Development check-in.

7 files changed, 94 insertions, 193 deletions

diff --git a/Noddybox.Emulation.EightBit/IMemory.cs b/Noddybox.Emulation.EightBit/IMemory.cs
index ee41500..2aa63d9 100644
--- a/Noddybox.Emulation.EightBit/IMemory.cs
+++ b/Noddybox.Emulation.EightBit/IMemory.cs
@@ -15,8 +15,7 @@ using System.Windows.Shapes;
 namespace Noddybox.Emulation.EightBit

 {

     /// <summary>

-    /// Defines an interface for memory.  Note that ints are used rather than smaller unsigned types due to the pain of

-    /// doing boolean operations on anything else in C# without copious casting.

+    /// Defines an interface for memory.

     /// </summary>

     public interface IMemory

     {

@@ -24,14 +23,14 @@ namespace Noddybox.Emulation.EightBit
         /// Reads a byte at a given address.

         /// </summary>

         /// <param name="address">The address to read.</param>

-        /// <returns>The value at that address in the lower 8-bits.</returns>

-        int Read(int address); 

+        /// <returns>The value at that address.</returns>

+        byte Read(ushort address); 

 

         /// <summary>

         /// Writes a byte at a given address.

         /// </summary>

         /// <param name="address">The address to write to.</param>

-        /// <param name="value">The value to write.  Only the lower 8-bits are taken.</param>

-        void Write(int address, int value);

+        /// <param name="value">The value to write.</param>

+        void Write(ushort address, byte value);

     }

 }

diff --git a/Noddybox.Emulation.EightBit/IRegister16.cs b/Noddybox.Emulation.EightBit/IRegister16.cs
deleted file mode 100644
index 4356756..0000000
--- a/Noddybox.Emulation.EightBit/IRegister16.cs
+++ /dev/null
@@ -1,37 +0,0 @@
-//

-// Copyright (c) 2012 Ian Cowburn

-//

-using System;

-using System.Net;

-using System.Windows;

-using System.Windows.Controls;

-using System.Windows.Documents;

-using System.Windows.Ink;

-using System.Windows.Input;

-using System.Windows.Media;

-using System.Windows.Media.Animation;

-using System.Windows.Shapes;

-

-namespace Noddybox.Emulation.EightBit

-{

-    /// <summary>

-    /// Provides a common 8-bit register pattern, which is two 8-bit registers rolled into one.

-    /// </summary>

-    public interface IRegister16

-    {

-        /// <summary>

-        /// Get/set the low byte of the 16-bit register.

-        /// </summary>

-        byte Low {get; set;}

-

-        /// <summary>

-        /// Get/set the high byte of the 16-bit register.

-        /// </summary>

-        byte High {get; set;}

-

-        /// <summary>

-        /// Get/set the value of the 16-bit register.

-        /// </summary>

-        ushort Value {get; set;}

-    }

-}

diff --git a/Noddybox.Emulation.EightBit/Noddybox.Emulation.EightBit.csproj b/Noddybox.Emulation.EightBit/Noddybox.Emulation.EightBit.csproj
index 801adae..2136f3c 100644
--- a/Noddybox.Emulation.EightBit/Noddybox.Emulation.EightBit.csproj
+++ b/Noddybox.Emulation.EightBit/Noddybox.Emulation.EightBit.csproj
@@ -53,11 +53,8 @@
     <Compile Include="ICpu.cs" />

     <Compile Include="IDevice.cs" />

     <Compile Include="IMemory.cs" />

-    <Compile Include="IRegister16.cs" />

     <Compile Include="Properties\AssemblyInfo.cs" />

-    <Compile Include="Register16BigEndian.cs" />

-    <Compile Include="Register16Factory.cs" />

-    <Compile Include="Register16LittleEndian.cs" />

+    <Compile Include="Register16.cs" />

   </ItemGroup>

   <ItemGroup>

     <ProjectReference Include="..\Noddybox.Emulation\Noddybox.Emulation.csproj">

diff --git a/Noddybox.Emulation.EightBit/Register16.cs b/Noddybox.Emulation.EightBit/Register16.cs
new file mode 100644
index 0000000..06c9c01
--- /dev/null
+++ b/Noddybox.Emulation.EightBit/Register16.cs
@@ -0,0 +1,88 @@
+//

+// Copyright (c) 2012 Ian Cowburn

+//

+using System;

+using System.Runtime.InteropServices;

+

+namespace Noddybox.Emulation.EightBit

+{

+    /// <summary>

+    /// Provides a common 8-bit register pattern, which is two 8-bit registers rolled into one.

+    /// While this could be done at runtime using <see cref="BitConverter.IsLittleEndian"/> this

+    /// method was chosen for speed reasons; interfaces cannot define fields, which is sensible

+    /// enoough, but accessing fields directly would allow ref variables to be used with this type's

+    /// fields.

+    /// </summary>

+    [StructLayout(LayoutKind.Explicit)]

+    public struct Register16

+    {

+#if TARGET_IS_BIGENDIAN

+

+        /// <summary>

+        /// The 16-bit register.

+        /// </summary>

+        [FieldOffset(0)]

+        public ushort reg;

+

+        /// <summary>

+        /// The high 8-bits of the register.

+        /// </summary>

+        [FieldOffset(0)]

+        public byte high;

+

+        /// <summary>

+        /// The low 8-bits of the register.

+        /// </summary>

+        [FieldOffset(1)]

+        public byte low;

+

+#else

+

+        /// <summary>

+        /// The 16-bit register.

+        /// </summary>

+        [FieldOffset(0)]

+        public ushort reg;

+

+        /// <summary>

+        /// The low 8-bits of the register.

+        /// </summary>

+        [FieldOffset(0)]

+        public byte low;

+

+        /// <summary>

+        /// The high 8-bits of the register.

+        /// </summary>

+        [FieldOffset(1)]

+        public byte high;

+

+#endif

+

+        /// <summary>

+        /// Public constructor.  This is provided to stop the compiler complaining when you use the struct as it

+        /// doesn't realise that setting <see cref="reg"/> will also set <see cref="low"/> and <see cref="high"/>.

+        /// </summary>

+        /// <param name="val">The 16-bit value to assign.</param>

+        public Register16(ushort val)

+        {

+            high = 0;

+            low = 0;

+            reg = val;

+        }

+

+        /// <summary>

+        /// Used to verify the compile-time setting at runtime.

+        /// </summary>

+        public static void Verify()

+        {

+            Register16 r = new Register16(0);

+

+            r.reg = 0x1234;

+

+            if (r.low != 0x24 || r.high != 0x12)

+            {

+                throw new Exception("Compile time endian setting incorrect");

+            }

+        }

+    }

+}

diff --git a/Noddybox.Emulation.EightBit/Register16BigEndian.cs b/Noddybox.Emulation.EightBit/Register16BigEndian.cs
deleted file mode 100644
index e7a3780..0000000
--- a/Noddybox.Emulation.EightBit/Register16BigEndian.cs
+++ /dev/null
@@ -1,56 +0,0 @@
-//

-// Copyright (c) 2012 Ian Cowburn

-//

-using System;

-using System.Net;

-using System.Windows;

-using System.Windows.Controls;

-using System.Windows.Documents;

-using System.Windows.Ink;

-using System.Windows.Input;

-using System.Windows.Media;

-using System.Windows.Media.Animation;

-using System.Windows.Shapes;

-using System.Runtime.InteropServices;

-

-namespace Noddybox.Emulation.EightBit

-{

-    [StructLayout(LayoutKind.Explicit)]

-    public struct Register16BigEndian : IRegister16

-    {

-        #region Register fields

-

-        [FieldOffset(0)]

-        ushort reg;

-

-        [FieldOffset(1)]

-        byte low;

-

-        [FieldOffset(0)]

-        byte high;

-

-        #endregion

-

-        #region IRegister16 Members

-

-        public byte Low

-        {

-            get {return low;}

-            set {low = value;}

-        }

-

-        public byte High

-        {

-            get {return high;}

-            set {high = value;}

-        }

-

-        public ushort Value

-        {

-            get {return reg;}

-            set {reg = value;}

-        }

-

-        #endregion

-    }

-}

diff --git a/Noddybox.Emulation.EightBit/Register16Factory.cs b/Noddybox.Emulation.EightBit/Register16Factory.cs
deleted file mode 100644
index 249e668..0000000
--- a/Noddybox.Emulation.EightBit/Register16Factory.cs
+++ /dev/null
@@ -1,34 +0,0 @@
-//

-// Copyright (c) 2012 Ian Cowburn

-//

-using System;

-using System.Net;

-using System.Windows;

-using System.Windows.Controls;

-using System.Windows.Documents;

-using System.Windows.Ink;

-using System.Windows.Input;

-using System.Windows.Media;

-using System.Windows.Media.Animation;

-using System.Windows.Shapes;

-

-namespace Noddybox.Emulation.EightBit

-{

-    /// <summary>

-    /// Defines a common 16-bit register, which is two bytes which are separately addressable.

-    /// </summary>

-    public static class Register16Factory

-    {

-        public static IRegister16 Create()

-        {

-            if (BitConverter.IsLittleEndian)

-            {

-                return new Register16LittleEndian();

-            }

-            else

-            {

-                return new Register16BigEndian();

-            }

-        }

-    }

-}

diff --git a/Noddybox.Emulation.EightBit/Register16LittleEndian.cs b/Noddybox.Emulation.EightBit/Register16LittleEndian.cs
deleted file mode 100644
index ccecdaf..0000000
--- a/Noddybox.Emulation.EightBit/Register16LittleEndian.cs
+++ /dev/null
@@ -1,56 +0,0 @@
-//

-// Copyright (c) 2012 Ian Cowburn

-//

-using System;

-using System.Net;

-using System.Windows;

-using System.Windows.Controls;

-using System.Windows.Documents;

-using System.Windows.Ink;

-using System.Windows.Input;

-using System.Windows.Media;

-using System.Windows.Media.Animation;

-using System.Windows.Shapes;

-using System.Runtime.InteropServices;

-

-namespace Noddybox.Emulation.EightBit

-{

-    [StructLayout(LayoutKind.Explicit)]

-    public struct Register16LittleEndian : IRegister16

-    {

-        #region Register fields

-

-        [FieldOffset(0)]

-        ushort reg;

-

-        [FieldOffset(0)]

-        byte low;

-

-        [FieldOffset(1)]

-        byte high;

-

-        #endregion

-

-        #region IRegister16 Members

-

-        public byte Low

-        {

-            get {return low;}

-            set {low = value;}

-        }

-

-        public byte High

-        {

-            get {return high;}

-            set {high = value;}

-        }

-

-        public ushort Value

-        {

-            get {return reg;}

-            set {reg = value;}

-        }

-

-        #endregion

-    }

-}