diff --git a/src/main/java/com/loomcom/lm6502/Cpu.java b/src/main/java/com/loomcom/lm6502/Cpu.java
index 1c47868..e4623e8 100644
--- a/src/main/java/com/loomcom/lm6502/Cpu.java
+++ b/src/main/java/com/loomcom/lm6502/Cpu.java
@@ -3,20 +3,20 @@ package com.loomcom.lm6502;
 /**
  * Main 6502 CPU Simulation.
  */
-public class Cpu {
+public class Cpu implements InstructionTable {
 
 	/* The Bus */
 	private Bus bus;
 
 	/* User Registers */
-	private int a;    // Accumulator
-	private int x;    // X index register
-	private int y;    // Y index register
+	private int a;  // Accumulator
+	private int x;  // X index register
+	private int y;  // Y index register
 
 	/* Internal Registers */
-	private int pc;   // Program Counter register
-	private int sp;   // Stack Pointer register
-	private int ir;   // Instruction register
+	private int pc;  // Program Counter register
+	private int sp;  // Stack Pointer register
+	private int ir;  // Instruction register
 
 	/**
 	 * Construct a new CPU.
@@ -48,5 +48,29 @@ public class Cpu {
 		ir = 0;
 	}
 
+	/**
+	 * Performs an individual machine cycle.
+	 */
+	public void step() {
+		// 1. Fetch memory
+		ir = bus.read(pc);
+
+		// 2. Decode the instruction and execute.
+
+		// x. Increment PC
+		incProgramCounter();
+	}
+
+	/*
+	 * Increment the PC, rolling over if necessary.
+	 */
+	private void incProgramCounter() {
+		if (pc == 0xffff) {
+			pc = 0;
+		} else {
+			++pc;
+		}
+	}
+
 }
 
diff --git a/src/main/java/com/loomcom/lm6502/InstructionTable.java b/src/main/java/com/loomcom/lm6502/InstructionTable.java
new file mode 100644
index 0000000..a6f41d7
--- /dev/null
+++ b/src/main/java/com/loomcom/lm6502/InstructionTable.java
@@ -0,0 +1,195 @@
+package com.loomcom.lm6502;
+
+public interface InstructionTable {
+
+	// Addressing mode Enumeration
+	public enum Mode {
+		ACC {
+			public String toString() {
+				return "Accumulator";
+			}
+		},
+
+		ABS {
+			public String toString() {
+				return "Absolute";
+			}
+    },
+
+		ABX {
+			public String toString() {
+				return "Absolute, X-indexed";
+			}
+    },
+
+		ABY {
+			public String toString() {
+				return "Absolute, Y-indexed";
+			}
+    },
+
+		IMM {
+			public String toString() {
+				return "Immediate";
+			}
+    },
+
+		IMP {
+			public String toString() {
+				return "Implied";
+			}
+    },
+
+		IND {
+			public String toString() {
+				return "Indirect";
+			}
+    },
+
+		XIN {
+			public String toString() {
+				return "X-indexed Indirect";
+			}
+    },
+
+		INY {
+			public String toString() {
+				return "Indirect, Y-indexedY";
+			}
+    },
+
+		REL {
+			public String toString() {
+				return "Relative";
+			}
+    },
+
+		ZPG {
+			public String toString() {
+				return "Zeropage";
+			}
+    },
+
+		ZPX {
+			public String toString() {
+				return "Zeropage, X-indexed";
+			}
+    },
+
+		ZPY {
+			public String toString() {
+				return "Zeropage, Y-indexed";
+			}
+    },
+
+		NUL {
+			public String toString() {
+				return "NULL";
+			}
+    }
+	}
+
+	// 6502 opcodes.  No 65C02 opcodes implemented.
+	public static final String[] opcodeNames = {
+    "BRK", "ORA",  null,  null,  null, "ORA", "ASL",  null,
+    "PHP", "ORA", "ASL",  null,  null, "ORA", "ASL",  null,
+    "BPL", "ORA",  null,  null,  null, "ORA", "ASL",  null,
+    "CLC", "ORA",  null,  null,  null, "ORA", "ASL",  null,
+    "JSR", "AND",  null,  null, "BIT", "AND", "ROL",  null,
+    "PLP", "AND", "ROL",  null, "BIT", "AND", "ROL",  null,
+    "BMI", "AND",  null,  null,  null, "AND", "ROL",  null,
+    "SEC", "AND",  null,  null,  null, "AND", "ROL",  null,
+    "RTI", "EOR",  null,  null,  null, "EOR", "LSR",  null,
+    "PHA", "EOR", "LSR",  null, "JMP", "EOR", "LSR",  null,
+    "BVC", "EOR",  null,  null,  null, "EOR", "LSR",  null,
+    "CLI", "EOR",  null,  null,  null, "EOR", "LSR",  null,
+    "RTS", "ADC",  null,  null,  null, "ADC", "ROR",  null,
+    "PLA", "ADC", "ROR",  null, "JMP", "ADC", "ROR",  null,
+    "BVS", "ADC",  null,  null,  null, "ADC", "ROR",  null,
+    "SEI", "ADC",  null,  null,  null, "ADC", "ROR",  null,
+    "BCS", "STA",  null,  null, "STY", "STA", "STX",  null,
+    "DEY",  null, "TXA",  null, "STY", "STA", "STX",  null,
+    "BCC", "STA",  null,  null, "STY", "STA", "STX",  null,
+    "TYA", "STA", "TXS",  null,  null, "STA",  null,  null,
+    "LDY", "LDA", "LDX",  null, "LDY", "LDA", "LDX",  null,
+    "TAY", "LDA", "TAX",  null, "LDY", "LDA", "LDX",  null,
+		 null, "LDA",  null,  null, "LDY", "LDA", "LDX",  null,
+    "CLV", "LDA", "TSX",  null, "LDY", "LDA", "LDX",  null,
+    "CPY", "CMP",  null,  null, "CPY", "CMP", "DEC",  null,
+    "INY", "CMP", "DEX",  null, "CPY", "CMP", "DEC",  null,
+    "BNE", "CMP",  null,  null,  null, "CMP", "DEC",  null,
+    "CLD", "CMP",  null,  null,  null, "CMP", "DEC",  null,
+    "CPX", "SBC",  null,  null, "CPX", "SBC", "INC",  null,
+    "INX", "SBC", "NOP",  null, "CPX", "SBC", "INC",  null,
+    "BEQ", "SBC",  null,  null,  null, "SBC", "INC",  null,
+    "SED", "SBC",  null,  null,  null, "SBC", "INC",  null
+	};
+
+	public static final Mode[] opcodeModes = {
+		Mode.IMP, Mode.XIN, Mode.NUL, Mode.NUL,   // 0x00-0x03
+		Mode.NUL, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0x04-0x07
+		Mode.IMP, Mode.IMM, Mode.ACC, Mode.NUL,   // 0x08-0x0b
+		Mode.NUL, Mode.ABS, Mode.ABS, Mode.NUL,   // 0x0c-0x0f
+		Mode.REL, Mode.INY, Mode.NUL, Mode.NUL,   // 0x10-0x13
+		Mode.NUL, Mode.ZPX, Mode.ZPX, Mode.NUL,   // 0x14-0x17
+		Mode.IMP, Mode.ABY, Mode.NUL, Mode.NUL,   // 0x18-0x1b
+		Mode.NUL, Mode.ABX, Mode.ABX, Mode.NUL,   // 0x1c-0x1f
+		Mode.ABS, Mode.XIN, Mode.NUL, Mode.NUL,   // 0x20-0x23
+		Mode.ZPG, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0x24-0x27
+		Mode.IMP, Mode.IMM, Mode.ACC, Mode.NUL,   // 0x28-0x2b
+		Mode.ABS, Mode.ABS, Mode.ABS, Mode.NUL,   // 0x2c-0x2f
+		Mode.REL, Mode.INY, Mode.NUL, Mode.NUL,   // 0x30-0x33
+		Mode.NUL, Mode.ZPX, Mode.ZPX, Mode.NUL,   // 0x34-0x37
+		Mode.IMP, Mode.ABY, Mode.NUL, Mode.NUL,   // 0x38-0x3b
+		Mode.NUL, Mode.ABX, Mode.ABX, Mode.NUL,   // 0x3c-0x3f
+		Mode.IMP, Mode.XIN, Mode.NUL, Mode.NUL,   // 0x40-0x43
+		Mode.NUL, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0x44-0x47
+		Mode.IMP, Mode.IMM, Mode.ACC, Mode.NUL,   // 0x48-0x4b
+		Mode.ABS, Mode.ABS, Mode.ABS, Mode.NUL,   // 0x4c-0x4f
+		Mode.REL, Mode.INY, Mode.NUL, Mode.NUL,   // 0x50-0x53
+		Mode.NUL, Mode.ZPX, Mode.ZPX, Mode.NUL,   // 0x54-0x57
+		Mode.IMP, Mode.ABY, Mode.NUL, Mode.NUL,   // 0x58-0x5b
+		Mode.NUL, Mode.ABX, Mode.ABX, Mode.NUL,   // 0x5c-0x5f
+		Mode.IMP, Mode.XIN, Mode.NUL, Mode.NUL,   // 0x60-0x63
+		Mode.NUL, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0x64-0x67
+		Mode.IMP, Mode.IMM, Mode.ACC, Mode.NUL,   // 0x68-0x6b
+		Mode.IND, Mode.ABS, Mode.ABS, Mode.NUL,   // 0x6c-0x6f
+		Mode.REL, Mode.INY, Mode.NUL, Mode.NUL,   // 0x70-0x73
+		Mode.NUL, Mode.ZPX, Mode.ZPX, Mode.NUL,   // 0x74-0x77
+		Mode.IMP, Mode.ABY, Mode.NUL, Mode.NUL,   // 0x78-0x7b
+		Mode.NUL, Mode.ABX, Mode.ABX, Mode.NUL,   // 0x7c-0x7f
+		Mode.REL, Mode.XIN, Mode.NUL, Mode.NUL,   // 0x80-0x83
+		Mode.ZPG, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0x84-0x87
+		Mode.IMP, Mode.NUL, Mode.IMP, Mode.NUL,   // 0x88-0x8b
+		Mode.ABS, Mode.ABS, Mode.ABS, Mode.NUL,   // 0x8c-0x8f
+		Mode.REL, Mode.INY, Mode.NUL, Mode.NUL,   // 0x90-0x93
+		Mode.ZPX, Mode.ZPX, Mode.ZPY, Mode.NUL,   // 0x94-0x97
+		Mode.IMP, Mode.ABX, Mode.IMP, Mode.NUL,   // 0x98-0x9b
+		Mode.NUL, Mode.ABY, Mode.NUL, Mode.NUL,   // 0x9c-0x9f
+		Mode.IMM, Mode.XIN, Mode.IMM, Mode.NUL,   // 0xa0-0xa3
+		Mode.ZPG, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0xa4-0xa7
+		Mode.IMP, Mode.IMM, Mode.IMP, Mode.NUL,   // 0xa8-0xab
+		Mode.ABS, Mode.ABS, Mode.ABS, Mode.NUL,   // 0xac-0xaf
+		Mode.NUL, Mode.INY, Mode.NUL, Mode.NUL,   // 0xb0-0xb3
+		Mode.ZPX, Mode.ZPX, Mode.ZPY, Mode.NUL,   // 0xb4-0xb7
+		Mode.IMP, Mode.ABX, Mode.IMP, Mode.NUL,   // 0xb8-0xbb
+		Mode.ABX, Mode.ABY, Mode.ABY, Mode.NUL,   // 0xbc-0xbf
+		Mode.IMM, Mode.XIN, Mode.NUL, Mode.NUL,   // 0xc0-0xc3
+		Mode.ZPG, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0xc4-0xc7
+		Mode.IMP, Mode.IMM, Mode.IMP, Mode.NUL,   // 0xc8-0xcb
+		Mode.ABS, Mode.ABS, Mode.ABS, Mode.NUL,   // 0xcc-0xcf
+		Mode.REL, Mode.INY, Mode.NUL, Mode.NUL,   // 0xd0-0xd3
+		Mode.NUL, Mode.ZPX, Mode.ZPX, Mode.NUL,   // 0xd4-0xd7
+		Mode.IMP, Mode.ABY, Mode.NUL, Mode.NUL,   // 0xd8-0xdb
+		Mode.NUL, Mode.ABX, Mode.ABX, Mode.NUL,   // 0xdc-0xdf
+		Mode.IMM, Mode.XIN, Mode.NUL, Mode.NUL,   // 0xe0-0xe3
+		Mode.ZPG, Mode.ZPG, Mode.ZPG, Mode.NUL,   // 0xe4-0xe7
+		Mode.IMP, Mode.IMM, Mode.IMP, Mode.NUL,   // 0xe8-0xeb
+		Mode.ABS, Mode.ABS, Mode.ABS, Mode.NUL,   // 0xec-0xef
+		Mode.REL, Mode.INY, Mode.NUL, Mode.NUL,   // 0xf0-0xf3
+		Mode.NUL, Mode.ZPX, Mode.ZPX, Mode.NUL,   // 0xf4-0xf7
+		Mode.IMP, Mode.ABY, Mode.NUL, Mode.NUL,   // 0xf8-0xfb
+		Mode.NUL, Mode.ABX, Mode.ABX, Mode.NUL     // 0xfc-0xff
+	};
+
+}
\ No newline at end of file
diff --git a/src/main/java/com/loomcom/lm6502/Profiler.java b/src/main/java/com/loomcom/lm6502/Profiler.java
index 82872d4..76514c5 100644
--- a/src/main/java/com/loomcom/lm6502/Profiler.java
+++ b/src/main/java/com/loomcom/lm6502/Profiler.java
@@ -9,8 +9,31 @@ import java.util.*;
 import com.loomcom.lm6502.devices.*;
 import com.loomcom.lm6502.exceptions.*;
 
-public class Profiler {
+public class Profiler implements InstructionTable {
+
+
 	public static void main(String[] args) {
+		// new Profiler().profileMemoryReads();
+
+		new Profiler().dumpOpCodes();
+	}
+
+	public void dumpOpCodes() {
+		for (int i = 0; i < 0x100; i++) {
+			String name = opcodeNames[i];
+			Mode mode = opcodeModes[i];
+
+			System.out.print(String.format("0x%02x: ", i));
+
+			if (name == null) {
+				System.out.println("n/a");
+			} else {
+				System.out.println(name + " (" + mode + ")");
+			}
+		}
+	}
+
+	public void profileMemoryReads() {
 
 		try {