Cosmetic changes.

Implemented video scanner and floating bus.

--HG--
extra : convert_revision : svn%3Affd33b8c-2492-42e0-bdc5-587b920b7d6d/trunk%4035682

Library/DirectSoundInterop.cs

@@ -9,42 +9,18 @@ namespace Jellyfish.Library
     public sealed partial class DirectSound
     {
         [Flags]
-        private enum BufferCapabilities
+        private enum BufferCapabilities { PrimaryBuffer = 0x00000001, CtrlPositionNotify = 0x00000100, StickyFocus = 0x00004000, GlobalFocus = 0x00008000 }
-        {
-            PrimaryBuffer = 0x00000001, 
-            CtrlPositionNotify = 0x00000100, 
-            StickyFocus = 0x00004000, 
-            GlobalFocus = 0x00008000
-        }
 
         [Flags]
-        private enum BufferLock
+        private enum BufferLock { None = 0x00000000, FromWriteCursor = 0x00000001, EntireBuffer = 0x00000002 }
-        {
-            None = 0x00000000, 
-            FromWriteCursor = 0x00000001, 
-            EntireBuffer = 0x00000002
-        }
 
         [Flags]
-        private enum BufferPlay
+        private enum BufferPlay { Looping = 0x00000001 }
-        {
-            Looping = 0x00000001
-        }
 
         [Flags]
-        private enum BufferStatus
+        private enum BufferStatus { Playing = 0x00000001, BufferLost = 0x00000002, Looping = 0x00000004, Terminated = 0x00000020 }
-        {
-            Playing = 0x00000001, 
-            BufferLost = 0x00000002, 
-            Looping = 0x00000004, 
-            Terminated = 0x00000020
-        }
 
-        private enum CooperativeLevel
+        private enum CooperativeLevel { Normal = 1, Priority = 2 }
-        {
-            Normal = 1, 
-            Priority = 2
-        }
 
         [StructLayout(LayoutKind.Sequential)]
         private sealed class BufferDescription

Library/Silverlight/ApplicationBase.cs

@@ -10,16 +10,16 @@ public ApplicationBase(string name)
         {
             Name = name;
 
-            UnhandledException += Application_UnhandledException;
+            UnhandledException += OnApplicationUnhandledException;
-            //AppDomain.CurrentDomain.UnhandledException += AppDomain_UnhandledException;
+            //AppDomain.CurrentDomain.UnhandledException += OnAppDomainUnhandledException;
         }
 
-        private void Application_UnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
+        private void OnApplicationUnhandledException(object sender, ApplicationUnhandledExceptionEventArgs e)
         {
             MessageBox.Show(GetExceptionMessage(e.ExceptionObject), GetExceptionCaption("Application Exception", false), MessageBoxButton.OK);
         }
 
-        //private void AppDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
+        //private void OnAppDomainUnhandledException(object sender, UnhandledExceptionEventArgs e)
         //{
         //    MessageBox.Show(GetExceptionMessage(e.ExceptionObject as Exception), GetExceptionCaption("AppDomain Exception", e.IsTerminating), MessageBoxButton.OK);
         //}

Library/Silverlight/FrameRateCounter.xaml.cs

@@ -11,10 +11,10 @@ public FrameRateCounter()
         {
             InitializeComponent();
 
-            CompositionTarget.Rendering += CompositionTarget_Rendering;
+            CompositionTarget.Rendering += OnCompositionTargetRendering;
         }
 
-        private void CompositionTarget_Rendering(object sender, EventArgs e)
+        private void OnCompositionTargetRendering(object sender, EventArgs e)
         {
             _frameCount++;
 

Library/Wpf/ApplicationBase.cs

@@ -14,18 +14,18 @@ public ApplicationBase(string name)
         {
             Name = name;
 
-            DispatcherUnhandledException += Application_DispatcherUnhandledException;
+            DispatcherUnhandledException += OnApplicationDispatcherUnhandledException;
-            AppDomain.CurrentDomain.UnhandledException += AppDomain_UnhandledException;
+            AppDomain.CurrentDomain.UnhandledException += OnAppDomainUnhandledException;
         }
 
-        private void Application_DispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
+        private void OnApplicationDispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
         {
             MessageBox.Show(GetExceptionMessage(e.Exception), GetExceptionCaption("Application Dispatcher Exception", true));
             Shutdown();
             e.Handled = true;
         }
 
-        private void AppDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
+        private void OnAppDomainUnhandledException(object sender, UnhandledExceptionEventArgs e)
         {
             MessageBox.Show(GetExceptionMessage(e.ExceptionObject as Exception), GetExceptionCaption("AppDomain Exception", e.IsTerminating));
         }

Library/Wpf/FrameRateCounter.xaml.cs

@@ -11,10 +11,10 @@ public FrameRateCounter()
         {
             InitializeComponent();
 
-            CompositionTarget.Rendering += CompositionTarget_Rendering;
+            CompositionTarget.Rendering += OnCompositionTargetRendering;
         }
 
-        private void CompositionTarget_Rendering(object sender, EventArgs e)
+        private void OnCompositionTargetRendering(object sender, EventArgs e)
         {
             _frameCount++;
 

Virtu/Cpu.cs

@@ -10,8 +10,6 @@ public sealed partial class Cpu : MachineComponent
         public Cpu(Machine machine) : 
             base(machine)
         {
-            _updateEvent = UpdateEvent; // cache delegate; avoids garbage
-
             ExecuteOpcode65N02 = new Action[OpcodeCount]
             {
                 Execute65X02Brk00, Execute65X02Ora01, Execute65N02Nop02, Execute65N02Nop03, 
@@ -157,7 +155,7 @@ public override void Initialize()
 
             UpdateSettings();
 
-            Machine.Events.AddEvent(CyclesPerUpdate, _updateEvent);
+            Machine.Video.VSync += OnVideoVSync;
         }
 
         public override void Reset()
@@ -3212,21 +3210,20 @@ private void Execute65C02Tsb0C() // tsb abs
         }
         #endregion
 
-        private void UpdateEvent()
+        private void OnVideoVSync(object sender, EventArgs e)
         {
             UpdateSettings();
 
             if (Machine.Settings.Cpu.IsThrottled)
             {
                 long elapsedTime = DateTime.UtcNow.Ticks - _lastTime;
-                if (elapsedTime < TicksPerVSync)
+                long ticksPerVSync = Machine.Video.TicksPerVSync;
+                if (elapsedTime < ticksPerVSync)
                 {
-                    Thread.Sleep(TimeSpan.FromTicks(TicksPerVSync - elapsedTime).Milliseconds);
+                    Thread.Sleep(TimeSpan.FromTicks(ticksPerVSync - elapsedTime).Milliseconds);
                 }
                 _lastTime = DateTime.UtcNow.Ticks;
             }
-
-            Machine.Events.AddEvent(CyclesPerUpdate, _updateEvent);
         }
 
         private void UpdateSettings()
@@ -3245,8 +3242,6 @@ private void UpdateSettings()
         public int Opcode { get; private set; }
         public long Cycles { get; private set; }
 
-        private Action _updateEvent;
-
         private Memory _memory;
 
         private Action[] _executeOpcode;

Virtu/CpuData.cs

@@ -4,11 +4,6 @@ namespace Jellyfish.Virtu
 {
     public partial class Cpu
     {
-        private const int CyclesPerUpdate = 17030;
-        private const int CyclesPerVSync = 17030;
-        private const int CyclesPerSecond = 1022730;
-        private static readonly long TicksPerVSync = TimeSpan.FromSeconds((double)CyclesPerVSync / CyclesPerSecond).Ticks;
-
         private const int OpcodeCount = 256;
 
         private readonly Action[] ExecuteOpcode65N02;

Virtu/Jellyfish.Virtu.FxCop

@@ -96,19 +96,6 @@
            </Member>
           </Members>
          </Type>
-         <Type Name="Video">
-          <Members>
-           <Member Name="#ReadFloatingBus()">
-            <Messages>
-             <Message TypeName="MarkMembersAsStatic" Category="Microsoft.Performance" CheckId="CA1822" Created="2009-12-11 09:07:49Z" FixCategory="DependsOnFix">
-              <Issue>
-               <Item>'Video.ReadFloatingBus()'</Item>
-              </Issue>
-             </Message>
-            </Messages>
-           </Member>
-          </Members>
-         </Type>
         </Types>
        </Namespace>
       </Namespaces>
@@ -153,19 +140,6 @@
            </Member>
           </Members>
          </Type>
-         <Type Name="Video">
-          <Members>
-           <Member Name="#ReadFloatingBus()">
-            <Messages>
-             <Message TypeName="MarkMembersAsStatic" Category="Microsoft.Performance" CheckId="CA1822" Created="2009-04-13 00:02:55Z" FixCategory="DependsOnFix">
-              <Issue>
-               <Item>'Video.ReadFloatingBus()'</Item>
-              </Issue>
-             </Message>
-            </Messages>
-           </Member>
-          </Members>
-         </Type>
         </Types>
        </Namespace>
       </Namespaces>
@@ -180,9 +154,6 @@
    <Rule TypeName="DoNotRaiseReservedExceptionTypes" Category="Microsoft.Usage" CheckId="CA2201">
     <Resolution Name="TooGeneric">{0} creates an exception of type {1}, an exception type that is not sufficiently specific and should never be raised by user code. If this exception instance might be thrown, use a different exception type.</Resolution>
    </Rule>
-   <Rule TypeName="MarkMembersAsStatic" Category="Microsoft.Performance" CheckId="CA1822">
-    <Resolution Name="Default">The 'this' parameter (or 'Me' in Visual Basic) of {0} is never used. Mark the member as static (or Shared in Visual Basic) or use 'this'/'Me' in the method body or at least one property accessor, if appropriate.</Resolution>
-   </Rule>
    <Rule TypeName="RemoveUnusedLocals" Category="Microsoft.Performance" CheckId="CA1804">
     <Resolution Name="Default">{0} declares a variable, {1}, of type {2}, which is never used or is only assigned to. Use this variable or remove it.</Resolution>
    </Rule>

Virtu/Keyboard.cs

@@ -10,7 +10,6 @@ public sealed class Keyboard : MachineComponent
         public Keyboard(Machine machine) :
             base(machine)
         {
-            _pollEvent = PollEvent; // cache delegate; avoids garbage
         }
 
         public override void Initialize()
@@ -19,8 +18,7 @@ public override void Initialize()
             _gamePortService = Machine.Services.GetService<GamePortService>();
 
             _keyboardService.AsciiKeyDown += (sender, e) => Latch = e.AsciiKey;
-
+            Machine.Video.VSync += OnVideoVSync;
-            Machine.Events.AddEvent(CyclesPerPoll, _pollEvent);
         }
 
         [SuppressMessage("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity")]
@@ -123,7 +121,7 @@ public void ResetStrobe()
             Strobe = false;
         }
 
-        private void PollEvent()
+        private void OnVideoVSync(object sender, EventArgs e)
         {
             if (_keyboardService.IsResetKeyDown)
             {
@@ -145,8 +143,6 @@ private void PollEvent()
                 Machine.Video.ToggleMonochrome();
                 _keyboardService.WaitForKeyUp();
             }
-
-            Machine.Events.AddEvent(CyclesPerPoll, _pollEvent);
         }
 
         public bool IsAnyKeyDown { get { return _keyboardService.IsAnyKeyDown; } }
@@ -154,10 +150,6 @@ private void PollEvent()
 
         private int Latch { get { return _latch; } set { _latch = value; Strobe = true; } }
 
-        private const int CyclesPerPoll = 17030;
-
-        private Action _pollEvent;
-
         private KeyboardService _keyboardService;
         private GamePortService _gamePortService;
 

Virtu/Machine.cs

@@ -83,7 +83,7 @@ private void Run() // machine thread
             {
                 do
                 {
-                    Events.RaiseEvents(Cpu.Execute());
+                    Events.HandleEvents(Cpu.Execute());
                 }
                 while (State == MachineState.Running);
 

Virtu/MachineEvents.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 
 namespace Jellyfish.Virtu
@@ -78,8 +77,7 @@ public int FindEvent(Action action)
             return 0;
         }
 
-        [SuppressMessage("Microsoft.Design", "CA1030:UseEventsWhereAppropriate")]
+        public void HandleEvents(int delta)
-        public void RaiseEvents(int delta)
         {
             LinkedListNode<MachineEvent> node = _used.First;
             node.Value.Delta -= delta;

Virtu/MachineSettings.cs

@@ -38,7 +38,7 @@ public MachineSettings()
             };
             Video = new VideoSettings
             {
-                IsFullScreen = false, IsMonochrome = false, ScannerType = 0, 
+                IsFullScreen = false, IsMonochrome = false, ScannerModes = ScannerModes.None, 
                 Color = new ColorSettings
                 {
                     Black = 0x000000, 
@@ -172,8 +172,8 @@ public void Deserialize(Stream stream)
                     Video = new VideoSettings
                     {
                         IsFullScreen = (bool)video.Attribute("IsFullScreen"), 
-                        IsMonochrome = (bool)video.Attribute("IsMonochrome"), 
+                        IsMonochrome = (bool)video.Attribute("IsMonochrome"),
-                        ScannerType = (int)video.Attribute("ScannerType"), 
+                        ScannerModes = (ScannerModes)Enum.Parse(typeof(ScannerModes), (string)video.Attribute("ScannerModes"), true), 
                         Color = new ColorSettings
                         {
                             Black = (uint)color.Attribute("Black"), 
@@ -269,7 +269,7 @@ public void Serialize(Stream stream)
                 new XElement(ns + "Video",
                     new XAttribute("IsFullScreen", Video.IsFullScreen),
                     new XAttribute("IsMonochrome", Video.IsMonochrome),
-                    new XAttribute("ScannerType", Video.ScannerType),
+                    new XAttribute("ScannerModes", Video.ScannerModes),
                     new XElement(ns + "Color",
                         new XAttribute("Black", Video.Color.Black),
                         new XAttribute("DarkBlue", Video.Color.DarkBlue),
@@ -377,11 +377,14 @@ public sealed class ColorSettings
         public uint Monochrome { get; set; }
     }
 
+    [Flags]
+    public enum ScannerModes { None = 0x0, AppleII = 0x1, Pal = 0x2 } // defaults to AppleIIe, Ntsc
+
     public sealed class VideoSettings
     {
         public bool IsFullScreen { get; set; }
         public bool IsMonochrome { get; set; }
-        public int ScannerType { get; set; }
+        public ScannerModes ScannerModes { get; set; }
         public ColorSettings Color { get; set; }
     };
 }

Virtu/Services/KeyboardService.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 
 namespace Jellyfish.Virtu.Services
@@ -31,8 +30,7 @@ protected KeyboardService(Machine machine) :
 
         public abstract bool IsKeyDown(int key);
 
-        [SuppressMessage("Microsoft.Design", "CA1030:UseEventsWhereAppropriate")]
+        protected void OnAsciiKeyDown(int asciiKey)
-        protected void RaiseAsciiKeyDown(int asciiKey)
         {
             EventHandler<AsciiKeyEventArgs> handler = AsciiKeyDown;
             if (handler != null)

Virtu/Silverlight/MainPage.xaml.cs

@@ -26,11 +26,11 @@ public MainPage()
             _machine.Services.AddService(typeof(VideoService), _videoService);
 
             Loaded += (sender, e) => _machine.Start();
-            CompositionTarget.Rendering += CompositionTarget_Rendering;
+            CompositionTarget.Rendering += OnCompositionTargetRendering;
             Application.Current.Exit += (sender, e) => _machine.Stop();
 
-            _disk1Button.Click += (sender, e) => DiskButton_Click(0);
+            _disk1Button.Click += (sender, e) => OnDiskButtonClick(0);
-            _disk2Button.Click += (sender, e) => DiskButton_Click(1);
+            _disk2Button.Click += (sender, e) => OnDiskButtonClick(1);
         }
 
         public void Dispose()
@@ -43,14 +43,14 @@ public void Dispose()
             _videoService.Dispose();
         }
 
-        private void CompositionTarget_Rendering(object sender, EventArgs e)
+        private void OnCompositionTargetRendering(object sender, EventArgs e)
         {
             _keyboardService.Update();
             _gamePortService.Update();
             _videoService.Update();
         }
 
-        private void DiskButton_Click(int drive)
+        private void OnDiskButtonClick(int drive)
         {
             OpenFileDialog dialog = new OpenFileDialog();
             dialog.Filter = "Disk Files (*.dsk;*.nib)|*.dsk;*.nib|All Files (*.*)|*.*";

Virtu/Silverlight/Services/SilverlightKeyboardService.cs

@@ -19,9 +19,9 @@ public SilverlightKeyboardService(Machine machine, UserControl page) :
 
             _page = page;
 
-            _page.KeyDown += Page_KeyDown;
+            _page.KeyDown += OnPageKeyDown;
-            _page.KeyUp += Page_KeyUp;
+            _page.KeyUp += OnPageKeyUp;
-            _page.LostFocus += Page_LostFocus;
+            _page.LostFocus += OnPageLostFocus;
         }
 
         public override bool IsKeyDown(int key)
@@ -62,7 +62,7 @@ private bool IsKeyDown(Key key)
             return _states[(int)key];
         }
 
-        private void Page_KeyDown(object sender, KeyEventArgs e)
+        private void OnPageKeyDown(object sender, KeyEventArgs e)
         {
             _states[(int)e.Key] = true;
             IsAnyKeyDown = true;
@@ -70,19 +70,19 @@ private void Page_KeyDown(object sender, KeyEventArgs e)
             int asciiKey = GetAsciiKey(e.Key, e.PlatformKeyCode);
             if (asciiKey >= 0)
             {
-                RaiseAsciiKeyDown(asciiKey);
+                OnAsciiKeyDown(asciiKey);
                 e.Handled = true;
             }
         }
 
-        private void Page_KeyUp(object sender, KeyEventArgs e)
+        private void OnPageKeyUp(object sender, KeyEventArgs e)
         {
             _capsLock ^= (e.Key == Key.CapsLock); // SL is missing caps lock support; try to track manually
             _states[(int)e.Key] = false;
             _updateAnyKeyDown = true;
         }
 
-        private void Page_LostFocus(object sender, RoutedEventArgs e) // reset keyboard state on lost focus; can't access keyboard state on got focus
+        private void OnPageLostFocus(object sender, RoutedEventArgs e) // reset keyboard state on lost focus; can't access keyboard state on got focus
         {
             IsAnyKeyDown = false;
             foreach (Key key in KeyValues)

Virtu/Video.cs

@@ -29,9 +29,9 @@ public override void Initialize()
             UpdateSettings();
             IsVBlank = true;
 
-            Machine.Events.AddEvent((CyclesPerVBlank / 2), _leaveVBlankEvent);
+            Machine.Events.AddEvent(_cyclesPerVBlankPreset, _leaveVBlankEvent); // align flush events with scanner; assumes vcount preset at start of frame [3-15, 3-16]
-            Machine.Events.AddEvent(CyclesPerVSync, _resetVSyncEvent);
+            Machine.Events.AddEvent(_cyclesPerVSync, _resetVSyncEvent);
-            Machine.Events.AddEvent(CyclesPerFlash, _inverseTextEvent);
+            Machine.Events.AddEvent(_cyclesPerFlash, _inverseTextEvent);
         }
 
         public override void Reset()
@@ -92,8 +92,29 @@ public void DirtyScreenText()
 
         public int ReadFloatingBus()
         {
-            // TODO
+            // derive scanner counters from current cycles into frame; assumes hcount and vcount preset at start of frame [3-13, 3-15, 3-16]
-            return 0x00;
+            int cycles = _cyclesPerVSync - Machine.Events.FindEvent(_resetVSyncEvent);
+            int hClock = cycles % CyclesPerHSync;
+            int hCount = (hClock != 0) ? HCountPreset + hClock - 1 : 0;
+            int vLine = cycles / CyclesPerHSync;
+            int vCount = _vCountPreset + vLine;
+
+            // derive scanner address [5-8]
+            int address = ((vCount << 4) & 0x0380) | ((0x0068 + (hCount & 0x0038) + (((vCount >> 1) & 0x0060) | ((vCount >> 3) & 0x0018))) & 0x0078) | (hCount & 0x0007);
+            if (_memory.IsHires && !(_memory.IsMixed && ((vCount & 0xA0) == 0xA0))) // hires but not actively mixed [5-13, 5-19]
+            {
+                address |= (_memory.IsVideoPage2 ? 0x4000 : 0x2000) | ((vCount << 10) & 0x1C00);
+            }
+            else
+            {
+                address |= _memory.IsVideoPage2 ? 0x0800 : 0x0400;
+                if (((_scannerModes & ScannerModes.AppleII) != 0) && (hCount < HCountLeaveHBlank))
+                {
+                    address |= 0x1000;
+                }
+            }
+
+            return _memory.Read(address);
         }
 
         public void SetCharSet()
@@ -641,7 +662,7 @@ private void DrawDHiresM(int address, int x, int y)
         #region Flush Methods
         private void FlushRowMode0(int y)
         {
-            int address = (!_memory.IsVideoPage2 ? 0x0400 : 0x0800) + AddressOffset[y];
+            int address = (_memory.IsVideoPage2 ? 0x0800 : 0x0400) + AddressOffset[y];
             for (int x = 0; x < CellColumns; x++)
             {
                 if (_isCellDirty[CellColumns * y + x])
@@ -654,7 +675,7 @@ private void FlushRowMode0(int y)
 
         private void FlushRowMode1(int y)
         {
-            int address = (!_memory.IsVideoPage2 ? 0x0400 : 0x0800) + AddressOffset[y];
+            int address = (_memory.IsVideoPage2 ? 0x0800 : 0x0400) + AddressOffset[y];
             for (int x = 0; x < CellColumns; x++)
             {
                 if (_isCellDirty[CellColumns * y + x])
@@ -667,7 +688,7 @@ private void FlushRowMode1(int y)
 
         private void FlushRowMode2(int y)
         {
-            int address = (!_memory.IsVideoPage2 ? 0x0400 : 0x0800) + AddressOffset[y];
+            int address = (_memory.IsVideoPage2 ? 0x0800 : 0x0400) + AddressOffset[y];
             for (int x = 0; x < 2 * CellColumns; x += 2)
             {
                 if (_isCellDirty[CellColumns * y + x / 2])
@@ -705,7 +726,7 @@ private void FlushRowMode4(int y)
 
         private void FlushRowMode5(int y)
         {
-            int address = !_memory.IsVideoPage2 ? 0x2000 : 0x4000;
+            int address = _memory.IsVideoPage2 ? 0x4000 : 0x2000;
             for (int i = 0; i < CellHeight; i++, y++)
             {
                 for (int x = 0; x < CellColumns; x++)
@@ -745,7 +766,7 @@ private void FlushRowMode7(int y)
 
         private void FlushRowMode8(int y)
         {
-            int address = (!_memory.IsVideoPage2 ? 0x0400 : 0x0800) + AddressOffset[y];
+            int address = (_memory.IsVideoPage2 ? 0x0800 : 0x0400) + AddressOffset[y];
             for (int x = 0; x < CellColumns; x++)
             {
                 if (_isCellDirty[CellColumns * y + x])
@@ -758,7 +779,7 @@ private void FlushRowMode8(int y)
 
         private void FlushRowMode9(int y)
         {
-            int address = (!_memory.IsVideoPage2 ? 0x0400 : 0x0800) + AddressOffset[y];
+            int address = (_memory.IsVideoPage2 ? 0x0800 : 0x0400) + AddressOffset[y];
             for (int x = 0; x < 2 * CellColumns; x += 2)
             {
                 if (_isCellDirty[CellColumns * y + x / 2])
@@ -796,7 +817,7 @@ private void FlushRowModeB(int y)
 
         private void FlushRowModeC(int y)
         {
-            int address = !_memory.IsVideoPage2 ? 0x2000 : 0x4000;
+            int address = _memory.IsVideoPage2 ? 0x4000 : 0x2000;
             for (int i = 0; i < CellHeight; i++, y++)
             {
                 for (int x = 0; x < CellColumns; x++)
@@ -812,7 +833,7 @@ private void FlushRowModeC(int y)
 
         private void FlushRowModeD(int y)
         {
-            int address = !_memory.IsVideoPage2 ? 0x2000 : 0x4000;
+            int address = _memory.IsVideoPage2 ? 0x4000 : 0x2000;
             for (int i = 0; i < CellHeight; i++, y++)
             {
                 for (int x = 0; x < CellColumns; x++)
@@ -854,7 +875,7 @@ private void FlushRowModeF(int y)
 
         private void FlushRowEvent()
         {
-            int y = (CyclesPerVSync - (CyclesPerVBlank / 2) - Machine.Events.FindEvent(_resetVSyncEvent)) / CyclesPerHSync;
+            int y = (_cyclesPerVSync - _cyclesPerVBlankPreset - Machine.Events.FindEvent(_resetVSyncEvent)) / CyclesPerHSync;
 
             FlushRowMode[_memory.VideoMode](y - CellHeight); // in arrears
 
@@ -866,7 +887,7 @@ private void FlushRowEvent()
             {
                 IsVBlank = true;
 
-                Machine.Events.AddEvent(CyclesPerVBlank, _leaveVBlankEvent);
+                Machine.Events.AddEvent(_cyclesPerVBlank, _leaveVBlankEvent);
             }
         }
 
@@ -886,7 +907,7 @@ private void InverseTextEvent()
 
             DirtyScreenText();
 
-            Machine.Events.AddEvent(CyclesPerFlash, _inverseTextEvent);
+            Machine.Events.AddEvent(_cyclesPerFlash, _inverseTextEvent);
         }
 
         private void LeaveVBlankEvent()
@@ -900,7 +921,13 @@ private void ResetVSyncEvent()
         {
             UpdateSettings();
 
-            Machine.Events.AddEvent(CyclesPerVSync, _resetVSyncEvent);
+            EventHandler handler = VSync;
+            if (handler != null)
+            {
+                handler(this, EventArgs.Empty);
+            }
+
+            Machine.Events.AddEvent(_cyclesPerVSync, _resetVSyncEvent);
         }
 
         private void SetPixel(int x, int y, int color)
@@ -949,6 +976,23 @@ private void UpdateSettings()
             _colorPalette[ColorDHiresE] = settings.Color.Yellow;
             _colorPalette[ColorDHiresF] = settings.Color.White;
 
+            _scannerModes = settings.ScannerModes;
+            if ((_scannerModes & ScannerModes.Pal) != 0)
+            {
+                _vCountPreset = VCountPresetPal;
+                _vLineLeaveVBlank = VLineLeaveVBlankPal;
+            }
+            else
+            {
+                _vCountPreset = VCountPresetNtsc;
+                _vLineLeaveVBlank = VLineLeaveVBlankNtsc;
+            }
+
+            _cyclesPerVBlank = (_vLineLeaveVBlank - VLineEnterVBlank) * CyclesPerHSync;
+            _cyclesPerVBlankPreset = (_vLineLeaveVBlank - VLineTriggerPreset) * CyclesPerHSync; // cycles during vblank after vcount preset [3-15, 3-16]
+            _cyclesPerVSync = _vLineLeaveVBlank * CyclesPerHSync;
+            _cyclesPerFlash = VSyncsPerFlash * _cyclesPerVSync;
+
             if (_videoService.IsFullScreen != settings.IsFullScreen)
             {
                 _videoService.ToggleFullScreen();
@@ -956,6 +1000,9 @@ private void UpdateSettings()
         }
 
         public bool IsVBlank { get; private set; }
+        public long TicksPerVSync { get { return TimeSpan.FromSeconds((double)_cyclesPerVSync / CyclesPerSecond).Ticks; } }
+
+        public event EventHandler VSync;
 
         private Action _flushRowEvent;
         private Action _inverseTextEvent;
@@ -969,5 +1016,12 @@ private void UpdateSettings()
         private uint[] _colorPalette = new uint[ColorPaletteCount];
         private bool[] _isCellDirty = new bool[Height * CellColumns + 1]; // includes sentinel
         private bool _isTextInversed;
+        private int _cyclesPerVBlank;
+        private int _cyclesPerVBlankPreset;
+        private int _cyclesPerVSync;
+        private int _cyclesPerFlash;
+        private int _vCountPreset;
+        private int _vLineLeaveVBlank;
+        private ScannerModes _scannerModes;
     }
 }

Virtu/VideoData.cs

@@ -1596,9 +1596,17 @@ public partial class Video
         private const int CyclesPerHBlank = 25;
         private const int CyclesPerHSync = 65;
         private const int CyclesPerFlush = 8 * CyclesPerHSync;
-        private const int CyclesPerVBlank = 70 * CyclesPerHSync;
+        private const int CyclesPerSecond = 1022730;
-        private const int CyclesPerVSync = 262 * CyclesPerHSync;
+
-        private const int CyclesPerFlash = 16 * CyclesPerVSync;
+        private const int HCountPreset = 0x40; // hcount preset after hcount overflows -> HPE' low [3-13]
+        private const int HCountLeaveHBlank = 0x58; // hcount when leaving hblank [3-15]
+        private const int VCountPresetNtsc = 0xFA; // vcount preset after vcount overflows (NTSC) [3-13]
+        private const int VCountPresetPal = 0xC8; // vcount preset after vcount overflows (PAL) [3-17]
+        private const int VLineEnterVBlank = 192; // vline when entering vblank (NTSC & PAL) [3-17]
+        private const int VLineTriggerPreset = 256; // vline when vcount overflows and presets (NTSC & PAL) [3-15, 3-16]
+        private const int VLineLeaveVBlankNtsc = 262; // vline when leaving vblank (NTSC) [3-13]
+        private const int VLineLeaveVBlankPal = 312; // vline when leaving vblank (PAL) [3-17]
+        private const int VSyncsPerFlash = 16; // flash count using vcount overflow [3-17]
 
         public const int ModeCount = 16;
 
@@ -1622,7 +1630,7 @@ public partial class Video
         private readonly Action<int>[] FlushRowMode;
 
         private const int Width = 560;
-        private const int Height = 192;
+        private const int Height = VLineEnterVBlank;
 
         private const int TextHeight = 8;
         private const int TextRows = Height / TextHeight;

Virtu/Wpf/MainWindow.xaml.cs

@@ -26,11 +26,11 @@ public MainWindow()
             _machine.Services.AddService(typeof(VideoService), _videoService);
 
             Loaded += (sender, e) => _machine.Start();
-            CompositionTarget.Rendering += CompositionTarget_Rendering;
+            CompositionTarget.Rendering += OnCompositionTargetRendering;
             Application.Current.Exit += (sender, e) => _machine.Stop();
 
-            _disk1Button.Click += (sender, e) => DiskButton_Click(0);
+            _disk1Button.Click += (sender, e) => OnDiskButtonClick(0);
-            _disk2Button.Click += (sender, e) => DiskButton_Click(1);
+            _disk2Button.Click += (sender, e) => OnDiskButtonClick(1);
         }
 
         public void Dispose()
@@ -43,14 +43,14 @@ public void Dispose()
             _videoService.Dispose();
         }
 
-        private void CompositionTarget_Rendering(object sender, EventArgs e)
+        private void OnCompositionTargetRendering(object sender, EventArgs e)
         {
             _keyboardService.Update();
             _gamePortService.Update();
             _videoService.Update();
         }
 
-        private void DiskButton_Click(int drive)
+        private void OnDiskButtonClick(int drive)
         {
             OpenFileDialog dialog = new OpenFileDialog();
             dialog.Filter = "Disk Files (*.dsk;*.nib)|*.dsk;*.nib|All Files (*.*)|*.*";

Virtu/Wpf/Services/WpfAudioService.cs

@@ -18,7 +18,7 @@ public WpfAudioService(Machine machine, Window window) :
             _window = window;
 
             _window.SourceInitialized += (sender, e) => _directSound.Start(_window.GetHandle());
-            _directSound.Update += DirectSound_Update;
+            _directSound.Update += OnDirectSoundUpdate;
             _window.Closed += (sender, e) => _directSound.Stop();
         }
 
@@ -32,7 +32,7 @@ protected override void Dispose(bool disposing)
             base.Dispose(disposing);
         }
 
-        private void DirectSound_Update(object sender, DirectSoundUpdateEventArgs e)
+        private void OnDirectSoundUpdate(object sender, DirectSoundUpdateEventArgs e)
         {
             IntPtr buffer = e.Buffer;
             Update(e.BufferSize, (source, count) => 

Virtu/Wpf/Services/WpfKeyboardService.cs

@@ -18,8 +18,8 @@ public WpfKeyboardService(Machine machine, Window window) :
 
             _window = window;
 
-            _window.KeyDown += Window_KeyDown;
+            _window.KeyDown += OnWindowKeyDown;
-            _window.KeyUp += Window_KeyUp;
+            _window.KeyUp += OnWindowKeyUp;
             _window.GotKeyboardFocus += (sender, e) => _updateAnyKeyDown = true;
         }
 
@@ -61,7 +61,7 @@ private bool IsKeyDown(Key key)
             return _states[(int)key];
         }
 
-        private void Window_KeyDown(object sender, KeyEventArgs e)
+        private void OnWindowKeyDown(object sender, KeyEventArgs e)
         {
             _states[(int)((e.Key == Key.System) ? e.SystemKey : e.Key)] = true;
             IsAnyKeyDown = true;
@@ -69,12 +69,12 @@ private void Window_KeyDown(object sender, KeyEventArgs e)
             int asciiKey = GetAsciiKey(e.Key, e.KeyboardDevice);
             if (asciiKey >= 0)
             {
-                RaiseAsciiKeyDown(asciiKey);
+                OnAsciiKeyDown(asciiKey);
                 e.Handled = true;
             }
         }
 
-        private void Window_KeyUp(object sender, KeyEventArgs e)
+        private void OnWindowKeyUp(object sender, KeyEventArgs e)
         {
             _states[(int)((e.Key == Key.System) ? e.SystemKey : e.Key)] = false;
             _updateAnyKeyDown = true;

Virtu/Xna/Services/XnaAudioService.cs

@@ -18,7 +18,7 @@ public XnaAudioService(Machine machine, GameBase game) :
             _game = game;
 
             _directSound.Start(_game.Window.Handle);
-            _directSound.Update += DirectSound_Update;
+            _directSound.Update += OnDirectSoundUpdate;
             _game.Exiting += (sender, e) => _directSound.Stop();
         }
 
@@ -30,7 +30,7 @@ protected override void Dispose(bool disposing)
             }
         }
 
-        private void DirectSound_Update(object sender, DirectSoundUpdateEventArgs e)
+        private void OnDirectSoundUpdate(object sender, DirectSoundUpdateEventArgs e)
         {
             IntPtr buffer = e.Buffer;
             Update(e.BufferSize, (source, count) => 

Virtu/Xna/Services/XnaKeyboardService.cs

@@ -48,7 +48,7 @@ public override void Update()
 #endif
                             if (asciiKey >= 0)
                             {
-                                RaiseAsciiKeyDown(asciiKey);
+                                OnAsciiKeyDown(asciiKey);
                             }
                         }
                     }
@@ -73,7 +73,7 @@ public override void Update()
 #endif
                     if (asciiKey >= 0)
                     {
-                        RaiseAsciiKeyDown(asciiKey);
+                        OnAsciiKeyDown(asciiKey);
                     }
                 }
             }

Virtu/Xna/Services/XnaVideoService.cs

@@ -18,8 +18,8 @@ public XnaVideoService(Machine machine, GameBase game) :
 
             _game = game;
 
-            _game.GraphicsDeviceManager.PreparingDeviceSettings += GraphicsDeviceManager_PreparingDeviceSettings;
+            _game.GraphicsDeviceManager.PreparingDeviceSettings += OnGraphicsDeviceManagerPreparingDeviceSettings;
-            _game.GraphicsDeviceService.DeviceCreated += GraphicsDeviceService_DeviceCreated;
+            _game.GraphicsDeviceService.DeviceCreated += OnGraphicsDeviceServiceDeviceCreated;
             _game.GraphicsDeviceService.DeviceReset += (sender, e) => SetTexturePosition();
         }
 
@@ -68,7 +68,7 @@ protected override void Dispose(bool disposing)
             }
         }
 
-        private void GraphicsDeviceManager_PreparingDeviceSettings(object sender, PreparingDeviceSettingsEventArgs e)
+        private void OnGraphicsDeviceManagerPreparingDeviceSettings(object sender, PreparingDeviceSettingsEventArgs e)
         {
             DisplayMode displayMode = e.GraphicsDeviceInformation.Adapter.CurrentDisplayMode;
             PresentationParameters presentationParameters = e.GraphicsDeviceInformation.PresentationParameters;
@@ -83,7 +83,7 @@ private void GraphicsDeviceManager_PreparingDeviceSettings(object sender, Prepar
             }
         }
 
-        private void GraphicsDeviceService_DeviceCreated(object sender, EventArgs e)
+        private void OnGraphicsDeviceServiceDeviceCreated(object sender, EventArgs e)
         {
             _graphicsDevice = _game.GraphicsDevice;
             _spriteBatch = new SpriteBatch(_graphicsDevice);