LagFrame implementation

BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/SpectrumBase.Input.cs

@@ -204,6 +204,11 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         {
             return JoystickCollection.Where(a => a.JoyType == type).FirstOrDefault();
         }
+
+        /// <summary>
+        /// Signs whether input read has been requested
+        /// </summary>
+        protected bool InputRead { get; set; }
     }
 }
 

BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/SpectrumBase.cs

@@ -140,6 +140,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// </summary>
         public virtual void ExecuteFrame()
         {
+            InputRead = false;
+
             FrameCompleted = false;
             BuzzerDevice.StartFrame();
             if (AYDevice != null)
@@ -179,6 +181,9 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             TapeDevice.EndFrame();
 
             FrameCompleted = true;
+
+            // is this a lag frame?
+            Spectrum.IsLagFrame = !InputRead;
         }
         
         /// <summary>

BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128K/ZX128.Port.cs

@@ -15,6 +15,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// <returns></returns>
         public override byte ReadPort(ushort port)
         {
+            InputRead = true;
+
             int result = 0xFF;
 
             // Check whether the low bit is reset
@@ -29,6 +31,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             {
                 if (LocateUniqueJoystick(JoystickType.Kempston) != null)
                     return (byte)((KempstonJoystick)LocateUniqueJoystick(JoystickType.Kempston) as KempstonJoystick).JoyLine;
+
+                InputRead = true;
             }
             else if (lowBitReset)
             {
@@ -43,28 +47,45 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
                 */
 
                 if ((port & 0x8000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[7];
+                }
 
                 if ((port & 0x4000) == 0)
+                { 
                     result &= KeyboardDevice.KeyLine[6];
+                }
 
                 if ((port & 0x2000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[5];
+                }                    
 
                 if ((port & 0x1000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[4];
+                }
                     
                 if ((port & 0x800) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[3];
+                }                    
 
                 if ((port & 0x400) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[2];
+                }                    
 
                 if ((port & 0x200) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[1];
+                }                    
 
                 if ((port & 0x100) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[0];
+                }
+                    
 
                 result = result & 0x1f; //mask out lower 4 bits
                 result = result | 0xa0; //set bit 5 & 7 to 1

BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus3/ZX128Plus3.Port.cs

@@ -15,6 +15,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// <returns></returns>
         public override byte ReadPort(ushort port)
         {
+            InputRead = true;
+
             int result = 0xFF;
 
             // Check whether the low bit is reset
@@ -28,6 +30,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             {
                 if (LocateUniqueJoystick(JoystickType.Kempston) != null)
                     return (byte)((KempstonJoystick)LocateUniqueJoystick(JoystickType.Kempston) as KempstonJoystick).JoyLine;
+
+                InputRead = true;
             }
             else if (lowBitReset)
             {
@@ -42,28 +46,44 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
                 */
 
                 if ((port & 0x8000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[7];
+                }                    
 
                 if ((port & 0x4000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[6];
+                }                    
 
                 if ((port & 0x2000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[5];
+                }                    
 
                 if ((port & 0x1000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[4];
+                }                    
 
                 if ((port & 0x800) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[3];
+                }                    
 
                 if ((port & 0x400) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[2];
+                }                    
 
                 if ((port & 0x200) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[1];
+                }                    
 
                 if ((port & 0x100) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[0];
+                }                    
 
                 result = result & 0x1f; //mask out lower 4 bits
                 result = result | 0xa0; //set bit 5 & 7 to 1

BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum48K/ZX48.Port.cs

@@ -15,6 +15,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// <returns></returns>
         public override byte ReadPort(ushort port)
         {
+            InputRead = true;
+
             int result = 0xFF;
 
             // Check whether the low bit is reset
@@ -28,6 +30,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             {
                 if (LocateUniqueJoystick(JoystickType.Kempston) != null)
                     return (byte)((KempstonJoystick)LocateUniqueJoystick(JoystickType.Kempston) as KempstonJoystick).JoyLine;
+
+                InputRead = true;
             }
             else if (lowBitReset)
             {
@@ -44,28 +48,44 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
                 */
 
                 if ((port & 0x8000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[7];
+                }                    
 
                 if ((port & 0x4000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[6];
+                }                    
 
                 if ((port & 0x2000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[5];
+                }                    
 
                 if ((port & 0x1000) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[4];
+                }                    
 
                 if ((port & 0x800) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[3];
+                }                    
 
                 if ((port & 0x400) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[2];
+                }                    
 
                 if ((port & 0x200) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[1];
+                }                    
 
                 if ((port & 0x100) == 0)
+                {
                     result &= KeyboardDevice.KeyLine[0];
+                }                    
 
                 result = result & 0x1f; //mask out lower 4 bits
                 result = result | 0xa0; //set bit 5 & 7 to 1

BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IEmulator.cs

@@ -13,6 +13,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         {            
             _controller = controller;
 
+            _isLag = true;
+
             if (_tracer.Enabled)
             {
                 _cpu.TraceCallback = s => _tracer.Put(s);
@@ -23,6 +25,11 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             }
 
             _machine.ExecuteFrame();
+
+            if (_isLag)
+            {
+                _lagCount++;
+            }
         }
 
         public int Frame => _machine.FrameCount;

BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IInputPollable.cs

@@ -21,6 +21,6 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         public IInputCallbackSystem InputCallbacks { get; }
 
         private int _lagCount = 0;
-        private bool _isLag = true;
+        private bool _isLag = false;
     }
 }