From 1c18da52b3207a438a82a8e9a322181e75358952 Mon Sep 17 00:00:00 2001
From: saxxonpike <saxxonpike@gmail.com>
Date: Sat, 24 Aug 2013 20:13:16 +0000
Subject: [PATCH] Commodore64: Border unit implemented fully, timing is much
 better now and works for both PAL and NTSC.

---
 .../Computers/Commodore64/C64.Core.cs         |  2 +-
 .../Computers/Commodore64/C64.Motherboard.cs  |  2 +-
 .../Commodore64/C64.MotherboardInterface.cs   |  2 +-
 .../Computers/Commodore64/C64.Savestate.cs    |  2 +-
 .../Computers/Commodore64/C64.cs              |  2 +-
 .../Computers/Commodore64/MOS/MOS6567.cs      | 24 ++++++--
 .../Computers/Commodore64/MOS/MOS6569.cs      | 24 ++++++--
 .../Computers/Commodore64/MOS/Sid.cs          | 10 +++-
 .../Computers/Commodore64/MOS/Vic.Parse.cs    |  6 +-
 .../Computers/Commodore64/MOS/Vic.Render.cs   | 58 ++++++++++---------
 .../Computers/Commodore64/MOS/Vic.State.cs    | 10 ++++
 .../Commodore64/MOS/Vic.TimingBuilder.cs      | 36 +++++++++++-
 .../Commodore64/MOS/Vic.VideoProvider.cs      |  8 +--
 .../Computers/Commodore64/MOS/Vic.cs          | 27 ++++-----
 .../Computers/Commodore64/Sync.cs             |  1 -
 15 files changed, 149 insertions(+), 65 deletions(-)

diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.Core.cs b/BizHawk.Emulation/Computers/Commodore64/C64.Core.cs
index 4cb533811b..aaf040add4 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.Core.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.Core.cs
@@ -11,7 +11,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 		PAL
 	}
 
-	public partial class C64 : IEmulator
+	sealed public partial class C64 : IEmulator
 	{
 		private Motherboard board;
 		private bool loadPrg;
diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.Motherboard.cs b/BizHawk.Emulation/Computers/Commodore64/C64.Motherboard.cs
index c2f3534a70..eaaf3c5c01 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.Motherboard.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.Motherboard.cs
@@ -6,7 +6,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
     /// <summary>
     /// Contains the onboard chipset and glue.
     /// </summary>
-	public partial class Motherboard
+	sealed public partial class Motherboard
 	{
 		// chips
 		public Chip23XX basicRom;
diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.MotherboardInterface.cs b/BizHawk.Emulation/Computers/Commodore64/C64.MotherboardInterface.cs
index 0c395f4e17..f8650b0fdc 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.MotherboardInterface.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.MotherboardInterface.cs
@@ -7,7 +7,7 @@ using System.Text;
 
 namespace BizHawk.Emulation.Computers.Commodore64
 {
-    public partial class Motherboard
+    sealed public partial class Motherboard
     {
         bool CassPort_ReadDataOutput()
         {
diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.Savestate.cs b/BizHawk.Emulation/Computers/Commodore64/C64.Savestate.cs
index e33f4466b1..cce2af2d93 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.Savestate.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.Savestate.cs
@@ -2,7 +2,7 @@
 
 namespace BizHawk.Emulation.Computers.Commodore64
 {
-	public partial class C64 : IEmulator
+	sealed public partial class C64 : IEmulator
 	{
 		public void ClearSaveRam()
 		{
diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.cs b/BizHawk.Emulation/Computers/Commodore64/C64.cs
index 76e8dd50f5..21337542e9 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.cs
@@ -5,7 +5,7 @@ using System.IO;
 
 namespace BizHawk.Emulation.Computers.Commodore64
 {
-	public partial class  C64 : IEmulator
+	sealed public partial class C64 : IEmulator
 	{
 		// internal variables
 		private bool _islag = true;
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6567.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6567.cs
index 036a7ef21b..6a827eeb5c 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6567.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6567.cs
@@ -1,12 +1,22 @@
-namespace BizHawk.Emulation.Computers.Commodore64.MOS
+using System.Drawing;
+
+namespace BizHawk.Emulation.Computers.Commodore64.MOS
 {
 	// vic ntsc
 	static public class MOS6567
 	{
-        static int[] timing = Vic.TimingBuilder_XRaster(0x19C, 0x200, 0x208, 0x18C, 8);
+        static int cycles = 65;
+        static int lines = 263;
+        static int vblankstart = 0x00D;
+        static int vblankend = 0x018;
+        static int hblankstart = 0x18C;
+        static int hblankend = 0x1F0;
+        static int scanwidth = cycles * 8;
+
+        static int[] timing = Vic.TimingBuilder_XRaster(0x19C, 0x200, scanwidth, 0x18C, 8);
         static int[] fetch = Vic.TimingBuilder_Fetch(timing, 0x174);
         static int[] ba = Vic.TimingBuilder_BA(fetch);
-        static int[] act = Vic.TimingBuilder_Act(timing, 0x004, 0x14C);
+        static int[] act = Vic.TimingBuilder_Act(timing, 0x004, 0x14C, hblankstart, hblankend);
 
         static int[][] pipeline = new int[][]
 			{
@@ -18,7 +28,13 @@
 
         static public Vic Create()
         {
-            return new Vic(65, 263, pipeline, 14318181 / 14);
+            return new Vic(
+                cycles, lines, 
+                pipeline, 
+                14318181 / 14,
+                hblankstart, hblankend,
+                vblankstart, vblankend
+                );
         }
 	}
 }
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6569.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6569.cs
index 5780272afa..3ed96d82b3 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6569.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6569.cs
@@ -1,12 +1,22 @@
-namespace BizHawk.Emulation.Computers.Commodore64.MOS
+using System.Drawing;
+
+namespace BizHawk.Emulation.Computers.Commodore64.MOS
 {
 	// vic pal
 	static public class MOS6569
 	{
-        static int[] timing = Vic.TimingBuilder_XRaster(0x194, 0x1F8, 0x1F8, -1, -1);
+        static int cycles = 63;
+        static int lines = 312;
+        static int vblankstart = 0x12C;
+        static int vblankend = 0x00F;
+        static int hblankstart = 0x17C;
+        static int hblankend = 0x1E0;
+        static int scanwidth = cycles * 8;
+
+        static int[] timing = Vic.TimingBuilder_XRaster(0x194, 0x1F8, scanwidth, -1, -1);
         static int[] fetch = Vic.TimingBuilder_Fetch(timing, 0x164);
         static int[] ba = Vic.TimingBuilder_BA(fetch);
-        static int[] act = Vic.TimingBuilder_Act(timing, 0x004, 0x14C);
+        static int[] act = Vic.TimingBuilder_Act(timing, 0x004, 0x14C, hblankstart, hblankend);
 
         static int[][] pipeline = new int[][]
 			{
@@ -18,7 +28,13 @@
 
         static public Vic Create()
         {
-            return new Vic(63, 312, pipeline, 17734472 / 18);
+            return new Vic(
+                cycles, lines, 
+                pipeline, 
+                17734472 / 18,
+                hblankstart, hblankend,
+                vblankstart, vblankend
+                );
         }
 	}
 }
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Sid.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Sid.cs
index 64f0ea1ae8..88dda110bf 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Sid.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Sid.cs
@@ -613,11 +613,15 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		public Sid(int[][] newWaveformTable, int newSampleRate, Region newRegion)
 		{
 			uint cyclesPerSec = 0;
+            uint cyclesNum;
+            uint cyclesDen;
+            uint sampleRate = 44100;
 
 			switch (newRegion)
 			{
-				case Region.NTSC: cyclesPerSec = 14318181 / 14; break;
-				case Region.PAL: cyclesPerSec = 17734472 / 18; break;
+                case Region.NTSC: cyclesNum = 14318181; cyclesDen = 14; break;
+				case Region.PAL: cyclesNum = 17734472; cyclesDen = 18; break;
+                default: return;
 			}
 
 			waveformTable = newWaveformTable;
@@ -636,7 +640,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			for (int i = 0; i < 3; i++)
 				filterEnable[i] = false;
 
-			resampler = new Sound.Utilities.SpeexResampler(0, cyclesPerSec, 44100, cyclesPerSec, 44100, null, null);
+            resampler = new Sound.Utilities.SpeexResampler(0, cyclesNum, sampleRate * cyclesDen, cyclesNum, sampleRate * cyclesDen, null, null);
 		}
 
 		public void Dispose()
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.Parse.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.Parse.cs
index 6758e386c3..6002ce5714 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.Parse.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.Parse.cs
@@ -19,6 +19,8 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
         public const int pipelineChkBrdR1 = 256;
         public const int pipelineChkSprDisp = 512;
         public const int pipelineUpdateRc = 1024;
+        public const int pipelineHBlankL = 0x10000000;
+        public const int pipelineHBlankR = 0x20000000;
         public const int pipelineHoldX = 0x40000000;
         public const int rasterIrqLine0Cycle = 1;
         public const int rasterIrqLineXCycle = 0;
@@ -43,6 +45,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
                 // apply X location
                 rasterX = pipeline[0][cycleIndex];
+                rasterXHold = ((parseact & pipelineHoldX) != 0);
 
                 // perform fetch
                 parsefetchType = parsefetch & 0xFF00;
@@ -158,7 +161,8 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
                 // perform actions
                 borderCheckLEnable = ((parseact & (pipelineChkBrdL0 | pipelineChkBrdL1)) != 0);
                 borderCheckREnable = ((parseact & (pipelineChkBrdR0 | pipelineChkBrdR1)) != 0);
-                rasterXHold = ((parseact & pipelineHoldX) != 0);
+                hblankCheckEnableL = ((parseact & pipelineHBlankL) != 0);
+                hblankCheckEnableR = ((parseact & pipelineHBlankR) != 0);
 
                 if (parseact != 0)
                 {
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.Render.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.Render.cs
index e06a671993..db5a9e1899 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.Render.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.Render.cs
@@ -7,6 +7,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 {
     sealed public partial class Vic
     {
+        int borderSR;
         int ecmPixel;
         int pixel;
         int[] pixelBackgroundBuffer;
@@ -33,47 +34,52 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
         private void Render()
         {
-            renderEnabled = bufRect.Contains(bufPoint);
+            if (hblankCheckEnableL)
+            {
+                if (rasterX == hblankEnd)
+                    hblank = false;
+            }
+            else if (hblankCheckEnableR)
+            {
+                if (rasterX == hblankStart)
+                    hblank = true;
+            }
+            renderEnabled = !hblank && !vblank; //bufRect.Contains(bufPoint);
 
             for (int i = 0; i < 4; i++)
             {
-                if (borderCheckLEnable)
+                if (borderCheckLEnable && (rasterX == borderL))
                 {
-                    if (rasterX == borderL)
-                    {
-                        if (rasterLine == borderB)
-                            borderOnVertical = true;
-                        if (rasterLine == borderT && displayEnable)
-                            borderOnVertical = false;
-                        if (!borderOnVertical)
-                            borderOnMain = false;
-                    }
-                }
-                if (borderCheckREnable)
-                {
-                    if (rasterX == borderR)
-                        borderOnMain = true;
+                    if (rasterLine == borderB)
+                        borderOnVertical = true;
+                    if (rasterLine == borderT && displayEnable)
+                        borderOnVertical = false;
+                    if (!borderOnVertical)
+                        borderOnMain = false;
                 }
 
+                if (borderCheckREnable && (rasterX == borderR))
+                    borderOnMain = true;
+
                 // recall pixel from buffer
                 pixel = pixelBuffer[pixelBufferIndex];
 
+                // border doesn't work with the background buffer
+                borderSR <<= 1;
+                if (borderOnMain || borderOnVertical)
+                    borderSR |= 1;
+                if ((borderSR & 0x100) != 0)
+                    pixel = borderColor;
+
                 // plot pixel if within viewing area
                 if (renderEnabled)
                 {
+
                     buf[bufOffset] = palette[pixel];
                     bufOffset++;
                     if (bufOffset == bufLength)
                         bufOffset = 0;
                 }
-                bufPoint.X++;
-                if (bufPoint.X == bufWidth)
-                {
-                    bufPoint.X = 0;
-                    bufPoint.Y++;
-                    if (bufPoint.Y == bufHeight)
-                        bufPoint.Y = 0;
-                }
 
                 // put the pixel from the background buffer into the main buffer
                 pixel = pixelBackgroundBuffer[pixelBackgroundBufferIndex];
@@ -143,10 +149,6 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
                     }
                 }
 
-                // border doesn't work with the background buffer
-                if (borderOnMain || borderOnVertical)
-                    pixel = borderColor;
-
                 // store pixel in buffer
                 pixelBuffer[pixelBufferIndex] = pixel;
 
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.State.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.State.cs
index 88536da368..9eb7a1d135 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.State.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.State.cs
@@ -42,11 +42,16 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
         bool enableIntSpriteCollision;
         bool enableIntSpriteDataCollision;
         bool extraColorMode;
+        bool hblank;
         bool idle;
         bool intLightPen;
         bool intRaster;
         bool intSpriteCollision;
         bool intSpriteDataCollision;
+        int hblankEnd;
+        int hblankStart;
+        bool hblankCheckEnableL;
+        bool hblankCheckEnableR;
         int lastRasterLine;
         int lightPenX;
         int lightPenY;
@@ -69,6 +74,9 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
         int spriteMulticolor1;
         Sprite[] sprites;
         int sr;
+        bool vblank;
+        int vblankEnd;
+        int vblankStart;
         int vc;
         int vcbase;
         int vmli;
@@ -105,6 +113,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
             enableIntSpriteCollision = false;
             enableIntSpriteDataCollision = false;
             extraColorMode = false;
+            hblank = true;
             idle = true;
             intLightPen = false;
             intRaster = false;
@@ -127,6 +136,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
             spriteMulticolor0 = 0;
             spriteMulticolor1 = 0;
             sr = 0;
+            vblank = true;
             vc = 0;
             vcbase = 0;
             vmli = 0;
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.TimingBuilder.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.TimingBuilder.cs
index 687679b7f6..a7030f07b9 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.TimingBuilder.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.TimingBuilder.cs
@@ -22,7 +22,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			pipelineChkSprDisp, pipelineUpdateRc
         };
 
-        static public int[] TimingBuilder_Act(int[] timing, int cycle14, int cycle55)
+        static public int[] TimingBuilder_Act(int[] timing, int cycle14, int cycle55, int hblankStart, int hblankEnd)
         {
             List<int> result = new List<int>();
 
@@ -39,6 +39,8 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
                     result.Add(0);
             }
 
+            bool hBlankL = false;
+            bool hBlankR = false;
             for (int i = 0; i < length; i++)
             {
                 // pipeline raster X delay
@@ -54,6 +56,10 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
                     result[i] |= pipelineChkBrdR0;
                 if (timing[i] == 0x15C)
                     result[i] |= pipelineChkBrdR1;
+                if (timing[i] == (hblankStart & 0xFFD))
+                    result[i] |= pipelineHBlankR;
+                if (timing[i] == (hblankEnd & 0xFFD))
+                    result[i] |= pipelineHBlankL;
             }
 
             return result.ToArray();
@@ -196,6 +202,34 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
             return result.ToArray();
         }
 
+        static public int TimingBuilder_ScreenHeight(int vblankStart, int vblankEnd, int lines)
+        {
+            int offset = vblankEnd;
+            int result = 0;
+            while (true)
+            {
+                if (offset >= lines)
+                    offset -= lines;
+                if (offset == vblankStart)
+                    return result;
+                offset++;
+                result++;
+            }
+        }
+
+        static public int TimingBuilder_ScreenWidth(int[] timing, int hblankStart, int hblankEnd)
+        {
+            int length = timing.Length;
+            int result = 0;
+            int offset = 0;
+
+            while (timing[offset] != hblankEnd) { offset = (offset + 1) % length; }
+            while (timing[offset] != hblankStart) { offset = (offset + 1) % length; result++; }
+            //while (timing[offset] == hblankStart) { offset = (offset + 1) % length; result++; }
+
+            return (result * 4);
+        }
+
         static public int[] TimingBuilder_XRaster(int start, int width, int count, int delayOffset, int delayAmount)
         {
             List<int> result = new List<int>();
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.VideoProvider.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.VideoProvider.cs
index 0cb281254a..74b1b34dfa 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.VideoProvider.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.VideoProvider.cs
@@ -8,8 +8,6 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		int bufHeight;
 		int bufLength;
 		int bufOffset;
-		Point bufPoint;
-		Rectangle bufRect;
 		int bufWidth;
 
 		// palette
@@ -40,12 +38,12 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
 		public int BufferHeight
 		{
-			get { return bufRect.Height; }
+			get { return bufHeight; }
 		}
 
 		public int BufferWidth
 		{
-			get { return bufRect.Width; }
+			get { return bufWidth; }
 		}
 
 		public int[] GetVideoBuffer()
@@ -55,7 +53,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
 		public int VirtualWidth
 		{
-			get { return bufRect.Width; }
+            get { return bufWidth; }
 		}
 	}
 }
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.cs
index 1aa22d420d..e6473cd411 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Vic.cs
@@ -18,12 +18,16 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		int totalCycles;
 		int totalLines;
 
-		public Vic(int newCycles, int newLines, int[][] newPipeline, int newCyclesPerSec)
+		public Vic(int newCycles, int newLines, int[][] newPipeline, int newCyclesPerSec, int hblankStart, int hblankEnd, int vblankStart, int vblankEnd)
 		{
-			
 			{
                 debugScreen = false;
 
+                this.hblankStart = hblankStart;
+                this.hblankEnd = hblankEnd;
+                this.vblankStart = vblankStart;
+                this.vblankEnd = vblankEnd;
+
                 totalCycles = newCycles;
 				totalLines = newLines;
 				pipeline = newPipeline;
@@ -31,19 +35,11 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 				pixelBufferDelay = 12;
 				pixelBackgroundBufferDelay = 4;
 
-                if (debugScreen)
-                {
-                    bufRect = new Rectangle(0, 0, totalCycles * 8, totalLines);
-                }
-                else
-                {
-                    bufRect = new Rectangle(136 - 24, 51 - 24, 320 + 48, 200 + 48);
-                }
+                bufWidth = TimingBuilder_ScreenWidth(pipeline[0], hblankStart, hblankEnd);
+                bufHeight = TimingBuilder_ScreenHeight(vblankStart, vblankEnd, newLines);
 
-				buf = new int[bufRect.Width * bufRect.Height];
+                buf = new int[bufWidth * bufHeight];
 				bufLength = buf.Length;
-				bufWidth = (totalCycles * 8);
-				bufHeight = (totalLines);
 
 				sprites = new Sprite[8];
 				for (int i = 0; i < 8; i++)
@@ -145,6 +141,11 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
                     if (rasterLine == borderT && displayEnable)
                         borderOnVertical = false;
 
+                    if (rasterLine == vblankStart)
+                        vblank = true;
+                    if (rasterLine == vblankEnd)
+                        vblank = false;
+
                     cycleIndex = 0;
                     cycle = 0;
                     rasterLine++;
diff --git a/BizHawk.Emulation/Computers/Commodore64/Sync.cs b/BizHawk.Emulation/Computers/Commodore64/Sync.cs
index 24cb3b2102..3b80a38de8 100644
--- a/BizHawk.Emulation/Computers/Commodore64/Sync.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/Sync.cs
@@ -24,7 +24,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
             IntBuffer refIntBuffer;
             Int32 refPointX;
             Int32 refPointY;
-            Rectangle refRect;
             SByte refSByte;
             UInt16 refUInt16;
             UInt32 refUInt32;