diff --git a/MC6809/MC6809.Test/Board.cs b/MC6809/MC6809.Test/Board.cs
index ac1dd86..4154e14 100644
--- a/MC6809/MC6809.Test/Board.cs
+++ b/MC6809/MC6809.Test/Board.cs
@@ -91,7 +91,7 @@ namespace MC6809.Test
 
         public override void LowerPOWER()
         {
-            ////this.profiler.Generate();
+            ////this._profiler.Generate();
 
             this.ACIA.LowerPOWER();
             this.CPU.LowerPOWER();
@@ -135,8 +135,8 @@ namespace MC6809.Test
                 this.CPU.ExecutedInstruction += CPU_ExecutedInstruction_Termination;
             }
 
-            ////this.profiler.Enable();
-            ////this.profiler.EmitLine += this.Profiler_EmitLine;
+            ////this._profiler.Enable();
+            ////this._profiler.EmitLine += this.Profiler_EmitLine;
         }
 
         private void Board_ReadingByte(object? sender, EventArgs e)
@@ -163,7 +163,10 @@ namespace MC6809.Test
         {
             var cycles = e.Cycles;
             var disassembled = e.Source;
-            Console.Error.WriteLine(disassembled);
+
+            var proportion = (double)cycles / this._profiler.TotalCycles;
+
+            Console.Error.WriteLine($"[{proportion:P2}]:{disassembled}");
         }
 
         private void CPU_ExecutedInstruction_Termination(object? sender, EventArgs e)
diff --git a/MC6809/ProfileLineEventArgs.cs b/MC6809/ProfileLineEventArgs.cs
index 82a1fd0..edb6316 100644
--- a/MC6809/ProfileLineEventArgs.cs
+++ b/MC6809/ProfileLineEventArgs.cs
@@ -3,10 +3,10 @@
 // </copyright>
 namespace MC6809
 {
-    public class ProfileLineEventArgs(string source, ulong cycles) : EventArgs
+    public class ProfileLineEventArgs(string source, long cycles) : EventArgs
     {
         public string Source { get; } = source;
 
-        public ulong Cycles { get; } = cycles;
+        public long Cycles { get; } = cycles;
     }
 }
\ No newline at end of file
diff --git a/MC6809/Profiler.cs b/MC6809/Profiler.cs
index fac85ef..c66e493 100644
--- a/MC6809/Profiler.cs
+++ b/MC6809/Profiler.cs
@@ -3,19 +3,25 @@
 // </copyright>
 namespace MC6809
 {
+    using System.Diagnostics;
+
     using EightBit;
 
     public sealed class Profiler(Bus board, MC6809 processor, Disassembler disassembler)
     {
-        private readonly ulong[] instructionCounts = new ulong[0x10000];
-        private readonly ulong[] addressProfiles = new ulong[0x10000];
-        private readonly ulong[] addressCounts = new ulong[0x10000];
+        private readonly long[] instructionCounts = new long[0x10000];
+        private readonly long[] addressProfiles = new long[0x10000];
+        private readonly long[] addressCounts = new long[0x10000];
 
         private readonly Bus board = board;
         private readonly MC6809 processor = processor;
         private readonly Disassembler disassembler = disassembler;
 
-        private ushort address;
+        private ushort _executingAddress;
+
+        private long _totalCycles = -1;
+        private bool _totalCyclesValid;
+
 
         public event EventHandler<EventArgs>? StartingOutput;
 
@@ -27,6 +33,21 @@ namespace MC6809
 
         public event EventHandler<ProfileLineEventArgs>? EmitLine;
 
+        public long TotalCycles
+        {
+            get
+            {
+                Debug.Assert(this._totalCyclesValid);
+                return this._totalCycles;
+            }
+            private set
+            {
+                Debug.Assert(!this._totalCyclesValid);
+                this._totalCycles = value;
+                this._totalCyclesValid = true;
+            }
+        }
+
         public void Enable()
         {
             this.processor.ExecutingInstruction += this.Processor_ExecutingInstruction;
@@ -48,6 +69,8 @@ namespace MC6809
 
         private void EmitProfileInformation()
         {
+            this.TotalCycles = addressProfiles.Sum();
+
             this.OnStartingLineOutput();
             try
             {
@@ -73,21 +96,21 @@ namespace MC6809
             }
         }
 
-        private void Processor_ExecutingInstruction(object? sender, EventArgs e) => this.address = this.processor.PC.Joined;
+        private void Processor_ExecutingInstruction(object? sender, EventArgs e) => this._executingAddress = this.processor.PC.Joined;
 
         private void Processor_ExecutedInstruction(object? sender, EventArgs e)
         {
-            ushort opcode = this.board.Peek(this.address);
+            ushort opcode = this.board.Peek(this._executingAddress);
             if (opcode == 0x10 || opcode == 0x11)
             {
                 opcode *= 0x100;
-                opcode += this.board.Peek((ushort)(this.address + 1));
+                opcode += this.board.Peek((ushort)(this._executingAddress + 1));
             }
 
-            this.addressCounts[this.address]++;
+            this.addressCounts[this._executingAddress]++;
             this.instructionCounts[opcode]++;
 
-            this.addressProfiles[this.address] += (ulong)this.processor.Cycles;
+            this.addressProfiles[this._executingAddress] += this.processor.Cycles;
         }
 
         private void OnStartingOutput() => this.StartingOutput?.Invoke(this, EventArgs.Empty);
@@ -98,6 +121,6 @@ namespace MC6809
 
         private void OnFinishedLineOutput() => this.FinishedLineOutput?.Invoke(this, EventArgs.Empty);
 
-        private void OnEmitLine(string source, ulong cycles) => this.EmitLine?.Invoke(this, new ProfileLineEventArgs(source, cycles));
+        private void OnEmitLine(string source, long cycles) => this.EmitLine?.Invoke(this, new ProfileLineEventArgs(source, cycles));
     }
 }
\ No newline at end of file