diff --git a/EightBit/Processor.cs b/EightBit/Processor.cs
index d9d80c5..e12a384 100644
--- a/EightBit/Processor.cs
+++ b/EightBit/Processor.cs
@@ -163,37 +163,16 @@ namespace EightBit
 
         protected void OnWrittenMemory() => this.WrittenMemory?.Invoke(this, EventArgs.Empty);
 
-        protected void MemoryWrite(byte low, byte high)
-        {
-            this.Bus.Address.Assign(low, high);
-            this.MemoryWrite();
-        }
-
         protected void MemoryWrite(byte low, byte high, byte data)
         {
             this.Bus.Address.Assign(low, high);
-            this.Bus.Data = data;
-            this.MemoryWrite();
-        }
-
-        protected void MemoryWrite(ushort address, byte data)
-        {
-            this.Bus.Address.Word = address;
-            this.Bus.Data = data;
-            this.MemoryWrite();
+            this.MemoryWrite(data);
         }
 
         protected void MemoryWrite(Register16 address, byte data)
         {
             this.Bus.Address.Assign(address);
-            this.Bus.Data = data;
-            this.MemoryWrite();
-        }
-
-        protected void MemoryWrite(Register16 address)
-        {
-            this.Bus.Address.Assign(address);
-            this.MemoryWrite();
+            this.MemoryWrite(data);
         }
 
         protected void MemoryWrite(byte data)
@@ -212,12 +191,6 @@ namespace EightBit
             return this.MemoryRead();
         }
 
-        protected byte MemoryRead(ushort address)
-        {
-            this.Bus.Address.Word = address;
-            return this.MemoryRead();
-        }
-
         protected byte MemoryRead(Register16 address)
         {
             this.Bus.Address.Assign(address);
diff --git a/Intel8080/Intel8080.cs b/Intel8080/Intel8080.cs
index d07bd05..cb89fc8 100644
--- a/Intel8080/Intel8080.cs
+++ b/Intel8080/Intel8080.cs
@@ -628,7 +628,7 @@ namespace Intel8080
 
         private byte Increment(byte operand)
         {
-            var result = ++operand;
+            var result = operand; ++result;
             AdjustSZP(result);
             ClearBit(StatusBits.AC, LowNibble(result));
             return result;
@@ -636,7 +636,7 @@ namespace Intel8080
 
         private byte Decrement(byte operand)
         {
-            var result = --operand;
+            var result = operand; --result;
             AdjustSZP(result);
             SetBit(StatusBits.AC, LowNibble(result) != (byte)Mask.Four);
             return result;
@@ -657,12 +657,8 @@ namespace Intel8080
 
         protected sealed override void CallConditional(bool condition)
         {
-            this.FetchInto(this.MEMPTR);
-            if (condition)
-            {
-                this.Call();
-            }
-            else
+            base.CallConditional(condition);
+            if (!condition)
             {
                 this.Tick();
             }
@@ -670,12 +666,8 @@ namespace Intel8080
 
         protected sealed override void ReturnConditionalFlag(int flag)
         {
-            var condition = this.ConvertCondition(flag);
             this.Tick();
-            if (condition)
-            {
-                this.Return();
-            }
+            base.ReturnConditionalFlag(flag);
         }
 
         private Register16 Add(Register16 operand, Register16 value)
diff --git a/LR35902/LR35902.cs b/LR35902/LR35902.cs
index 921b5ad..2fa8aca 100644
--- a/LR35902/LR35902.cs
+++ b/LR35902/LR35902.cs
@@ -5,6 +5,7 @@
 namespace LR35902
 {
     using EightBit;
+    using System.Diagnostics;
 
     public sealed class LR35902 : IntelProcessor
     {
@@ -336,29 +337,34 @@ namespace LR35902
 
         private void Start() => this.Stopped = false;
 
-        private void MemoryUpdate(int ticks)
+        private void MemoryUpdate(int ticks = 1)
         {
+            Debug.Assert(ticks > 0, "Ticks must be greater than zero");
+            this.OnWritingMemory();
             this.LowerMWR();
                 this.LowerWR();
                     base.MemoryWrite();
                     this.TickMachine(ticks);
                 this.RaiseWR();
             this.RaiseMWR();
+            this.OnWrittenMemory();
         }
 
         protected override void MemoryWrite()
         {
-            this.MemoryUpdate(1);
+            this.MemoryUpdate();
         }
 
         protected override byte MemoryRead()
         {
+            this.OnReadingMemory();
             this.LowerMWR();
                 this.LowerRD();
                     _ = base.MemoryRead();
                     this.TickMachine();
                 this.RaiseRD();
             this.RaiseMWR();
+            this.OnReadMemory();
             return this.Bus.Data;
         }
 
@@ -863,7 +869,7 @@ namespace LR35902
                                     break;
                                 case 1: // CB prefix
                                     this._prefixCB = true;
-                                    this.Execute(this.FetchByte());
+                                    this.Execute(this.FetchInstruction());
                                     break;
                                 case 6: // DI
                                     this.DisableInterrupts();
@@ -1063,9 +1069,9 @@ namespace LR35902
 
         private byte RL(byte operand)
         {
-            this.F = ClearBit(this.F, StatusBits.NF | StatusBits.HC | StatusBits.ZF);
+            this.ClearBit(StatusBits.NF | StatusBits.HC | StatusBits.ZF);
             var carry = this.Carry();
-            this.F = SetBit(this.F, StatusBits.CF, operand & (byte)Bits.Bit7);
+            this.SetBit(StatusBits.CF, operand & (byte)Bits.Bit7);
             return (byte)((operand << 1) | (carry >> 4));   // CF at Bit4
         }
 
@@ -1146,13 +1152,13 @@ namespace LR35902
             this.SetBit(StatusBits.CF, this.Carry() != 0 || (updated & (int)Bits.Bit8) != 0);
             this.A = LowByte(updated);
 
-            this.F = AdjustZero(this.F, this.A);
+            this.AdjustZero(this.A);
         }
 
         protected override void CPL()
         {
             base.CPL();
-            this.F = SetBit(this.F, StatusBits.HC | StatusBits.NF);
+            this.SetBit(StatusBits.HC | StatusBits.NF);
         }
 
         private void SCF()
@@ -1164,7 +1170,7 @@ namespace LR35902
         private void CCF()
         {
             this.ClearBit(StatusBits.NF | StatusBits.HC);
-            this.ClearBit(StatusBits.CF, this.F & (byte)StatusBits.CF);
+            this.ClearBit(StatusBits.CF, this.Carry());
         }
 
         private void RetI()
diff --git a/Z80/Z80.cs b/Z80/Z80.cs
index 8459519..241e8df 100644
--- a/Z80/Z80.cs
+++ b/Z80/Z80.cs
@@ -1643,19 +1643,21 @@ namespace Z80
         private byte Increment(byte operand)
         {
             this.ClearBit(StatusBits.NF);
-            this.AdjustSZXY(++operand);
-            this.SetBit(StatusBits.VF, operand == (byte)Bits.Bit7);
-            this.ClearBit(StatusBits.HC, LowNibble(operand));
-            return operand;
+            var result = operand; ++result;
+            this.AdjustSZXY(result);
+            this.SetBit(StatusBits.VF, result == (byte)Bits.Bit7);
+            this.ClearBit(StatusBits.HC, LowNibble(result));
+            return result;
         }
 
         private byte Decrement(byte operand)
         {
             this.SetBit(StatusBits.NF);
             this.ClearBit(StatusBits.HC, LowNibble(operand));
-            this.AdjustSZXY(--operand);
-            this.SetBit(StatusBits.VF, operand == (byte)Mask.Seven);
-            return operand;
+            var result = operand; --result;
+            this.AdjustSZXY(result);
+            this.SetBit(StatusBits.VF, result == (byte)Mask.Seven);
+            return result;
         }
 
         private void RetN()
@@ -1681,12 +1683,8 @@ namespace Z80
 
         protected sealed override void ReturnConditionalFlag(int flag)
         {
-            var condition = this.ConvertCondition(flag);
             this.Tick();
-            if (condition)
-            {
-                this.Return();
-            }
+            base.ReturnConditionalFlag(flag);
         }
 
         private Register16 SBC(Register16 operand, Register16 value)