From f96332b0913a8a365db73a1af3443c0e225a23d8 Mon Sep 17 00:00:00 2001
From: Ian C <ianc@noddybox.co.uk>
Date: Thu, 29 Dec 2011 00:17:13 +0000
Subject: Development check-in.

---
 Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs | 179 +++++++++++++++++++-----------
 1 file changed, 117 insertions(+), 62 deletions(-)

(limited to 'Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs')

diff --git a/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs b/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs
index d967bb9..1583ae0 100644
--- a/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs
+++ b/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs
@@ -1,4 +1,7 @@
-using System;
+//
+// Copyright (c) 2012 Ian Cowburn
+//
+using System;
 using System.Net;
 using System.Windows;
 using System.Windows.Controls;
@@ -22,13 +25,13 @@ namespace Noddybox.Emulation.EightBit.Z80
         private enum Z80Flags
         {
             None        = 0x00,
-            Carry       = 0x01,
-            Neg		    = 0x02,
-            PV		    = 0x04,
-            Hidden3	    = 0x08,
-            HalfCarry   = 0x10,
-            Hidden5     = 0x20,
-            Zero		= 0x40,
+            Carry       = 0x01,
+            Neg		    = 0x02,
+            PV		    = 0x04,
+            Hidden3	    = 0x08,
+            HalfCarry   = 0x10,
+            Hidden5     = 0x20,
+            Zero		= 0x40,
             Sign		= 0x80            
         };
 
@@ -38,11 +41,12 @@ namespace Noddybox.Emulation.EightBit.Z80
 
         // Lookup tables
         //
-        private Z80Flags[] PSZtable = new Z80Flags[512];
-        private Z80Flags[] SZtable = new Z80Flags[512];
-        private Z80Flags[] Ptable = new Z80Flags[512];
-        private Z80Flags[] Stable = new Z80Flags[512];
+        private Z80Flags[] PSZtable = new Z80Flags[512];
+        private Z80Flags[] SZtable = new Z80Flags[512];
+        private Z80Flags[] Ptable = new Z80Flags[512];
+        private Z80Flags[] Stable = new Z80Flags[512];
         private Z80Flags[] Ztable = new Z80Flags[512];
+        private Z80Flags[] H35table = new Z80Flags[256];
 
         // Machine accessors
         //
@@ -53,17 +57,14 @@ namespace Noddybox.Emulation.EightBit.Z80
         // Main registers
         //
         private byte        A;
-        private byte        F;
-        private byte        R;
-        private byte        IFF1;
-        private byte        IFF2;
+        private Z80Flags    F;
         private IRegister16 BC = Register16Factory.Create();
         private IRegister16 DE = Register16Factory.Create();
         private IRegister16 HL = Register16Factory.Create();
         private IRegister16 IX = Register16Factory.Create();
         private IRegister16 IY = Register16Factory.Create();
-        private IRegister16 SP = Register16Factory.Create();
-        private IRegister16 PC = Register16Factory.Create();
+        private ushort      SP;
+        private ushort      PC;
 
         // Alternate registers
         //
@@ -72,6 +73,15 @@ namespace Noddybox.Emulation.EightBit.Z80
         private IRegister16 DE_ = Register16Factory.Create();
         private IRegister16 HL_ = Register16Factory.Create();
 
+        // Auxilliary registers and flags
+        //
+        private byte        I;
+        private byte        R;
+        private bool        IFF1;
+        private bool        IFF2;
+        private int         IM;
+        private bool        HALT;
+
         #endregion
 
         #region ICpu Members
@@ -87,7 +97,29 @@ namespace Noddybox.Emulation.EightBit.Z80
 
         public void Reset()
         {
-            // TODO: Initial register settings.
+            PC = 0;
+            A = 0xff;
+            F = (Z80Flags)0xff;
+
+            BC.Value = 0xffff;
+            DE.Value = 0xffff;
+            HL.Value = 0xffff;
+            AF_.Value = 0xffff;
+            BC_.Value = 0xffff;
+            DE_.Value = 0xffff;
+            HL_.Value = 0xffff;
+
+            IX.Value = 0xffff;
+            IY.Value = 0xffff;
+
+            SP = 0xffff;
+
+            IFF1 = false;
+            IFF2 = false;
+            IM = 0;
+            I = 0;
+            R = 0;
+            HALT = false;
         }
 
         public void Step()
@@ -97,16 +129,23 @@ namespace Noddybox.Emulation.EightBit.Z80
 
         public void Run()
         {
-            // TODO: Run for a frame
+            while(!clock.FrameDone)
+            {
+                Step();
+            }
         }
 
         public void MaskableInterrupt(byte value)
         {
+            clock.Add(2);
+
             // TODO: INT
         }
 
         public void NonMaskableInterrupt(byte value)
         {
+            clock.Add(2);
+
             // TODO: NMI
         }
 
@@ -118,48 +157,64 @@ namespace Noddybox.Emulation.EightBit.Z80
         {
             // Setup lookup tables
             //
-            for(int f = 0; f < 256; f++)
-            {
-                Z80Flags p = Z80Flags.None;
-                Z80Flags z = Z80Flags.None;
-                Z80Flags s = Z80Flags.None;
-                int parity = 0;
-
-                for(int b=0; b < 8; b++)
-                {
-                    if ((f & (1<<b)) == (1<<b))
-                    {
-                        parity++;
-                    }
-                }
-
-                if ((parity & 1) == 1)
-                {
-                    p = Z80Flags.PV;
-                }
-
-                if (f == 0)
-                {
-                    z = Z80Flags.Zero;
-                }
-
-                if ((f & 0x80) == 0x80)
-                {
-                    s = Z80Flags.Sign;
-                }
-
-                Ptable[f] = p;
-                Stable[f] = s;
-                Ztable[f] = z;
-                SZtable[f] =z|s;
-                PSZtable[f] = z|s|p;
-
-                Ptable[f+256] = Ptable[f]|Z80Flags.Carry;
-                Stable[f+256] = Stable[f]|Z80Flags.Carry;
-                Ztable[f+256] = Ztable[f]|Z80Flags.Carry;
-                SZtable[f+256] = SZtable[f]|Z80Flags.Carry;
-                PSZtable[f+256] = PSZtable[f]|Z80Flags.Carry;
-            }
+            for(int f = 0; f < 256; f++)
+            {
+                Z80Flags p = Z80Flags.None;
+                Z80Flags z = Z80Flags.None;
+                Z80Flags s = Z80Flags.None;
+                Z80Flags h3 = Z80Flags.None;
+                Z80Flags h5 = Z80Flags.None;
+
+                int parity = 0;
+
+                for(int b=0; b < 8; b++)
+                {
+                    if ((f & (1<<b)) == (1<<b))
+                    {
+                        parity++;
+                    }
+                }
+
+                if ((parity & 1) == 1)
+                {
+                    p = Z80Flags.PV;
+                }
+
+                if (f == 0)
+                {
+                    z = Z80Flags.Zero;
+                }
+
+                if ((f & 0x80) == 0x80)
+                {
+                    s = Z80Flags.Sign;
+                }
+
+                if ((f & (int)Z80Flags.Hidden3) == (int)Z80Flags.Hidden3)
+                {
+                    h3 = Z80Flags.Hidden3;
+                }
+
+                if ((f & (int)Z80Flags.Hidden5) == (int)Z80Flags.Hidden5)
+                {
+                    h5 = Z80Flags.Hidden5;
+                }
+
+                Ptable[f] = p;
+                Stable[f] = s;
+                Ztable[f] = z;
+                SZtable[f] =z | s;
+                PSZtable[f] = z | s | p;
+                H35table[f] = h3 | h5;
+
+                Ptable[f+256] = Ptable[f] | Z80Flags.Carry;
+                Stable[f+256] = Stable[f] | Z80Flags.Carry;
+                Ztable[f+256] = Ztable[f] | Z80Flags.Carry;
+                SZtable[f+256] = SZtable[f] | Z80Flags.Carry;
+                PSZtable[f+256] = PSZtable[f] | Z80Flags.Carry;
+            }
+
+            Reset();
         }
 
         #endregion
-- 
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