Modernise some more c# code

Z80/Z80.Test/Board.cs

@@ -19,11 +19,11 @@ namespace Z80.Test
         public Board(Configuration configuration)
         {
             this.configuration = configuration;
-            this.ram = new Ram(0x10000);
-            this.ports = new InputOutput();
-            this.CPU = new Z80(this, this.ports);
-            this.disassembler = new Disassembler(this);
-            this.mapping = new MemoryMapping(this.ram, 0x0000, (ushort)Mask.Sixteen, AccessLevel.ReadWrite);
+            this.ram = new(0x10000);
+            this.ports = new();
+            this.CPU = new(this, this.ports);
+            this.disassembler = new(this);
+            this.mapping = new(this.ram, 0x0000, (ushort)Mask.Sixteen, AccessLevel.ReadWrite);
         }
 
         public Z80 CPU { get; }
@@ -81,7 +81,7 @@ namespace Z80.Test
             }
         }
 
-        private void CPU_ExecutingInstruction_CPM(object sender, System.EventArgs e)
+        private void CPU_ExecutingInstruction_CPM(object? sender, System.EventArgs e)
         {
             if (this.CPU.PC.High != 0)
             {
@@ -105,8 +105,8 @@ namespace Z80.Test
             }
         }
 
-        private void CPU_LoweredHALT(object sender, System.EventArgs e) => this.LowerPOWER();
+        private void CPU_LoweredHALT(object? sender, System.EventArgs e) => this.LowerPOWER();
 
-        private void CPU_ExecutingInstruction_Debug(object sender, System.EventArgs e) => System.Console.Error.WriteLine($"{EightBit.Disassembler.State(this.CPU)}\t{this.disassembler.Disassemble(this.CPU)}");
+        private void CPU_ExecutingInstruction_Debug(object? sender, System.EventArgs e) => System.Console.Error.WriteLine($"{EightBit.Disassembler.State(this.CPU)}\t{this.disassembler.Disassemble(this.CPU)}");
     }
 }

Z80/Z80.Test/Configuration.cs

@@ -14,9 +14,9 @@ namespace Z80.Test
 
         public bool DebugMode { get; set; } = false;
 
-        public Register16 LoadAddress { get; } = new Register16(0x100);
+        public Register16 LoadAddress { get; } = new(0x100);
 
-        public Register16 StartAddress { get; } = new Register16(0x100);
+        public Register16 StartAddress { get; } = new(0x100);
 
         public string RomDirectory { get; } = "roms";
 

Z80/Z80.Test/TestHarness.cs

@@ -7,16 +7,14 @@ namespace Z80.Test
     using System;
     using System.Diagnostics;
 
-    internal class TestHarness : IDisposable
+    internal class TestHarness(Configuration configuration) : IDisposable
     {
-        private readonly Stopwatch timer = new Stopwatch();
-        private readonly Board board;
+        private readonly Stopwatch timer = new();
+        private readonly Board board = new(configuration);
         private long totalCycles = 0;
 
         private bool disposed = false;
 
-        public TestHarness(Configuration configuration) => this.board = new Board(configuration);
-
         public void Dispose()
         {
             this.Dispose(true);

Z80/Z80.cs

@@ -118,13 +118,13 @@ namespace EightBit
 
         public override Register16 HL => this.registers[this.registerSet, (int)RegisterIndex.IndexHL];
 
-        public Register16 IX { get; } = new Register16(0xffff);
+        public Register16 IX { get; } = new(0xffff);
 
         public byte IXH { get => this.IX.High; set => this.IX.High = value; }
 
         public byte IXL { get => this.IX.Low; set => this.IX.Low = value; }
 
-        public Register16 IY { get; } = new Register16(0xffff);
+        public Register16 IY { get; } = new(0xffff);
 
         public byte IYH { get => this.IY.High; set => this.IY.High = value; }
 
@@ -410,7 +410,7 @@ namespace EightBit
             this.DisableInterrupts();
             this.IM = 0;
 
-            this.REFRESH = new RefreshRegister(0);
+            this.REFRESH = new(0);
             this.IV = (byte)Mask.Eight;
 
             this.ExxAF();