Port access in Intel processors is 16 rather than 8 bit addressed

EightBit/InputOutput.cs

@@ -6,8 +6,8 @@ namespace EightBit
 {
     public sealed class InputOutput
     {
-        private readonly byte[] _input = new byte[0x100];
-        private readonly byte[] _output = new byte[0x100];
+        private readonly byte[] _input = new byte[0x10000];
+        private readonly byte[] _output = new byte[0x10000];
 
         public event EventHandler<PortEventArgs>? ReadingPort;
 
@@ -17,11 +17,15 @@ namespace EightBit
 
         public event EventHandler<PortEventArgs>? WrittenPort;
 
-        public byte Read(byte port) => this.ReadInputPort(port);
+        public byte Read(ushort port) => this.ReadInputPort(port);
 
-        public void Write(byte port, byte value) => this.WriteOutputPort(port, value);
+        public byte Read(Register16 port) => this.Read(port.Word);
 
-        public byte ReadInputPort(byte port)
+        public void Write(ushort port, byte value) => this.WriteOutputPort(port, value);
+
+        public void Write(Register16 port, byte value) => this.Write(port.Word, value);
+
+        public byte ReadInputPort(ushort port)
         {
             ReadingPort?.Invoke(this, new PortEventArgs(port));
             var value = this._input[port];
@@ -29,11 +33,11 @@ namespace EightBit
             return value;
         }
 
-        public void WriteInputPort(byte port, byte value) => this._input[port] = value;
+        public void WriteInputPort(ushort port, byte value) => this._input[port] = value;
 
-        public byte ReadOutputPort(byte port) => this._output[port];
+        public byte ReadOutputPort(ushort port) => this._output[port];
 
-        public void WriteOutputPort(byte port, byte value)
+        public void WriteOutputPort(ushort port, byte value)
         {
             WritingPort?.Invoke(this, new PortEventArgs(port));
             this._output[port] = value;

EightBit/PortEventArgs.cs

@@ -4,8 +4,8 @@
 
 namespace EightBit
 {
-    public sealed class PortEventArgs(byte value) : EventArgs
+    public sealed class PortEventArgs(ushort value) : EventArgs
     {
-        public byte Port { get; } = value;
+        public ushort Port { get; } = value;
     }
 }

Intel8080/Intel8080.cs

@@ -773,7 +773,7 @@ namespace Intel8080
             this.WritePort();
         }
 
-        private void WritePort() => this.ports.Write(this.Bus.Address.Low, this.Bus.Data);
+        private void WritePort() => this.ports.Write(this.Bus.Address, this.Bus.Data);
 
         private byte ReadPort(byte port)
         {
@@ -781,6 +781,6 @@ namespace Intel8080
             return this.ReadPort();
         }
 
-        private byte ReadPort() => this.Bus.Data = this.ports.Read(this.Bus.Address.Low);
+        private byte ReadPort() => this.Bus.Data = this.ports.Read(this.Bus.Address);
     }
 }

Z80/Z80.HarteTest/Checker.cs

@@ -410,15 +410,14 @@
 
             foreach (var port in ports)
             {
-                var address = new Register16(port.Address).Low;
                 var value = port.Value;
                 if (port.Type == "r")
                 {
-                    cpu.Ports.WriteInputPort(address, value);
+                    cpu.Ports.WriteInputPort(port.Address, value);
                 }
                 else if (port.Type == "w")
                 {
-                    cpu.Ports.WriteOutputPort(address, value);
+                    cpu.Ports.WriteOutputPort(port.Address, value);
                 }
                 else
                 {

Z80/Z80.cs

@@ -2344,7 +2344,7 @@ namespace Z80
             this.Tick(2);
             this.LowerIORQ();
             this.LowerWR();
-            this.Ports.Write(this.Bus.Address.Low, this.Bus.Data);
+            this.Ports.Write(this.Bus.Address, this.Bus.Data);
             this.Tick();
             this.RaiseWR();
             this.RaiseIORQ();
@@ -2364,7 +2364,7 @@ namespace Z80
             this.Tick(2);
             this.LowerIORQ();
             this.LowerRD();
-            this.Bus.Data = this.Ports.Read(this.Bus.Address.Low);
+            this.Bus.Data = this.Ports.Read(this.Bus.Address);
             this.Tick();
             this.RaiseRD();
             this.RaiseIORQ();