diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.Core.cs b/BizHawk.Emulation/Computers/Commodore64/C64.Core.cs
index 11cdd346e3..01aadbe677 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.Core.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.Core.cs
@@ -55,6 +55,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			byte[] diskRom = File.ReadAllBytes(diskPath);
 
 			disk = new VIC1541(initRegion, diskRom);
+			disk.Connect(board.serPort);
 		}
 
 		private void InitMedia()
@@ -84,7 +85,6 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			string basicFile = "basic";
 			string charFile = "chargen";
 			string kernalFile = "kernal";
-			string diskFile = "dos1541";
 
 			string basicPath = Path.Combine(sourceFolder, basicFile);
 			string charPath = Path.Combine(sourceFolder, charFile);
@@ -109,7 +109,7 @@ namespace BizHawk.Emulation.Computers.Commodore64
 		{
 			get
 			{
-				return false;
+				return (disk.PeekVia1(0x00) & 0x08) != 0;
 			}
 		}
 
diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.Motherboard.cs b/BizHawk.Emulation/Computers/Commodore64/C64.Motherboard.cs
index 794f8e40c6..2f274a25a5 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.Motherboard.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.Motherboard.cs
@@ -151,8 +151,16 @@ namespace BizHawk.Emulation.Computers.Commodore64
 			cia1.ReadPortB = (() => { return cia1DataB; });
 			cia1.WriteDirA = ((byte val) => { cia1DirA = val; });
 			cia1.WriteDirB = ((byte val) => { cia1DirB = val; });
-			cia1.WritePortA = ((byte val) => { cia1DataA = Port.CPUWrite(cia1DataA, val, cia1DirA); UpdateVicBank(); });
-			cia1.WritePortB = ((byte val) => { cia1DataB = Port.CPUWrite(cia1DataB, val, cia1DirB); });
+			cia1.WritePortA = ((byte val) => { 
+				cia1DataA = Port.CPUWrite(cia1DataA, val, cia1DirA); 
+				UpdateVicBank();
+				serPort.SystemWriteAtn((cia1DataA & 0x08) == 0);
+				serPort.SystemWriteClock((cia1DataA & 0x10) == 0);
+				serPort.SystemWriteData((cia1DataA & 0x20) == 0);
+			});
+			cia1.WritePortB = ((byte val) => {
+				cia1DataB = Port.CPUWrite(cia1DataB, val, cia1DirB);
+			});
 
 			cpu.PeekMemory = pla.Peek;
 			cpu.PokeMemory = pla.Poke;
diff --git a/BizHawk.Emulation/Computers/Commodore64/Disk/VIC1541.cs b/BizHawk.Emulation/Computers/Commodore64/Disk/VIC1541.cs
index a02e6bffc8..f8e088ef52 100644
--- a/BizHawk.Emulation/Computers/Commodore64/Disk/VIC1541.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/Disk/VIC1541.cs
@@ -79,14 +79,22 @@ namespace BizHawk.Emulation.Computers.Commodore64.Disk
 		public MOS6522 via0;
 		public MOS6522 via1;
 
-		public byte via0dirA;
-		public byte via0dirB;
-		public byte via0portA;
-		public byte via0portB;
-		public byte via1dirA;
-		public byte via1dirB;
-		public byte via1portA;
-		public byte via1portB;
+		public bool via0CA0;
+		public bool via0CA1;
+		public bool via0CB0;
+		public bool via0CB1;
+		public byte via0DataA;
+		public byte via0DataB;
+		public byte via0DirA;
+		public byte via0DirB;
+		public bool via1CA0;
+		public bool via1CA1;
+		public bool via1CB0;
+		public bool via1CB1;
+		public byte via1DataA;
+		public byte via1DataB;
+		public byte via1DirA;
+		public byte via1DirB;
 
 		public VIC1541Motherboard(Region initRegion, byte[] initRom)
 		{
@@ -119,28 +127,97 @@ namespace BizHawk.Emulation.Computers.Commodore64.Disk
 			pla.WriteVia0 = via0.Write;
 			pla.WriteVia1 = via1.Write;
 
-			via0dirA = 0x00;
-			via0dirB = 0x00;
-			via0portA = 0xFF;
-			via0portB = 0xFF;
-			via1dirA = 0x00;
-			via1dirB = 0x00;
-			via1portA = 0xFF;
-			via1portB = 0xFF;
+			via0CA0 = false;
+			via0CA1 = false;
+			via0CB0 = false;
+			via0CB1 = false;
+			via0DirA = 0x00;
+			via0DirB = 0x00;
+			via0DataA = 0xFF;
+			via0DataB = 0xFF;
+			via1CA0 = false;
+			via1CA1 = false;
+			via1CB0 = false;
+			via1CB1 = false;
+			via1DirA = 0x00;
+			via1DirB = 0x00;
+			via1DataA = 0xFF;
+			via1DataB = 0xFF;
+
+			via0.ReadCA0 = (() => { return via0CA0; });
+			via0.ReadCA1 = (() => { return via0CA1; });
+			via0.ReadCB0 = (() => { return via0CB0; });
+			via0.ReadCB1 = (() => { return via0CB1; });
+			via0.ReadDirA = (() => { return via0DirA; });
+			via0.ReadDirB = (() => { return via0DirB; });
+			via0.ReadPortA = (() => { return via0DataA; });
+			via0.ReadPortB = (() => { return via0DataB; });
+			via0.WriteCA0 = ((bool val) => { via0CA0 = val; });
+			via0.WriteCA1 = ((bool val) => { via0CA1 = val; });
+			via0.WriteCB0 = ((bool val) => { via0CB0 = val; });
+			via0.WriteCB1 = ((bool val) => { via0CB1 = val; });
+			via0.WriteDirA = ((byte val) => { via0DirA = val; });
+			via0.WriteDirB = ((byte val) => { via0DirB = val; });
+			via0.WritePortA = ((byte val) => {
+				via0DataA = Port.CPUWrite(via0DataA, val, via0DirA);
+			});
+			via0.WritePortB = ((byte val) => {
+				via0DataB = Port.CPUWrite(via0DataB, val, via0DirB);
+				serPort.DeviceWriteAtn((via0DataB & 0x80) != 0);
+				serPort.DeviceWriteClock((via0DataB & 0x08) != 0);
+				serPort.DeviceWriteData((via0DataB & 0x02) != 0);
+			});
+
+			via1.ReadCA0 = (() => { return via1CA0; });
+			via1.ReadCA1 = (() => { return via1CA1; });
+			via1.ReadCB0 = (() => { return via1CB0; });
+			via1.ReadCB1 = (() => { return via1CB1; });
+			via1.ReadDirA = (() => { return via1DirA; });
+			via1.ReadDirB = (() => { return via1DirB; });
+			via1.ReadPortA = (() => { return via1DataA; });
+			via1.ReadPortB = (() => { return via1DataB; });
+			via1.WriteCA0 = ((bool val) => { via1CA0 = val; });
+			via1.WriteCA1 = ((bool val) => { via1CA1 = val; });
+			via1.WriteCB0 = ((bool val) => { via1CB0 = val; });
+			via1.WriteCB1 = ((bool val) => { via1CB1 = val; });
+			via1.WriteDirA = ((byte val) => { via1DirA = val; });
+			via1.WriteDirB = ((byte val) => { via1DirB = val; });
+			via1.WritePortA = ((byte val) => { via1DataA = Port.CPUWrite(via1DataA, val, via1DirA); });
+			via1.WritePortB = ((byte val) => { via1DataB = Port.CPUWrite(via1DataB, val, via1DirB); });	
 		}
 
 		public void Connect(SerialPort newSerPort)
 		{
 			// TODO: verify polarity
 			serPort = newSerPort;
-			serPort.SystemReadAtn = (() => { return true; });
-			serPort.SystemReadClock = (() => { return ((via0portB & 0x8) != 0); }); // bit 3
-			serPort.SystemReadData = (() => { return ((via0portB & 0x2) != 0); }); // bit 1
-			serPort.SystemReadSrq = (() => { return true; });
-			serPort.SystemWriteAtn = ((bool val) => { via0portB = Port.ExternalWrite(via0portB, (byte)((via0portB & 0x7F) | (val ? 0x80 : 0x00)), via0dirB); });
-			serPort.SystemWriteClock = ((bool val) => { via0portB = Port.ExternalWrite(via0portB, (byte)((via0portB & 0xFB) | (val ? 0x04 : 0x00)), via0dirB); });
-			serPort.SystemWriteData = ((bool val) => { via0portB = Port.ExternalWrite(via0portB, (byte)((via0portB & 0xFE) | (val ? 0x01 : 0x00)), via0dirB); });
+			serPort.SystemReadAtn = (() => { 
+				return true;
+			});
+			serPort.SystemReadClock = (() => { 
+				return ((via0DataB & 0x08) != 0); 
+			}); // bit 3
+			serPort.SystemReadData = (() => { 
+				return ((via0DataB & 0x02) != 0); 
+			}); // bit 1
+			serPort.SystemReadSrq = (() => { 
+				return false; 
+			}); // device sensing
+			serPort.SystemWriteAtn = ((bool val) => {
+				via0DataB = Port.ExternalWrite(via0DataB, (byte)((via0DataB & 0x7F) | (val ? 0x80 : 0x00)), via0DataB);
+				via0CA0 = val;
+				// repeat to DATA OUT if bit 4 enabled on port B
+				if ((via0DataB & 0x10) != 0)
+					serPort.DeviceWriteData(val);
+			});
+			serPort.SystemWriteClock = ((bool val) => {
+				via0DataB = Port.ExternalWrite(via0DataB, (byte)((via0DataB & 0xFB) | (val ? 0x04 : 0x00)), via0DataB);
+			});
+			serPort.SystemWriteData = ((bool val) => {
+				via0DataB = Port.ExternalWrite(via0DataB, (byte)((via0DataB & 0xFE) | (val ? 0x01 : 0x00)), via0DataB);
+			});
 			serPort.SystemWriteReset = ((bool val) => { });
+
+			serPort.DeviceWriteSrq(false);
 		}
 
 		public void Execute()
@@ -148,6 +225,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.Disk
 			via0.ExecutePhase1();
 			via1.ExecutePhase1();
 
+			cpu.IRQ = !(via0.IRQ && via1.IRQ);
 			cpu.ExecuteOne();
 			via0.ExecutePhase2();
 			via1.ExecutePhase2();
@@ -158,6 +236,8 @@ namespace BizHawk.Emulation.Computers.Commodore64.Disk
 			for (uint i = 0; i < 0x7FF; i++)
 				ram[i] = 0x00;
 			cpu.PC = (ushort)(cpu.ReadMemory(0xFFFC) | ((ushort)cpu.ReadMemory(0xFFFD) << 8));
+			via0.HardReset();
+			via1.HardReset();
 		}
 	}
 }
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs
index ce391f6d3b..d8f42ab0d7 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs
@@ -26,7 +26,18 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		private const uint pcrControlLow = 6;
 		private const uint pcrControlHigh = 7;
 
+		private const uint tControlLoad = 0;
+		private const uint tControlContinuous = 1;
+		private const uint tControlLoadPB = 2;
+		private const uint tControlContinuousPB = 3;
+		private const uint tControlPulseCounter = 4;
+
+		private static byte[] portBit = new byte[] { 0x80, 0x40 };
+		private static byte[] portMask = new byte[] { 0x7F, 0xBF };
+
 		private uint acrShiftMode;
+		private bool caPulse;
+		private bool cbPulse;
 		private bool[] enableIrqCA;
 		private bool[] enableIrqCB;
 		private bool enableIrqSR;
@@ -35,18 +46,32 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		private bool[] irqCB;
 		private bool irqSR;
 		private bool[] irqT;
+		private bool[] lastca;
+		private bool[] lastcb;
+		private byte lastpb;
 		private byte paLatch;
 		private byte pbLatch;
 		private bool paLatchEnable;
 		private bool pbLatchEnable;
 		private byte paOut;
 		private byte pbOut;
+		private bool[] pbPulse;
 		private uint[] pcrControlA;
 		private uint[] pcrControlB;
 		private byte sr;
 		private uint srControl;
+		private uint srCounter;
 		private uint[] tControl;
 
+		public Func<bool> ReadCA0;
+		public Func<bool> ReadCA1;
+		public Func<bool> ReadCB0;
+		public Func<bool> ReadCB1;
+		public Action<bool> WriteCA0;
+		public Action<bool> WriteCA1;
+		public Action<bool> WriteCB0;
+		public Action<bool> WriteCB1;
+
 		public MOS6522()
 		{
 			enableIrqCA = new bool[2];
@@ -55,6 +80,9 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			irqCA = new bool[2];
 			irqCB = new bool[2];
 			irqT = new bool[2];
+			lastca = new bool[2];
+			lastcb = new bool[2];
+			pbPulse = new bool[2];
 			pcrControlA = new uint[2];
 			pcrControlB = new uint[2];
 			tControl = new uint[2];
@@ -63,6 +91,8 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		public void HardReset()
 		{
 			acrShiftMode = 0;
+			caPulse = false;
+			cbPulse = false;
 			enableIrqCA[0] = false;
 			enableIrqCA[1] = false;
 			enableIrqCB[0] = false;
@@ -77,12 +107,19 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			irqSR = false;
 			irqT[0] = false;
 			irqT[1] = false;
+			lastca[0] = ReadCA0();
+			lastca[1] = ReadCA1();
+			lastcb[0] = ReadCB0();
+			lastcb[1] = ReadCB1();
+			pbPulse[0] = false;
+			pbPulse[1] = false;
 			pcrControlA[0] = 0;
 			pcrControlA[1] = 0;
 			pcrControlB[0] = 0;
 			pcrControlB[1] = 0;
 			tControl[0] = 0;
 			tControl[1] = 0;
+			HardResetInternal();
 		}
 
 		// ------------------------------------
@@ -93,10 +130,185 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
 		public void ExecutePhase2()
 		{
-			pinIRQ = !(irqCA[0] | irqCA[1] |
-				irqCB[0] | irqCB[1] |
-				irqSR | irqT[0] | irqT[1]
+			bool ca0 = ReadCA0();
+			bool ca1 = ReadCA1();
+			bool cb0 = ReadCB0();
+			bool cb1 = ReadCB1();
+			bool ca0Trans = (lastca[0] != ca0);
+			bool ca1Trans = (lastca[1] != ca1);
+			bool cb0Trans = (lastcb[0] != cb0);
+			bool cb1Trans = (lastcb[1] != cb1);
+
+			// edge triggered interrupts
+
+			switch (pcrControlA[0])
+			{
+				case pcrControlInNegative:
+					if (lastca[0] && !ca0)
+						irqCA[0] = true;
+					break;
+				case pcrControlInPositive:
+					if (!lastca[0] && ca0)
+						irqCA[0] = true;
+					break;
+			}
+
+			switch (pcrControlB[0])
+			{
+				case pcrControlInNegative:
+					if (lastcb[0] && !cb0)
+						irqCB[0] = true;
+					break;
+				case pcrControlInPositive:
+					if (!lastcb[0] && cb0)
+						irqCB[0] = true;
+					break;
+			}
+
+			switch (pcrControlA[1])
+			{
+				case pcrControlInNegative:
+				case pcrControlInNegativeIndep:
+					if (lastca[1] && !ca1)
+						irqCA[1] = true;
+					break;
+				case pcrControlInPositive:
+				case pcrControlInPositiveIndep:
+					if (!lastca[1] && ca1)
+						irqCA[1] = true;
+					break;
+				case pcrControlHandshake:
+					if (lastca[0] != ca0)
+						WriteCA1(true);
+					break;
+				case pcrControlPulse:
+					if (caPulse)
+						caPulse = false;
+					else
+						WriteCA1(true);
+					break;
+				case pcrControlLow:
+					WriteCA1(false);
+					break;
+				case pcrControlHigh:
+					WriteCA1(true);
+					break;
+			}
+
+			switch (pcrControlB[1])
+			{
+				case pcrControlInNegative:
+				case pcrControlInNegativeIndep:
+					if (lastcb[1] && !cb1)
+						irqCB[1] = true;
+					break;
+				case pcrControlInPositive:
+				case pcrControlInPositiveIndep:
+					if (!lastcb[1] && cb1)
+						irqCB[1] = true;
+					break;
+				case pcrControlHandshake:
+					if (lastcb[0] != cb0)
+						WriteCB1(true);
+					break;
+				case pcrControlPulse:
+					if (cbPulse)
+						cbPulse = false;
+					else
+						WriteCB1(true);
+					break;
+				case pcrControlLow:
+					WriteCB1(false);
+					break;
+				case pcrControlHigh:
+					WriteCB1(true);
+					break;
+			}
+
+			// run timers
+			for (uint i = 0; i < 2; i++)
+			{
+				switch (tControl[i])
+				{
+					case tControlLoad:
+						if (timer[i] > 0)
+						{
+							timer[i]--;
+							if (timer[i] == 0)
+								irqT[i] = true;
+						}
+						break;
+					case tControlContinuous:
+						if (timer[i] > 0)
+						{
+							timer[i]--;
+							if (timer[i] == 0)
+							{
+								irqT[i] = true;
+								timer[i] = timerLatch[i];
+							}
+						}
+						break;
+					case tControlLoadPB:
+						if (pbPulse[i])
+							pbPulse[i] = false;
+						else
+							WritePortB((byte)(ReadPortB() & portMask[i]));
+
+						if (timer[i] > 0)
+						{
+							timer[i]--;
+							if (timer[i] == 0)
+							{
+								irqT[i] = true;
+								WritePortB((byte)(ReadPortB() | portBit[i]));
+							}
+						}
+						break;
+					case tControlContinuousPB:
+						if (timer[i] > 0)
+						{
+							timer[i]--;
+							if (timer[i] == 0)
+							{
+								irqT[i] = true;
+								timer[i] = timerLatch[i];
+								WritePortB((byte)(ReadPortB() ^ portBit[i]));
+							}
+						}
+						break;
+					case tControlPulseCounter:
+						if ((lastpb & 0x40) != 0 && (ReadPortB() & 0x40) == 0)
+						{
+							if (timer[i] > 0)
+							{
+								timer[i]--;
+								if (timer[i] == 0)
+								{
+									irqT[i] = true;
+								}
+							}
+						}
+						break;
+				}
+			}
+
+			lastca[0] = ca0;
+			lastca[1] = ca1;
+			lastcb[0] = cb0;
+			lastcb[1] = cb1;
+			lastpb = ReadPortB();
+
+			pinIRQ = !((irqCA[0] & enableIrqCA[0]) |
+				(irqCA[1] & enableIrqCA[1]) |
+				(irqCB[0] & enableIrqCB[0]) |
+				(irqCB[1] & enableIrqCB[1]) |
+				(irqSR & enableIrqSR) |
+				(irqT[0] & enableIrqT[0]) |
+				(irqT[1] & enableIrqT[1])
 				);
+
+			
 		}
 
 		// ------------------------------------
@@ -113,15 +325,26 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
 		public byte Read(ushort addr)
 		{
+
+			//Console.WriteLine("via R: reg" + C64Util.ToHex(addr, 4));
+			
 			addr &= 0xF;
 			switch (addr)
 			{
 				case 0x0:
+					irqCB[0] = false;
+					irqCB[1] = false;
+
 					if (pbLatchEnable)
 						return Port.ExternalWrite(pbLatch, ReadPortB(), ReadDirB());
 					else
 						return ReadPortB();
 				case 0x1:
+					if (pcrControlA[0] != pcrControlInNegativeIndep && pcrControlA[0] != pcrControlInPositiveIndep)
+						irqCA[0] = false;
+					if (pcrControlA[1] != pcrControlInNegativeIndep && pcrControlA[1] != pcrControlInPositiveIndep)
+						irqCA[1] = false;
+
 					if (paLatchEnable)
 						return Port.ExternalWrite(paLatch, ReadPortA(), ReadDirA());
 					else
@@ -168,7 +391,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 						(paLatchEnable ? 0x01 : 0x00) |
 						(pbLatchEnable ? 0x02 : 0x00) |
 						(byte)((srControl & 0x7) << 2) |
-						(byte)((tControl[1] & 0x1) << 5) |
+						(byte)((tControl[1] & 0x4) << 3) |
 						(byte)((tControl[0] & 0x3) << 6)
 						);
 				case 0xC:
@@ -207,14 +430,25 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
 		public void Write(ushort addr, byte val)
 		{
+			byte result;
+			bool intEnable;
+
+			//Console.WriteLine("via W: reg" + C64Util.ToHex(addr, 4) + " val" + C64Util.ToHex(val, 2));
+
 			addr &= 0xF;
 			switch (addr)
 			{
 				case 0x0:
+					irqCB[0] = false;
+					irqCB[1] = false;
 					pbOut = val;
 					WritePortB(val);
 					break;
 				case 0x1:
+					if (pcrControlA[0] != pcrControlInNegativeIndep && pcrControlA[0] != pcrControlInPositiveIndep)
+						irqCA[0] = false;
+					if (pcrControlA[1] != pcrControlInNegativeIndep && pcrControlA[1] != pcrControlInPositiveIndep)
+						irqCA[1] = false;
 					paOut = val;
 					WritePortA(val);
 					break;
@@ -240,6 +474,15 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 					timer[1] = timerLatch[1];
 					irqT[1] = false;
 					break;
+				case 0xE:
+					intEnable = ((val & 0x80) != 0);
+					result = ReadRegister(addr);
+					if (intEnable)
+						result |= val;
+					else
+						result &= (byte)(val ^ 0x7F);
+					WriteRegister(0xE, result);
+					break;
 				default:
 					WriteRegister(addr, val);
 					break;
@@ -293,7 +536,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 					paLatchEnable = ((val & 0x01) != 0);
 					pbLatchEnable = ((val & 0x02) != 0);
 					srControl = (((uint)val >> 2) & 0x7);
-					tControl[1] = (((uint)val >> 5) & 0x1);
+					tControl[1] = (((uint)val >> 3) & 0x4);
 					tControl[0] = (((uint)val >> 6) & 0x3);
 					break;
 				case 0xC:
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Timer.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Timer.cs
index acc77b2f57..1222fabc17 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Timer.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Timer.cs
@@ -15,14 +15,14 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		protected bool[] timerOn;
 		protected bool[] underflow;
 
-		public Func<byte> ReadDirA;
-		public Func<byte> ReadDirB;
-		public Func<byte> ReadPortA;
-		public Func<byte> ReadPortB;
-		public Action<byte> WriteDirA;
-		public Action<byte> WriteDirB;
-		public Action<byte> WritePortA;
-		public Action<byte> WritePortB;
+		public Func<byte> ReadDirA = (() => { return 0xFF; });
+		public Func<byte> ReadDirB = (() => { return 0xFF; });
+		public Func<byte> ReadPortA = (() => { return 0xFF; });
+		public Func<byte> ReadPortB = (() => { return 0xFF; });
+		public Action<byte> WriteDirA = ((byte val) => { });
+		public Action<byte> WriteDirB = ((byte val) => { });
+		public Action<byte> WritePortA = ((byte val) => { });
+		public Action<byte> WritePortB = ((byte val) => { });
 
 		public Timer()
 		{
@@ -34,6 +34,8 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
 		protected void HardResetInternal()
 		{
+			WriteDirA(0x00);
+			WriteDirB(0x00);
 			timer[0] = 0xFFFF;
 			timer[1] = 0xFFFF;
 			timerLatch[0] = timer[0];