diff --git a/BizHawk.Emulation/Computers/Commodore64/C64.cs b/BizHawk.Emulation/Computers/Commodore64/C64.cs
index 416fa82776..60b70716a4 100644
--- a/BizHawk.Emulation/Computers/Commodore64/C64.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/C64.cs
@@ -117,6 +117,8 @@ namespace BizHawk.Emulation.Computers.Commodore64
 				LagCount++;
 			_frame++;
 
+			Console.WriteLine("CPUPC: " + C64Util.ToHex(board.cpu.PC, 4) + " 1541PC: " + C64Util.ToHex(disk.PC, 4));
+
 			CoreOutputComm.DriveLED = DriveLED;
 		}
 
diff --git a/BizHawk.Emulation/Computers/Commodore64/Disk/VIC1541.cs b/BizHawk.Emulation/Computers/Commodore64/Disk/VIC1541.cs
index f8e088ef52..e0f896708b 100644
--- a/BizHawk.Emulation/Computers/Commodore64/Disk/VIC1541.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/Disk/VIC1541.cs
@@ -64,11 +64,31 @@ namespace BizHawk.Emulation.Computers.Commodore64.Disk
 			WriteVia0 = board.pla.WriteVia0;
 			WriteVia1 = board.pla.WriteVia1;
 		}
+
+		public ushort PC
+		{
+			get
+			{
+				return board.cpu.PC;
+			}
+		}
 	}
 
 	// because the VIC1541 doesn't have bank switching like the system does,
 	// we simplify things by processing the rom bytes directly.
 
+	// note: when a byte is read, the drive mechanics will cause
+	// the V flag on the 6502 to be enabled
+
+	// note: 6502 IRQ is wired to both VIA0 and VIA1. the NMI
+	// pin is not connected to any other source and is always
+	// held low.
+
+	// note: there is a GATE ARRAY that directs the signal
+	// between different parts of the board. it is not emulated
+	// directly, we are actually performing all its functions
+	// within the motherboard class itself.
+
 	public class VIC1541Motherboard
 	{
 		public MOS6502X cpu;
@@ -182,8 +202,12 @@ namespace BizHawk.Emulation.Computers.Commodore64.Disk
 			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); });	
+			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)
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs
index 62aba11dd8..6eecc17646 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6510.cs
@@ -112,6 +112,14 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 
 		// ------------------------------------
 
+		public ushort PC
+		{
+			get
+			{
+				return cpu.PC;
+			}
+		}
+
 		public byte Peek(int addr)
 		{
 			if (addr == 0x0000)
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs
index d8f42ab0d7..38549aa0b6 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6522.cs
@@ -250,9 +250,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 						}
 						break;
 					case tControlLoadPB:
-						if (pbPulse[i])
-							pbPulse[i] = false;
-						else
+						if (!pbPulse[i])
 							WritePortB((byte)(ReadPortB() & portMask[i]));
 
 						if (timer[i] > 0)
@@ -261,7 +259,8 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 							if (timer[i] == 0)
 							{
 								irqT[i] = true;
-								WritePortB((byte)(ReadPortB() | portBit[i]));
+								if (irqT[i])
+									WritePortB((byte)(ReadPortB() | portBit[i]));
 							}
 						}
 						break;
@@ -401,7 +400,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 						(byte)((pcrControlB[0] & 0x2) << 3) |
 						(byte)((pcrControlB[1] & 0x3) << 5)
 						);
-				case 0xD:
+				case 0xD: //IFR
 					return (byte)(
 						(irqCA[1] ? 0x01 : 0x00) |
 						(irqCA[0] ? 0x02 : 0x00) |
@@ -412,7 +411,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 						(irqT[0] ? 0x40 : 0x00) |
 						(pinIRQ ? 0x00 : 0x80)
 						);
-				case 0xE:
+				case 0xE: //IER
 					return (byte)(
 						(enableIrqCA[1] ? 0x01 : 0x00) |
 						(enableIrqCA[0] ? 0x02 : 0x00) |
@@ -421,7 +420,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 						(enableIrqCB[0] ? 0x10 : 0x00) |
 						(enableIrqT[1] ? 0x20 : 0x00) |
 						(enableIrqT[0] ? 0x40 : 0x00) |
-						(0x80)
+						(0x00)
 						);
 				default:
 					return 0x00;
@@ -454,11 +453,11 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 					break;
 				case 0x2:
 					WriteDirB(val);
-					WritePortB(val);
+					WritePortB(pbOut);
 					break;
 				case 0x3:
 					WriteDirA(val);
-					WritePortA(val);
+					WritePortA(paOut);
 					break;
 				case 0x4:
 				case 0x6:
@@ -469,18 +468,20 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 					WriteRegister(0x4, ReadRegister(0x6));
 					WriteRegister(0x5, ReadRegister(0x7));
 					irqT[0] = false;
+					pbPulse[0] = false;
 					break;
 				case 0x9:
 					timer[1] = timerLatch[1];
 					irqT[1] = false;
+					pbPulse[1] = false;
 					break;
 				case 0xE:
 					intEnable = ((val & 0x80) != 0);
 					result = ReadRegister(addr);
 					if (intEnable)
-						result |= val;
+						result |= (byte)(val & 0x7F);
 					else
-						result &= (byte)(val ^ 0x7F);
+						result &= (byte)((val & 0x7F) ^ 0x7F);
 					WriteRegister(0xE, result);
 					break;
 				default:
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6526.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6526.cs
index 48a2ca41bd..3671af72df 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6526.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/MOS6526.cs
@@ -93,7 +93,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			todAlarm = new byte[4];
 
 			SetTodIn(chipRegion);
-			HardReset();
+			pinFlag = true;
 		}
 
 		// ------------------------------------
@@ -194,7 +194,6 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 			todPM = false;
 
 			pinCnt = false;
-			pinFlag = true;
 			pinPC = true;
 	}
 
@@ -248,7 +247,6 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 				{
 					uint t = timer[index];
 					bool u = false;
-
 					
 					{
 						switch (timerInMode[index])
diff --git a/BizHawk.Emulation/Computers/Commodore64/MOS/Port.cs b/BizHawk.Emulation/Computers/Commodore64/MOS/Port.cs
index 434806e4c9..4b26076e20 100644
--- a/BizHawk.Emulation/Computers/Commodore64/MOS/Port.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/MOS/Port.cs
@@ -10,7 +10,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		static public byte CPUWrite(byte latch, byte val, byte dir)
 		{
 			byte result;
-			result = (byte)(latch & (byte)(~dir & 0xFF));
+			result = (byte)(latch & (byte)(dir ^ 0xFF));
 			result |= (byte)(val & dir);
 			return result;
 		}
@@ -19,7 +19,7 @@ namespace BizHawk.Emulation.Computers.Commodore64.MOS
 		{
 			byte result;
 			result = (byte)(latch & dir);
-			result |= (byte)(val & (byte)(~dir & 0xFF));
+			result |= (byte)(val & (byte)(dir ^ 0xFF));
 			return result;
 		}