEngine.h"
 
 const TUint32 CS60TestAppView::KColors[10]=
   {0xffffff, 0xff0000, 0x00ff00, 0x0000ff, 0xff00ff,
    0xcc00dd, 0xadbeef, 0x000000, 0xffff00, 0xaaaaaa};
 
-CS60TestAppView *CS60TestAppView::NewL(const TRect& aRect, CS60TestDocument *aDoc)
+CS60TestAppView *CS60TestAppView::NewL(const TRect& aRect, CS60TestDocument *aDoc, CS60TestEngine *aEngine)
 {
-  CS60TestAppView *self=CS60TestAppView::NewLC(aRect, aDoc);
+  CS60TestAppView *self=CS60TestAppView::NewLC(aRect, aDoc, aEngine);
   CleanupStack::Pop(self);
   return self;
 }
 
-CS60TestAppView* CS60TestAppView::NewLC(const TRect& aRect, CS60TestDocument *aDoc)
+CS60TestAppView* CS60TestAppView::NewLC(const TRect& aRect, CS60TestDocument *aDoc, CS60TestEngine *aEngine)
 {
-  CS60TestAppView *self=new(ELeave) CS60TestAppView(aDoc);
+  CS60TestAppView *self=new(ELeave) CS60TestAppView(aDoc, aEngine);
   CleanupStack::PushL(self);
   self->ConstructL(aRect);
   return self;
 }
 
-CS60TestAppView::CS60TestAppView(CS60TestDocument *aDoc)
+CS60TestAppView::CS60TestAppView(CS60TestDocument *aDoc, CS60TestEngine *aEngine)
 {
   iDoc=aDoc;
+  iEngine=aEngine;
 }
 
 CS60TestAppView::~CS60TestAppView()
diff -urN step3/src/s60testdocument.cpp step4/src/s60testdocument.cpp
--- step3/src/s60testdocument.cpp	2004-06-19 21:20:32.000000000 +0200
+++ step4/src/s60testdocument.cpp	2004-06-20 10:27:38.000000000 +0200
@@ -41,6 +41,9 @@
 {
   iGrid.Clear();
   iBlockPos=TPoint(3, -4);
+  iScore=0;
+  iLines=0;
+  iLevel=1;
   iCurrBlock=TBlock::RandomBlock(seed);
 }
 
@@ -70,6 +73,38 @@
   return true;
 }
 
+int CS60TestDocument::CheckRows()
+{
+  int offset=0, i, j;
+  for (i=KGridY-1; i>=0; i--)
+  {
+    if (iGrid.iMask[i]==0xffffU)
+    {
+      offset++;
+      iScore++;
+      iLines++;
+      continue;
+    }
+
+    if (offset>0)
+    {
+      iGrid.iMask[i+offset]=iGrid.iMask[i];
+      for (j=0; j<KGridX; j++)
+        iGrid.iContent[i+offset][j]=iGrid.iContent[i][j];
+    }
+  }
+
+  for (i=0; i<offset; i++)
+  {
+    iGrid.iMask[i]=0x003f;
+    for (j=0; j<KGridX; j++)
+      iGrid.iContent[i][j]=0;
+  }
+
+  if (offset>0) iAppUi->UpdateBoard();
+  return offset;
+}
+
 bool CS60TestDocument::RotateBlock(int dir)
 {
   iCurrBlock.Rotate(dir);
diff -urN step3/src/s60testengine.cpp step4/src/s60testengine.cpp
--- step3/src/s60testengine.cpp	1970-01-01 01:00:00.000000000 +0100
+++ step4/src/s60testengine.cpp	2004-06-21 18:56:10.000000000 +0200
@@ -0,0 +1,91 @@
+#include <aknnotewrappers.h>
+#include <e32def.h>
+
+#include "s60testdocument.h"
+#include "s60testengine.h"
+#include "s60test.pan"
+#include "step4.rsg"
+
+CS60TestEngine *CS60TestEngine::NewLC(CS60TestDocument *aDoc)
+{
+  CS60TestEngine *self=new(ELeave) CS60TestEngine(aDoc);
+  CleanupStack::PushL(self);
+  self->ConstructL();
+  return self;
+}
+
+CS60TestEngine *CS60TestEngine::NewL(CS60TestDocument *aDoc)
+{
+  CS60TestEngine *self=CS60TestEngine::NewLC(aDoc);
+  CleanupStack::Pop(self);
+  return self;
+}
+
+
+void CS60TestEngine::ConstructL()
+{
+  CTimer::ConstructL();
+  CActiveScheduler::Add(this);
+  After(iInterval);
+  iState=ERunning;
+}
+
+void CS60TestEngine::KeyLeft()
+{
+  iDoc->MoveBlock(iDoc->iBlockPos-TPoint(1, 0));
+}
+
+void CS60TestEngine::KeyRight()
+{
+  iDoc->MoveBlock(iDoc->iBlockPos+TPoint(1, 0));
+}
+
+void CS60TestEngine::KeyDrop()
+{
+  while (iDoc->MoveBlock(iDoc->iBlockPos+TPoint(0, 1)))
+    ;
+}
+
+void CS60TestEngine::KeyRotate(int dir)
+{
+  iDoc->RotateBlock(dir);
+}
+
+void CS60TestEngine::Reset()
+{
+  if (iState==ERunning)
+    Cancel();
+  iState=ERunning;
+  After(iInterval);
+}
+
+void CS60TestEngine::RunL()
+{
+  if (!iDoc->MoveBlock(iDoc->iBlockPos+TPoint(0, 1)))
+  {
+    if (!iDoc->FixBlock())
+    {
+      // Game over
+      TBuf<64> message;
+      CEikonEnv::Static()->ReadResource(message, R_NOTE_GAME_OVER);
+      CAknInformationNote *informationNote=new(ELeave) CAknInformationNote;
+      informationNote->ExecuteLD(message);
+      iState=EGameOver;
+      return;
+    }
+    iDoc->CheckRows();
+
+    if (iDoc->iLevel<=(iDoc->iLines/10))
+    {
+      iInterval*=3;
+      iInterval/=4;
+      iDoc->iLevel++;
+    }
+
+    iDoc->NewBlock();
+  }
+
+  iBeginTime.HomeTime();
+  After(iInterval);
+}
+