Safe-keeping commit. Currently debugging emulation using FUSE tests.

4 files changed, 272 insertions, 208 deletions

diff --git a/src/Noddybox.Emulation.EightBit.Z80.Disassembler/Z80Disassembler.cs b/src/Noddybox.Emulation.EightBit.Z80.Disassembler/Z80Disassembler.cs
index cdb378d..438b962 100644
--- a/src/Noddybox.Emulation.EightBit.Z80.Disassembler/Z80Disassembler.cs
+++ b/src/Noddybox.Emulation.EightBit.Z80.Disassembler/Z80Disassembler.cs
@@ -16,6 +16,7 @@
 // Copyright (c) 2012 Ian Cowburn

 //

 using System;

+using System.Text;

 

 namespace Noddybox.Emulation.EightBit.Z80.Disassembler

 {

@@ -45,19 +46,28 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         #endregion

 

-        #region Private.  Some of these routines are to support the original C code.

+        #region Private routines to support the original C code.

 

         private byte Z80_Dis_FetchByte(ref ushort addr)

         {

-            return memory.Read(addr++);

+            byte b = memory.Read(addr++);

+

+            if (Hex.Length > 0)

+            {

+                Hex.Append(" ");

+            }

+

+            Hex.AppendFormat("{0:x2}", b);

+

+            return b;

         }

 

-        private ushort FetchWord(ref ushort addr)

+        private ushort Z80_Dis_FetchWord(ref ushort addr)

         {

             Register16 r = new Register16(0);

 

-            r.low = memory.Read(addr++);

-            r.high = memory.Read(addr++);

+            r.low = Z80_Dis_FetchByte(ref addr);

+            r.high = Z80_Dis_FetchByte(ref addr);

 

             return r.reg;

         }

@@ -65,15 +75,75 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         private string Opcode {get; set;}

         private string Argument {get; set;}

 

+        private StringBuilder Hex {get; set;}

+

         private void Z80_Dis_Set(string a, string b)

         {

             Opcode = a;

             Argument = b;

         }

 

+        private string PopString(string s, int count)

+        {

+            if (s.Length <= count)

+            {

+                return String.Empty;

+            }

+            else

+            {

+                return s.Substring(count);

+            }

+        }

+

+        private string Z80_Dis_Printf(string fmt, params object[] o)

+        {

+            StringBuilder sb = new StringBuilder();

+            int arg = 0;

+

+            while(fmt.Length > 0)

+            {

+                if (fmt[0] == '%')

+                {

+                    if (fmt[1] == 'd' || fmt[1] == 's')

+                    {

+                        sb.Append("{");

+                        sb.AppendFormat("{0}", arg++);

+                        sb.Append("}");

+                        fmt = PopString(fmt, 2);

+                    }

+                    else if (fmt.StartsWith("%.2x"))

+                    {

+                        sb.Append("{");

+                        sb.AppendFormat("{0}:x2", arg++);

+                        sb.Append("}");

+                        fmt = PopString(fmt, 4);

+                    }

+                    else if (fmt.StartsWith("%.4x"))

+                    {

+                        sb.Append("{");

+                        sb.AppendFormat("{0}:x4", arg++);

+                        sb.Append("}");

+                        fmt = PopString(fmt, 4);

+                    }

+                    else

+                    {

+                        sb.Append(fmt[0]);

+                        fmt = PopString(fmt, 1);

+                    }

+                }

+                else

+                {

+                    sb.Append(fmt[0]);

+                    fmt = PopString(fmt, 1);

+                }

+            }

+

+            return String.Format(sb.ToString(), o);

+        }

+

         #endregion

 

-        #region Disassembler functions.  This code pretty much pasted as-is from my original C version

+        #region Disassembler functions.  This code pretty much pasted as-is from my original C version, with support routines to help.

 

         /* ---------------------------------------- CB xx BYTE OPCODES

         */

@@ -178,7 +248,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             sbyte r;

 

-            r=(sbyte)Z80_Dis_FetchByte(z80,pc);

+            r=(sbyte)Z80_Dis_FetchByte(ref pc);

 

             if (r<0)

                 return String.Format("(ix-{0:x2})",-r);

@@ -206,37 +276,28 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             {

                 case 0:

                     return ("b");

-                    break;

                 case 1:

                     return ("c");

-                    break;

                 case 2:

                     return ("d");

-                    break;

                 case 3:

                     return ("e");

-                    break;

                 case 4:

                     return ("ixh");

-                    break;

                 case 5:

                     return ("ixl");

-                    break;

                 case 6:

-                    return (IX_RelStr(0, pc));

-                    break;

+                    return (IX_RelStr(0, ref pc));

                 case 7:

                     return ("a");

-                    break;

                 default:

                     return String.Format("BUG {0}", reg);

-                    break;

             }

         }

 

         private void DIS_DD_NOP(byte op, ref ushort pc)

         {

-            dis_opcode_z80[op](op, pc);

+            dis_opcode_z80[op](op, ref pc);

         }

 

         private void DIS_ADD_IX_BC(byte op, ref ushort pc)

@@ -251,14 +312,14 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_LD_IX_WORD(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("ld", Z80_Dis_Printf("ix,$%.4x", Z80_Dis_FetchWord(pc)));

+            Z80_Dis_Set("ld", Z80_Dis_Printf("ix,$%.4x", Z80_Dis_FetchWord(ref pc)));

         }

 

         private void DIS_LD_ADDR_IX(byte op, ref ushort pc)

         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("($%.4x),ix", w));

         }

 

@@ -279,7 +340,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_LD_IXH_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("ld", Z80_Dis_Printf("ixh,$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("ld", Z80_Dis_Printf("ixh,$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_ADD_IX_IX(byte op, ref ushort pc)

@@ -291,7 +352,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("ix,($%.4x)", w));

         }

 

@@ -312,17 +373,17 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_LD_IXL_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("ld", Z80_Dis_Printf("ixl,$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("ld", Z80_Dis_Printf("ixl,$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_INC_IIX(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("inc", Z80_Dis_Printf("%s", IX_RelStr(op, pc)));

+            Z80_Dis_Set("inc", Z80_Dis_Printf("%s", IX_RelStr(op, ref pc)));

         }

 

         private void DIS_DEC_IIX(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("dec", Z80_Dis_Printf("%s", IX_RelStr(op, pc)));

+            Z80_Dis_Set("dec", Z80_Dis_Printf("%s", IX_RelStr(op, ref pc)));

         }

 

         private void DIS_LD_IIX_BYTE(byte op, ref ushort pc)

@@ -330,8 +391,8 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             string rel;

             int b;

 

-            rel = IX_RelStr(op, pc);

-            b = Z80_Dis_FetchByte(pc);

+            rel = IX_RelStr(op, ref pc);

+            b = Z80_Dis_FetchByte(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("%s,$%.2x", rel, b));

         }

 

@@ -352,62 +413,62 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             /* IX can't be used as source and destination when reading z80ory

             */

             if (dest_r==6)

-                {

-                dest=XR8(dest_r,pc);

+            {

+                dest=XR8(dest_r, ref pc);

                 src=z80_dis_reg8[src_r];

-                }

+            }

             else if (((dest_r==4)||(dest_r==5))&&(src_r==6))

-                {

+            {

                 dest=z80_dis_reg8[dest_r];

-                src=XR8(src_r,pc);

-                }

+                src = XR8(src_r, ref pc);

+            }

             else

-                {

-                dest=XR8(dest_r,pc);

-                src=XR8(src_r,pc);

-                }

+            {

+                dest = XR8(dest_r, ref pc);

+                src = XR8(src_r, ref pc);

+            }

 

             Z80_Dis_Set("ld",Z80_Dis_Printf("%s,%s",dest,src));

         }

 

         private void DIS_XADD_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("add", Z80_Dis_Printf("a,%s", XR8((op % 8), pc)));

+            Z80_Dis_Set("add", Z80_Dis_Printf("a,%s", XR8((op % 8), ref pc)));

         }

 

         private void DIS_XADC_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("adc", Z80_Dis_Printf("a,%s", XR8((op % 8), pc)));

+            Z80_Dis_Set("adc", Z80_Dis_Printf("a,%s", XR8((op % 8), ref pc)));

         }

 

         private void DIS_XSUB_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("sub", Z80_Dis_Printf("a,%s", XR8((op % 8), pc)));

+            Z80_Dis_Set("sub", Z80_Dis_Printf("a,%s", XR8((op % 8), ref pc)));

         }

 

         private void DIS_XSBC_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("sbc", Z80_Dis_Printf("a,%s", XR8((op % 8), pc)));

+            Z80_Dis_Set("sbc", Z80_Dis_Printf("a,%s", XR8((op % 8), ref pc)));

         }

 

         private void DIS_XAND_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("and", Z80_Dis_Printf("%s", XR8((op % 8), pc)));

+            Z80_Dis_Set("and", Z80_Dis_Printf("%s", XR8((op % 8), ref pc)));

         }

 

         private void DIS_XXOR_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("xor", Z80_Dis_Printf("%s", XR8((op % 8), pc)));

+            Z80_Dis_Set("xor", Z80_Dis_Printf("%s", XR8((op % 8), ref pc)));

         }

 

         private void DIS_X_OR_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("or", Z80_Dis_Printf("%s", XR8((op % 8), pc)));

+            Z80_Dis_Set("or", Z80_Dis_Printf("%s", XR8((op % 8), ref pc)));

         }

 

         private void DIS_XCP_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("cp", Z80_Dis_Printf("%s", XR8((op % 8), pc)));

+            Z80_Dis_Set("cp", Z80_Dis_Printf("%s", XR8((op % 8), ref pc)));

         }

 

         private void DIS_POP_IX(byte op, ref ushort pc)

@@ -437,35 +498,35 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_DD_CB_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            cb_off = (sbyte)Z80_Dis_FetchByte(pc);

-            nop = Z80_Dis_FetchByte(pc);

-            dis_DD_CB_opcode[nop](nop, pc);

+            cb_off = (sbyte)Z80_Dis_FetchByte(ref pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_DD_CB_opcode[nop](nop, ref pc);

         }

 

         private void DIS_DD_DD_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_DD_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_DD_opcode[nop](nop, ref pc);

         }

 

         private void DIS_DD_ED_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_ED_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_ED_opcode[nop](nop, ref pc);

         }

 

         private void DIS_DD_FD_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_FD_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_FD_opcode[nop](nop, ref pc);

         }

 

 

@@ -479,10 +540,10 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("rlc", Z80_Dis_Printf("%s", IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("rlc", Z80_Dis_Printf("%s", IX_RelStrCB(op, ref pc)));

             else

             {

-                Z80_Dis_Set("rlc", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("rlc", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

             }

         }

 

@@ -493,9 +554,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("rrc", Z80_Dis_Printf("%s", IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("rrc", Z80_Dis_Printf("%s", IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("rrc", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("rrc", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_RL_IX(byte op, ref ushort pc)

@@ -505,9 +566,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("rl", Z80_Dis_Printf("%s", IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("rl", Z80_Dis_Printf("%s", IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("rl", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("rl", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_RR_IX(byte op, ref ushort pc)

@@ -517,9 +578,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("rr", Z80_Dis_Printf("%s", IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("rr", Z80_Dis_Printf("%s", IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("rr", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("rr", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SLA_IX(byte op, ref ushort pc)

@@ -529,9 +590,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("sla", Z80_Dis_Printf("%s", IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("sla", Z80_Dis_Printf("%s", IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("sla", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("sla", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SRA_IX(byte op, ref ushort pc)

@@ -541,9 +602,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("sra", Z80_Dis_Printf("%s", IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("sra", Z80_Dis_Printf("%s", IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("sra", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("sra", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SRL_IX(byte op, ref ushort pc)

@@ -553,9 +614,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("srl", Z80_Dis_Printf("%s", IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("srl", Z80_Dis_Printf("%s", IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("srl", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("srl", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SLL_IX(byte op, ref ushort pc)

@@ -565,9 +626,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("sll", Z80_Dis_Printf("%s", IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("sll", Z80_Dis_Printf("%s", IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("sll", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("sll", Z80_Dis_Printf("%s[%s]", IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_BIT_IX(byte op, ref ushort pc)

@@ -579,9 +640,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             bit = (op - 0x40) / 8;

 

             if (reg == 6)

-                Z80_Dis_Set("bit", Z80_Dis_Printf("%d,%s", bit, IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("bit", Z80_Dis_Printf("%d,%s", bit, IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("bit", Z80_Dis_Printf("%d,%s[%s]", bit, IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("bit", Z80_Dis_Printf("%d,%s[%s]", bit, IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_RES_IX(byte op, ref ushort pc)

@@ -593,9 +654,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             bit = (op - 0x80) / 8;

 

             if (reg == 6)

-                Z80_Dis_Set("res", Z80_Dis_Printf("%d,%s", bit, IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("res", Z80_Dis_Printf("%d,%s", bit, IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("res", Z80_Dis_Printf("%d,%s[%s]", bit, IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("res", Z80_Dis_Printf("%d,%s[%s]", bit, IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SET_IX(byte op, ref ushort pc)

@@ -607,9 +668,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             bit = (op - 0xc0) / 8;

 

             if (reg == 6)

-                Z80_Dis_Set("set", Z80_Dis_Printf("%d,%s", bit, IX_RelStrCB(op, pc)));

+                Z80_Dis_Set("set", Z80_Dis_Printf("%d,%s", bit, IX_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("set", Z80_Dis_Printf("%d,%s[%s]", bit, IX_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("set", Z80_Dis_Printf("%d,%s[%s]", bit, IX_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

 

@@ -622,28 +683,20 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             {

                 case 0:

                     return ("b");

-                    break;

                 case 1:

                     return ("c");

-                    break;

                 case 2:

                     return ("d");

-                    break;

                 case 3:

                     return ("e");

-                    break;

                 case 4:

                     return ("h");

-                    break;

                 case 5:

                     return ("l");

-                    break;

                 case 6:

                     return ("0");

-                    break;

                 case 7:

                     return ("a");

-                    break;

             }

 

             return "?";

@@ -675,7 +728,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("($%.4x),%s", w, z80_dis_reg16[(op - 0x40) / 16]));

         }

 

@@ -708,7 +761,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("%s,($%.4x)", z80_dis_reg16[(op - 0x40) / 16], w));

         }

 

@@ -840,7 +893,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             sbyte r;

 

-            r=(sbyte)Z80_Dis_FetchByte(z80,pc);

+            r=(sbyte)Z80_Dis_FetchByte(ref pc);

 

             if (r<0)

                 return String.Format("(iy-${0:x2})",-r);

@@ -868,37 +921,28 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             {

                 case 0:

                     return ("b");

-                    break;

                 case 1:

                     return ("c");

-                    break;

                 case 2:

                     return ("d");

-                    break;

                 case 3:

                     return ("e");

-                    break;

                 case 4:

                     return ("iyh");

-                    break;

                 case 5:

                     return ("iyl");

-                    break;

                 case 6:

-                    return (IY_RelStr(0, pc));

-                    break;

+                    return (IY_RelStr(0, ref pc));

                 case 7:

                     return ("a");

-                    break;

                 default:

                     return String.Format("BUG {0}", reg);

-                    break;

             }

         }

 

         private void DIS_FD_NOP(byte op, ref ushort pc)

         {

-            dis_opcode_z80[op](op, pc);

+            dis_opcode_z80[op](op, ref pc);

         }

 

         private void DIS_ADD_IY_BC(byte op, ref ushort pc)

@@ -913,14 +957,14 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_LD_IY_WORD(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("ld", Z80_Dis_Printf("iy,$%.4x", Z80_Dis_FetchWord(pc)));

+            Z80_Dis_Set("ld", Z80_Dis_Printf("iy,$%.4x", Z80_Dis_FetchWord(ref pc)));

         }

 

         private void DIS_LD_ADDR_IY(byte op, ref ushort pc)

         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("($%.4x),iy", w));

         }

 

@@ -941,7 +985,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_LD_IYH_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("ld", Z80_Dis_Printf("iyh,$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("ld", Z80_Dis_Printf("iyh,$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_ADD_IY_IY(byte op, ref ushort pc)

@@ -953,7 +997,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("iy,($%.4x)", w));

         }

 

@@ -974,17 +1018,17 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_LD_IYL_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("ld", Z80_Dis_Printf("iyl,$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("ld", Z80_Dis_Printf("iyl,$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_INC_IIY(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("inc", Z80_Dis_Printf("%s", IY_RelStr(op, pc)));

+            Z80_Dis_Set("inc", Z80_Dis_Printf("%s", IY_RelStr(op, ref pc)));

         }

 

         private void DIS_DEC_IIY(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("dec", Z80_Dis_Printf("%s", IY_RelStr(op, pc)));

+            Z80_Dis_Set("dec", Z80_Dis_Printf("%s", IY_RelStr(op, ref pc)));

         }

 

         private void DIS_LD_IIY_BYTE(byte op, ref ushort pc)

@@ -992,8 +1036,8 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             string rel;

             int b;

 

-            rel = IY_RelStr(op, pc);

-            b = Z80_Dis_FetchByte(pc);

+            rel = IY_RelStr(op, ref pc);

+            b = Z80_Dis_FetchByte(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("%s,$%.2x", rel, b));

         }

 

@@ -1015,18 +1059,18 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             */

             if (dest_r==6)

                 {

-                dest=YR8(z80,dest_r,pc);

+                dest=YR8(dest_r,ref pc);

                 src=z80_dis_reg8[src_r];

                 }

             else if (((dest_r==4)||(dest_r==5))&&(src_r==6))

                 {

                 dest=z80_dis_reg8[dest_r];

-                src=YR8(z80,src_r,pc);

+                src=YR8(src_r,ref pc);

                 }

             else

                 {

-                dest=YR8(z80,dest_r,pc);

-                src=YR8(z80,src_r,pc);

+                dest=YR8(dest_r,ref pc);

+                src = YR8(src_r, ref pc);

                 }

 

             Z80_Dis_Set("ld",Z80_Dis_Printf("%s,%s",dest,src));

@@ -1034,42 +1078,42 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_YADD_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("add", Z80_Dis_Printf("a,%s", YR8((op % 8), pc)));

+            Z80_Dis_Set("add", Z80_Dis_Printf("a,%s", YR8((op % 8), ref pc)));

         }

 

         private void DIS_YADC_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("adc", Z80_Dis_Printf("a,%s", YR8((op % 8), pc)));

+            Z80_Dis_Set("adc", Z80_Dis_Printf("a,%s", YR8((op % 8), ref pc)));

         }

 

         private void DIS_YSUB_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("sub", Z80_Dis_Printf("a,%s", YR8((op % 8), pc)));

+            Z80_Dis_Set("sub", Z80_Dis_Printf("a,%s", YR8((op % 8), ref pc)));

         }

 

         private void DIS_YSBC_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("sbc", Z80_Dis_Printf("a,%s", YR8((op % 8), pc)));

+            Z80_Dis_Set("sbc", Z80_Dis_Printf("a,%s", YR8((op % 8), ref pc)));

         }

 

         private void DIS_YAND_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("and", Z80_Dis_Printf("%s", YR8((op % 8), pc)));

+            Z80_Dis_Set("and", Z80_Dis_Printf("%s", YR8((op % 8), ref pc)));

         }

 

         private void DIS_YYOR_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("xor", Z80_Dis_Printf("%s", YR8((op % 8), pc)));

+            Z80_Dis_Set("xor", Z80_Dis_Printf("%s", YR8((op % 8), ref pc)));

         }

 

         private void DIS_Y_OR_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("or", Z80_Dis_Printf("%s", YR8((op % 8), pc)));

+            Z80_Dis_Set("or", Z80_Dis_Printf("%s", YR8((op % 8), ref pc)));

         }

 

         private void DIS_YCP_R8(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("cp", Z80_Dis_Printf("%s", YR8((op % 8), pc)));

+            Z80_Dis_Set("cp", Z80_Dis_Printf("%s", YR8((op % 8), ref pc)));

         }

 

         private void DIS_POP_IY(byte op, ref ushort pc)

@@ -1099,35 +1143,35 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_FD_CB_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            cb_off = (sbyte)Z80_Dis_FetchByte(pc);

-            nop = Z80_Dis_FetchByte(pc);

-            dis_FD_CB_opcode[nop](nop, pc);

+            cb_off = (sbyte)Z80_Dis_FetchByte(ref pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_FD_CB_opcode[nop](nop, ref pc);

         }

 

         private void DIS_FD_DD_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_DD_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_DD_opcode[nop](nop, ref pc);

         }

 

         private void DIS_FD_ED_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_ED_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_ED_opcode[nop](nop, ref pc);

         }

 

         private void DIS_FD_FD_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_FD_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_FD_opcode[nop](nop, ref pc);

         }

 

 

@@ -1141,9 +1185,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("rlc", Z80_Dis_Printf("%s", IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("rlc", Z80_Dis_Printf("%s", IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("rlc", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("rlc", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_RRC_IY(byte op, ref ushort pc)

@@ -1153,9 +1197,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("rrc", Z80_Dis_Printf("%s", IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("rrc", Z80_Dis_Printf("%s", IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("rrc", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("rrc", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_RL_IY(byte op, ref ushort pc)

@@ -1165,9 +1209,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("rl", Z80_Dis_Printf("%s", IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("rl", Z80_Dis_Printf("%s", IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("rl", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("rl", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_RR_IY(byte op, ref ushort pc)

@@ -1177,9 +1221,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("rr", Z80_Dis_Printf("%s", IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("rr", Z80_Dis_Printf("%s", IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("rr", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("rr", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SLA_IY(byte op, ref ushort pc)

@@ -1189,9 +1233,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("sla", Z80_Dis_Printf("%s", IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("sla", Z80_Dis_Printf("%s", IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("sla", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("sla", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SRA_IY(byte op, ref ushort pc)

@@ -1201,9 +1245,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("sra", Z80_Dis_Printf("%s", IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("sra", Z80_Dis_Printf("%s", IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("sra", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("sra", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SRL_IY(byte op, ref ushort pc)

@@ -1213,9 +1257,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("srl", Z80_Dis_Printf("%s", IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("srl", Z80_Dis_Printf("%s", IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("srl", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("srl", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SLL_IY(byte op, ref ushort pc)

@@ -1225,9 +1269,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             reg = (op % 8);

 

             if (reg == 6)

-                Z80_Dis_Set("sll", Z80_Dis_Printf("%s", IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("sll", Z80_Dis_Printf("%s", IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("sll", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("sll", Z80_Dis_Printf("%s[%s]", IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_BIT_IY(byte op, ref ushort pc)

@@ -1239,9 +1283,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             bit = (op - 0x40) / 8;

 

             if (reg == 6)

-                Z80_Dis_Set("bit", Z80_Dis_Printf("%d,%s", bit, IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("bit", Z80_Dis_Printf("%d,%s", bit, IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("bit", Z80_Dis_Printf("%d,%s[%s]", bit, IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("bit", Z80_Dis_Printf("%d,%s[%s]", bit, IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_RES_IY(byte op, ref ushort pc)

@@ -1253,9 +1297,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             bit = (op - 0x80) / 8;

 

             if (reg == 6)

-                Z80_Dis_Set("res", Z80_Dis_Printf("%d,%s", bit, IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("res", Z80_Dis_Printf("%d,%s", bit, IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("res", Z80_Dis_Printf("%d,%s[%s]", bit, IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("res", Z80_Dis_Printf("%d,%s[%s]", bit, IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

         private void DIS_SET_IY(byte op, ref ushort pc)

@@ -1267,9 +1311,9 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             bit = (op - 0xc0) / 8;

 

             if (reg == 6)

-                Z80_Dis_Set("set", Z80_Dis_Printf("%d,%s", bit, IY_RelStrCB(op, pc)));

+                Z80_Dis_Set("set", Z80_Dis_Printf("%d,%s", bit, IY_RelStrCB(op, ref pc)));

             else

-                Z80_Dis_Set("set", Z80_Dis_Printf("%d,%s[%s]", bit, IY_RelStrCB(op, pc), z80_dis_reg8[reg]));

+                Z80_Dis_Set("set", Z80_Dis_Printf("%d,%s[%s]", bit, IY_RelStrCB(op, ref pc), z80_dis_reg8[reg]));

         }

 

 

@@ -1285,7 +1329,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             string reg;

 

             reg = z80_dis_reg16[(op & 0x30) / 0x10];

-            Z80_Dis_Set("ld", Z80_Dis_Printf("%s,$%.4x", reg, Z80_Dis_FetchWord(pc)));

+            Z80_Dis_Set("ld", Z80_Dis_Printf("%s,$%.4x", reg, Z80_Dis_FetchWord(ref pc)));

         }

 

         private void DIS_LD_R16_A(byte op, ref ushort pc)

@@ -1325,7 +1369,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             string reg;

 

             reg = z80_dis_reg8[(op & 0x38) / 0x8];

-            Z80_Dis_Set("ld", Z80_Dis_Printf("%s,$%.2x", reg, Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("ld", Z80_Dis_Printf("%s,$%.2x", reg, Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_RLCA(byte op, ref ushort pc)

@@ -1371,7 +1415,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort n;

 

-            n = pc + (sbyte)memory.Read(pc) + 1;

+            n = (ushort)(pc + (sbyte)((memory.Read(pc) + 1)));

             pc++;

             Z80_Dis_Set("djnz", Z80_Dis_Printf("$%.4x", n));

         }

@@ -1385,7 +1429,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort n;

 

-            n = pc + (sbyte)memory.Read(pc) + 1;

+            n = (ushort)(pc + (sbyte)(memory.Read(pc) + 1));

             pc++;

             Z80_Dis_Set("jr", Z80_Dis_Printf("$%.4x", n));

         }

@@ -1401,7 +1445,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             ushort n;

 

             con = z80_dis_condition[(op - 0x20) / 8];

-            n = pc + (sbyte)memory.Read(pc) + 1;

+            n = (ushort)(pc + (sbyte)(memory.Read(pc) + 1));

             pc++;

             Z80_Dis_Set("jr", Z80_Dis_Printf("%s,$%.4x", con, n));

         }

@@ -1410,7 +1454,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("($%.4x),hl", w));

         }

 

@@ -1423,7 +1467,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("hl,($%.4x)", w));

         }

 

@@ -1436,7 +1480,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("($%.4x),a", w));

         }

 

@@ -1449,7 +1493,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("ld", Z80_Dis_Printf("a,($%.4x)", w));

         }

 

@@ -1551,7 +1595,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

             reg = z80_dis_reg16[(op - 0xc0) / 16];

 

-            if (!strcmp(reg, "sp"))

+            if (reg == "sp")

                 reg = "af";

 

             Z80_Dis_Set("pop", reg);

@@ -1561,7 +1605,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("jp", Z80_Dis_Printf("$%.4x", w));

         }

 

@@ -1571,7 +1615,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

             reg = z80_dis_reg16[(op - 0xc0) / 16];

 

-            if (!strcmp(reg, "sp"))

+            if (reg == "sp")

                 reg = "af";

 

             Z80_Dis_Set("push", reg);

@@ -1579,7 +1623,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_ADD_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("add", Z80_Dis_Printf("a,$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("add", Z80_Dis_Printf("a,$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_RST(byte op, ref ushort pc)

@@ -1600,17 +1644,17 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             string con;

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             con = z80_dis_condition[(op - 0xc0) / 8];

             Z80_Dis_Set("jp", Z80_Dis_Printf("%s,$%.4x", con, w));

         }

 

         private void DIS_CB_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_CB_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_CB_opcode[nop](nop, ref pc);

         }

 

         private void DIS_CALL_CO(byte op, ref ushort pc)

@@ -1618,7 +1662,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             string con;

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             con = z80_dis_condition[(op - 0xc0) / 8];

             Z80_Dis_Set("call", Z80_Dis_Printf("%s,$%.4x", con, w));

         }

@@ -1627,23 +1671,23 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
         {

             ushort w;

 

-            w = Z80_Dis_FetchWord(pc);

+            w = Z80_Dis_FetchWord(ref pc);

             Z80_Dis_Set("call", Z80_Dis_Printf("$%.4x", w));

         }

 

         private void DIS_ADC_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("adc", Z80_Dis_Printf("a,$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("adc", Z80_Dis_Printf("a,$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_OUT_BYTE_A(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("out", Z80_Dis_Printf("($%.2x),a", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("out", Z80_Dis_Printf("($%.2x),a", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_SUB_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("sub", Z80_Dis_Printf("a,$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("sub", Z80_Dis_Printf("a,$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_EXX(byte op, ref ushort pc)

@@ -1653,20 +1697,20 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_IN_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("in", Z80_Dis_Printf("a,($%.2x)", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("in", Z80_Dis_Printf("a,($%.2x)", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_DD_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_DD_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_DD_opcode[nop](nop, ref pc);

         }

 

         private void DIS_SBC_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("sbc", Z80_Dis_Printf("a,$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("sbc", Z80_Dis_Printf("a,$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

 

@@ -1677,7 +1721,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_AND_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("and", Z80_Dis_Printf("$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("and", Z80_Dis_Printf("$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_JP_HL(byte op, ref ushort pc)

@@ -1692,15 +1736,15 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_ED_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_ED_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_ED_opcode[nop](nop, ref pc);

         }

 

         private void DIS_XOR_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("xor", Z80_Dis_Printf("$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("xor", Z80_Dis_Printf("$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_DI(byte op, ref ushort pc)

@@ -1710,7 +1754,7 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_OR_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("or", Z80_Dis_Printf("$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("or", Z80_Dis_Printf("$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         private void DIS_LD_SP_HL(byte op, ref ushort pc)

@@ -1725,15 +1769,15 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         private void DIS_FD_DECODE(byte op, ref ushort pc)

         {

-            int nop;

+            byte nop;

 

-            nop = Z80_Dis_FetchByte(pc);

-            dis_FD_opcode[nop](nop, pc);

+            nop = Z80_Dis_FetchByte(ref pc);

+            dis_FD_opcode[nop](nop, ref pc);

         }

 

         private void DIS_CP_A_BYTE(byte op, ref ushort pc)

         {

-            Z80_Dis_Set("cp", Z80_Dis_Printf("$%.2x", Z80_Dis_FetchByte(pc)));

+            Z80_Dis_Set("cp", Z80_Dis_Printf("$%.2x", Z80_Dis_FetchByte(ref pc)));

         }

 

         #endregion

@@ -1746,6 +1790,8 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
             //

             Register16.Verify();

 

+            Hex = new StringBuilder();

+

             // Setup function tables

             //

             dis_CB_opcode = new disassemble[0x100]

@@ -2355,13 +2401,16 @@ namespace Noddybox.Emulation.EightBit.Z80.Disassembler
 

         public ushort Disassemble(ushort startAddress, out string address, out string opcode, out string hexdump)

         {

-            address = String.Empty;

-            opcode = String.Empty;

-            hexdump = String.Empty;

-            Opcode = String.Empty;

-            Argument = String.Empty;

+            address = String.Format("{0:X4}", startAddress);

+

+            byte op = Z80_Dis_FetchByte(ref startAddress);

+

+            Hex.Clear();

+

+            dis_opcode_z80[op](op, ref startAddress);

 

-            String.Format(address, "{0:X4}", address);

+            opcode = String.Format("{0} {1}", Opcode, Argument);

+            hexdump = Hex.ToString();

 

             return startAddress;

         }

diff --git a/src/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs b/src/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs
index a2e6fed..2da155e 100644
--- a/src/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs
+++ b/src/Noddybox.Emulation.EightBit.Z80/Z80Cpu.cs
@@ -242,7 +242,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                     }

                 }

 

-                if ((parity & 1) == 1)

+                if ((parity & 1) == 0)

                 {

                     p = Z80Flags.PV;

                 }

@@ -523,5 +523,15 @@ namespace Noddybox.Emulation.EightBit.Z80
         }

 

         #endregion

+

+        #region Object overrides

+

+        public override string ToString()

+        {

+            return String.Format("A={0:x2} BC={1:x4} DE={2:x4} HL={3:x4} F={4}\nPC={5:x4} SP={6:x4} IX={7:x4} IY={8:x4} AF'={9:x4} BC'={10:x4} DE'={11:x4} HL'={12:x4}\nI={13:x2} R={14:x2} IFF1={15} IFF2={16} IM={17} HALT={18}",

+                                    A, BC.reg, DE.reg, HL.reg, F, PC, SP, IX.reg, IY.reg, AF_.reg, BC_.reg, DE_.reg, HL_.reg, I, R, IFF1, IFF2, IM, HALT);

+        }

+

+        #endregion

     }

 }

diff --git a/src/Noddybox.Emulation.EightBit.Z80/Z80CpuBaseOpcodes.cs b/src/Noddybox.Emulation.EightBit.Z80/Z80CpuBaseOpcodes.cs
index bc09ce2..e0cc4e4 100644
--- a/src/Noddybox.Emulation.EightBit.Z80/Z80CpuBaseOpcodes.cs
+++ b/src/Noddybox.Emulation.EightBit.Z80/Z80CpuBaseOpcodes.cs
@@ -441,9 +441,13 @@ namespace Noddybox.Emulation.EightBit.Z80
 

             F = PSZtable[A]

                     | carry

-                    | nf |

-                    ((Z80Flags)(acc ^ A) & Z80Flags.HalfCarry)

+                    | nf

                     | H35table[A];

+

+            if (((A ^ acc) & 0x10) == 0x10)

+            {

+                F |= Z80Flags.HalfCarry;

+            }

         }

 

         #endregion

@@ -517,7 +521,7 @@ namespace Noddybox.Emulation.EightBit.Z80
             byte carry = (byte)(F & Z80Flags.Carry);

             F = (F & (Z80Flags.PV | Z80Flags.Sign | Z80Flags.Zero))

                      | (Z80Flags)Binary.ShiftRight(A, 7);

-            A = (byte)(Binary.ShiftRight(A, 1) | carry);

+            A = (byte)(Binary.ShiftLeft(A, 1) | carry);

             F |= H35table[A];

         }

 

diff --git a/src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs b/src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs
index f0256ba..22a6c98 100644
--- a/src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs
+++ b/src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs
@@ -141,7 +141,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                     break;

 

                 case 0x10:  // DJNZ

-                    if (--BC.high == 0)

+                    if (--BC.high != 0)

                     {

                         clock.Add(13);

                         JR();

@@ -279,7 +279,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                     break;

 

                 case 0x2a:  // LD HL,(nnnnn)

-                    clock.Add(7);

+                    clock.Add(16);

                     addr = FetchWord();

                     hl.low = memory.Read(addr);

                     hl.high = memory.Read((ushort)(addr + 1));

@@ -410,6 +410,7 @@ namespace Noddybox.Emulation.EightBit.Z80
 

                     F ^= Z80Flags.Carry;

                     ClearFlag(Z80Flags.Hidden);

+                    ClearFlag(Z80Flags.Neg);

                     SetFlag(H35table[A]);

                     break;

 

@@ -734,7 +735,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                 case 0x7e:  // LD A,(HL)

                     clock.Add(7);

                     addr = (ushort)(hl.reg + Offset());

-                    HL.low = memory.Read(addr);

+                    A = memory.Read(addr);

                     break;

 

                 case 0x7f:  // LD A,A