diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.Input.cs b/BizHawk.Emulation/Computers/Commodore64/C64.Input.cs
index 40c31c5c6d..274fe1529f 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.Input.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.Input.cs
@@ -70,14 +70,8 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			byte portB = inputAdapter1.Data;
 			byte resultA = 0xFF;
 			byte resultB = 0xFF;
-
-			for (uint i = 0; i < 5; i++)
-			{
-				if (joystickPressed[1, i])
-					resultA &= inputBitMask[i];
-				if (joystickPressed[0, i])
-					resultB &= inputBitMask[i];
-			}
+			byte joyA = 0xFF;
+			byte joyB = 0xFF;
 
 			for (uint i = 0; i < 8; i++)
 			{
@@ -94,8 +88,18 @@ namespace BizHawk.Emulation.Computers.Commodore64
 				}
 			}
 
-			inputAdapter0.ForceWrite((byte)(resultA & portB));
+			for (uint i = 0; i < 5; i++)
+			{
+				if (joystickPressed[1, i])
+					joyA &= inputBitMask[i];
+				if (joystickPressed[0, i])
+					joyB &= inputBitMask[i];
+			}
+
+			inputAdapter0.Data = resultA;
 			inputAdapter1.Data = resultB;
+			inputAdapter0.MaskWrite(joyB);
+			inputAdapter1.MaskWrite(joyA);
 		}
 	}
 }
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs
index 5337040508..c37ca46753 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs
@@ -66,6 +66,9 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
 		public void ExecutePhase2()
 		{
+			if (chips.vic.BA)
+				freezeCpu = false;
+
 			if (chips.vic.AEC && !freezeCpu)
 			{
 				// the 6502 core expects active high
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6526.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6526.cs
index b848b07817..7062014ddd 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6526.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6526.cs
@@ -406,10 +406,10 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			switch (addr)
 			{
 				case 0x0:
-					val = portData[0];
+					val = (byte)(portData[0] & portMask[0]);
 					break;
 				case 0x1:
-					val = portData[1];
+					val = (byte)(portData[1] & portMask[1]);
 					break;
 				case 0x2:
 					val = portDir[0];
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Port.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Port.cs
index 7016108962..434806e4c9 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Port.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Port.cs
@@ -32,14 +32,14 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 	public class PortAdapter
 	{
 		private Action<byte> actWrite;
-		private Action<byte> actWriteForce;
+		private Action<byte> actWriteMask;
 		private Func<byte> funcRead;
 
-		public PortAdapter(Func<byte> newRead, Action<byte> newWrite, Action<byte> newWriteForce)
+		public PortAdapter(Func<byte> newRead, Action<byte> newWrite, Action<byte> newWriteMask)
 		{
 			funcRead = newRead;
 			actWrite = newWrite;
-			actWriteForce = newWriteForce;
+			actWriteMask = newWriteMask;
 		}
 
 		public byte Data
@@ -54,9 +54,9 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			}
 		}
 
-		public void ForceWrite(byte val)
+		public void MaskWrite(byte val)
 		{
-			actWriteForce(val);
+			actWriteMask(val);
 		}
 	}
 }
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Timer.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Timer.cs
index 96dbc22c6b..553a5e96f2 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Timer.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Timer.cs
@@ -12,6 +12,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		protected bool pinIRQ;
 		protected byte[] portData;
 		protected byte[] portDir;
+		protected byte[] portMask;
 		protected uint[] timer;
 		protected uint[] timerLatch;
 		protected bool[] timerOn;
@@ -21,6 +22,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		{
 			portData = new byte[2];
 			portDir = new byte[2];
+			portMask = new byte[2];
 			timer = new uint[2];
 			timerLatch = new uint[2];
 			timerOn = new bool[2];
@@ -31,7 +33,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		{
 			get
 			{
-				return Port.GetAdapter(ReadPort0, ExternalWritePort0, ExternalWriteForce0);
+				return Port.GetAdapter(ReadPort0, ExternalWritePort0, ExternalWriteMask0);
 			}
 		}
 
@@ -39,18 +41,18 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		{
 			get
 			{
-				return Port.GetAdapter(ReadPort1, ExternalWritePort1, ExternalWriteForce1);
+				return Port.GetAdapter(ReadPort1, ExternalWritePort1, ExternalWriteMask1);
 			}
 		}
 
-		private void ExternalWriteForce0(byte data)
+		private void ExternalWriteMask0(byte data)
 		{
-			portData[0] = data;
+			portMask[0] = data;
 		}
 
-		private void ExternalWriteForce1(byte data)
+		private void ExternalWriteMask1(byte data)
 		{
-			portData[1] = data;
+			portMask[1] = data;
 		}
 
 		private void ExternalWritePort(uint index, byte data)
@@ -77,6 +79,10 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			pinIRQ = true;
 			portDir[0] = 0xFF;
 			portDir[1] = 0xFF;
+			portMask[0] = 0xFF;
+			portMask[1] = 0xFF;
+			portData[0] = 0xFF;
+			portData[1] = 0xFF;
 		}
 
 		public bool IRQ