Ejemplo n.º 1
0
        /// <summary>
        /// returns the length of the instruction
        /// </summary>
        /// <param name="data">ram</param>
        /// <param name="index">where to disassemble</param>
        /// <param name="dasm">dasm</param>
        /// <returns></returns>
        static int ParseInstruction(byte[] data, int index, DASMData dasm)
        {
            //copy the data into
            byte[] ir = new byte[5];

            for (int i = 0; i < 5; i++)
            {
                if (i + index >= data.Length)
                {
                    break;
                }

                ir[i] = data[i + index];
            }


            Decode(ir, dasm);
            GetOpCodeText(dasm);
            return(dasm.TotalBytes);
        }
Ejemplo n.º 2
0
        /// <summary>
        /// populates dasm with disassembly
        /// </summary>
        /// <param name="data"></param>
        /// <param name=""></param>
        public static void Disassemble(byte[] data, int index, List <string> lines)
        {
            List <Tuple <string, string> > statement = new List <Tuple <string, string> >();

            int len = 0;

            //get the 1st opcode btyte

            for (int i = 0; i < 30; i++)
            {
                DASMData dasm = new DASMData();
                len    = ParseInstruction(data, index, dasm);
                index += len;
                if (len == 0)
                {
                    break;
                }
                lines.Add(dasm.Text);
            }
        }
Ejemplo n.º 3
0
        /// <summary>
        /// returns the length
        /// </summary>
        /// <param name="ir"></param>
        /// <returns></returns>
        public static void Decode(byte[] ir, DASMData data)
        {
            byte x, y, z, p, q;

            //x is 2 highest bits
            x = (byte)(ir[0] & (byte)0xC0);

            x = (byte)(x >> 6);

            //y = bits 5,4,3
            y = (byte)(ir[0] & 0x38); /* 00111000 */
            y = (byte)(y >> 3);

            //z = lowest three bits
            z = (byte)(ir[0] & 0x07);

            /*p is bits 4,5*/
            p = (byte)(ir[0] & 0x30);
            p = (byte)(p >> 4);

            /*q = bit 3*/
            q = (byte)(ir[0] & 0x08);
            q = (byte)(q >> 3);

            if (IsPrefix(ir) == false)
            {//1 byte op code
                data.OpCode       = ir[0];
                data.OpCodeLength = 1;
                data.TotalBytes   = 1;

                if (HasImmediateByte(x, y, z))
                {
                    data.ImmediateByte1 = ir[1];
                    data.ImmediateSize  = 1;
                    data.TotalBytes     = 2;
                }
                else if (HasImmediateWord(p, q, x, y, z) == true)
                {
                    data.ImmediateWord = (ushort)(ir[1] * 256 + ir[2]);
                    data.OpCodeLength  = 1;
                    data.TotalBytes    = 3;
                }
                else
                {
                    data.ImmediateSize = 0;
                }
            }
            else
            {//is a prefix (2 byte opcode)
                data.OpCodeLength = 2;
                data.OpCode       = (ushort)(ir[0] * 256 + ir[1]);

                //how do we figure out if there's 0,1,or 2 immediates?
                if (PrefixedWithImmediateByte(ir))
                {//1 byte immediate
                    data.ImmediateByte1 = ir[2];
                    data.NumOperands    = 1;
                    data.ImmediateSize  = 1;
                    data.TotalBytes     = 3;
                }
                else if (PrefixedWith2ImmediateBytes(ir))
                {//2 immediates  (bit (ix+d),n)
                    data.ImmediateByte1 = ir[2];
                    data.ImmediateByte2 = ir[3];
                    data.NumOperands    = 2;
                    data.ImmediateSize  = 1;
                    data.TotalBytes     = 4;
                }
                else if (PrefixedWithImmediateWord(ir))
                {//2 immediates (ld ix,nn)
                    data.ImmediateByte1 = ir[2];
                    data.ImmediateByte2 = ir[3];
                    data.NumOperands    = 2;
                    data.ImmediateSize  = 1;
                    data.TotalBytes     = 4;
                }
                else
                {
                    data.TotalBytes    = 2;
                    data.NumOperands   = 0;
                    data.ImmediateSize = 0;
                }
            }
        }
Ejemplo n.º 4
0
        static bool GetOpCodeText(DASMData data, Dictionary <string, ushort> labels = null)
        {
            // r,r instructions (no immediates)
            if (data.OpCode == 0x00)
            {
                data.Text = "nop";
            }
            else if (data.OpCode == 0x86)
            {
                data.Text = "add a,(hl)";
            }
            else if (data.OpCode == 0x87)
            {
                data.Text = "add a,a";
            }
            else if (data.OpCode == 0x80)
            {
                data.Text = "add a,b";
            }
            else if (data.OpCode == 0x81)
            {
                data.Text = "add a,c";
            }
            else if (data.OpCode == 0x82)
            {
                data.Text = "add a,d";
            }
            else if (data.OpCode == 0x83)
            {
                data.Text = "add a,e";
            }
            else if (data.OpCode == 0x84)
            {
                data.Text = "add a,h";
            }
            else if (data.OpCode == 0x85)
            {
                data.Text = "add a,l";
            }

            else if (data.OpCode == 0x09)
            {
                data.Text = "add hl,bc";
            }
            else if (data.OpCode == 0x19)
            {
                data.Text = "add hl,de";
            }
            else if (data.OpCode == 0x29)
            {
                data.Text = "add hl,hl";
            }
            else if (data.OpCode == 0x39)
            {
                data.Text = "add hl,sp";
            }

            else if (data.OpCode == 0xA6)
            {
                data.Text = "and a,(hl)";
            }
            else if (data.OpCode == 0xA7)
            {
                data.Text = "and a,a";
            }
            else if (data.OpCode == 0xA0)
            {
                data.Text = "and a,b";
            }
            else if (data.OpCode == 0xA1)
            {
                data.Text = "and a,c";
            }
            else if (data.OpCode == 0xA2)
            {
                data.Text = "and a,d";
            }
            else if (data.OpCode == 0xA3)
            {
                data.Text = "and a,e";
            }
            else if (data.OpCode == 0xA4)
            {
                data.Text = "and a,h";
            }
            else if (data.OpCode == 0xA5)
            {
                data.Text = "and a,l";
            }

            else if (data.OpCode == 0xBE)
            {
                data.Text = "cp (hl)";
            }
            else if (data.OpCode == 0xBF)
            {
                data.Text = "cp a";
            }
            else if (data.OpCode == 0xB8)
            {
                data.Text = "cp b";
            }
            else if (data.OpCode == 0xB9)
            {
                data.Text = "cp c";
            }
            else if (data.OpCode == 0xBA)
            {
                data.Text = "cp d";
            }
            else if (data.OpCode == 0xBB)
            {
                data.Text = "cp e";
            }
            else if (data.OpCode == 0xBC)
            {
                data.Text = "cp h";
            }
            else if (data.OpCode == 0xBD)
            {
                data.Text = "cp l";
            }

            else if (data.OpCode == 0x2F)
            {
                data.Text = "cpl";
            }

            else if (data.OpCode == 0x35)
            {
                data.Text = "dec (hl)";
            }
            else if (data.OpCode == 0x3D)
            {
                data.Text = "dec a";
            }
            else if (data.OpCode == 0x05)
            {
                data.Text = "dec b";
            }
            else if (data.OpCode == 0x0B)
            {
                data.Text = "dec bc";
            }
            else if (data.OpCode == 0x0D)
            {
                data.Text = "dec c";
            }
            else if (data.OpCode == 0x15)
            {
                data.Text = "dec d";
            }
            else if (data.OpCode == 0x1B)
            {
                data.Text = "dec de";
            }
            else if (data.OpCode == 0x1D)
            {
                data.Text = "dec e";
            }
            else if (data.OpCode == 0x25)
            {
                data.Text = "dec h";
            }
            else if (data.OpCode == 0x2B)
            {
                data.Text = "dec hl";
            }
            else if (data.OpCode == 0x2D)
            {
                data.Text = "dec l";
            }
            else if (data.OpCode == 0x3B)
            {
                data.Text = "dec sp";
            }

            else if (data.OpCode == 0x34)
            {
                data.Text = "inc (hl)";
            }
            else if (data.OpCode == 0x3C)
            {
                data.Text = "inc a";
            }
            else if (data.OpCode == 0x04)
            {
                data.Text = "inc b";
            }
            else if (data.OpCode == 0x03)
            {
                data.Text = "inc bc";
            }
            else if (data.OpCode == 0x0C)
            {
                data.Text = "inc c";
            }
            else if (data.OpCode == 0x14)
            {
                data.Text = "inc d";
            }
            else if (data.OpCode == 0x13)
            {
                data.Text = "inc de";
            }
            else if (data.OpCode == 0x1c)
            {
                data.Text = "inc e";
            }
            else if (data.OpCode == 0x24)
            {
                data.Text = "inc h";
            }
            else if (data.OpCode == 0x23)
            {
                data.Text = "inc hl";
            }
            else if (data.OpCode == 0x2c)
            {
                data.Text = "inc l";
            }
            else if (data.OpCode == 0x33)
            {
                data.Text = "inc sp";
            }

            else if (data.OpCode == 0xE9)
            {
                data.Text = "jp (hl)";
            }

            else if (data.OpCode == 0x02)
            {
                data.Text = "ld (bc),a";
            }
            else if (data.OpCode == 0x12)
            {
                data.Text = "ld (de),a";
            }
            else if (data.OpCode == 0x77)
            {
                data.Text = "ld (hl),a";
            }
            else if (data.OpCode == 0x70)
            {
                data.Text = "ld (hl),b";
            }
            else if (data.OpCode == 0x71)
            {
                data.Text = "ld (hl),c";
            }
            else if (data.OpCode == 0x72)
            {
                data.Text = "ld (hl),d";
            }
            else if (data.OpCode == 0x73)
            {
                data.Text = "ld (hl),e";
            }
            else if (data.OpCode == 0x74)
            {
                data.Text = "ld (hl),h";
            }
            else if (data.OpCode == 0x75)
            {
                data.Text = "ld (hl),l";
            }

            else if (data.OpCode == 0x02)
            {
                data.Text = "ld (bc),a";
            }
            else if (data.OpCode == 0x12)
            {
                data.Text = "ld (de),a";
            }
            else if (data.OpCode == 0x77)
            {
                data.Text = "ld (hl),a";
            }
            else if (data.OpCode == 0x70)
            {
                data.Text = "ld (hl),b";
            }
            else if (data.OpCode == 0x71)
            {
                data.Text = "ld (hl),c";
            }
            else if (data.OpCode == 0x72)
            {
                data.Text = "ld (hl),d";
            }
            else if (data.OpCode == 0x73)
            {
                data.Text = "ld (hl),e";
            }
            else if (data.OpCode == 0x74)
            {
                data.Text = "ld (hl),h";
            }
            else if (data.OpCode == 0x75)
            {
                data.Text = "ld (hl),l";
            }

            else if (data.OpCode == 0x0A)
            {
                data.Text = "ld a,(bc)";
            }
            else if (data.OpCode == 0x1A)
            {
                data.Text = "ld a,(de)";
            }
            else if (data.OpCode == 0x7E)
            {
                data.Text = "ld a,(hl)";
            }

            else if (data.OpCode == 0x7F)
            {
                data.Text = "ld a,a";
            }
            else if (data.OpCode == 0x78)
            {
                data.Text = "ld a,b";
            }
            else if (data.OpCode == 0x79)
            {
                data.Text = "ld a,c";
            }
            else if (data.OpCode == 0x7A)
            {
                data.Text = "ld a,d";
            }
            else if (data.OpCode == 0x7B)
            {
                data.Text = "ld a,e";
            }
            else if (data.OpCode == 0x7C)
            {
                data.Text = "ld a,h";
            }
            else if (data.OpCode == 0x7D)
            {
                data.Text = "ld a,l";
            }
            // ld b,r
            else if (data.OpCode == 0x47)
            {
                data.Text = "ld b,a";
            }
            else if (data.OpCode == 0x40)
            {
                data.Text = "ld b,b";
            }
            else if (data.OpCode == 0x41)
            {
                data.Text = "ld b,c";
            }
            else if (data.OpCode == 0x42)
            {
                data.Text = "ld b,d";
            }
            else if (data.OpCode == 0x43)
            {
                data.Text = "ld b,e";
            }
            else if (data.OpCode == 0x44)
            {
                data.Text = "ld b,h";
            }
            else if (data.OpCode == 0x45)
            {
                data.Text = "ld b,l";
            }
            else if (data.OpCode == 0x46)
            {
                data.Text = "ld b,(hl)";
            }
            //ld c,r
            else if (data.OpCode == 0x4f)
            {
                data.Text = "ld c,a";
            }
            else if (data.OpCode == 0x48)
            {
                data.Text = "ld c,b";
            }
            else if (data.OpCode == 0x49)
            {
                data.Text = "ld c,c";
            }
            else if (data.OpCode == 0x4a)
            {
                data.Text = "ld c,d";
            }
            else if (data.OpCode == 0x4b)
            {
                data.Text = "ld c,e";
            }
            else if (data.OpCode == 0x4c)
            {
                data.Text = "ld c,h";
            }
            else if (data.OpCode == 0x4d)
            {
                data.Text = "ld c,l";
            }
            else if (data.OpCode == 0x4e)
            {
                data.Text = "ld c,(hl)";
            }
            //ld d,r
            else if (data.OpCode == 0x57)
            {
                data.Text = "ld d,a";
            }
            else if (data.OpCode == 0x50)
            {
                data.Text = "ld d,b";
            }
            else if (data.OpCode == 0x51)
            {
                data.Text = "ld d,c";
            }
            else if (data.OpCode == 0x52)
            {
                data.Text = "ld d,d";
            }
            else if (data.OpCode == 0x53)
            {
                data.Text = "ld d,e";
            }
            else if (data.OpCode == 0x54)
            {
                data.Text = "ld d,h";
            }
            else if (data.OpCode == 0x55)
            {
                data.Text = "ld d,l";
            }
            else if (data.OpCode == 0x56)
            {
                data.Text = "ld d,(hl)";
            }
            //ld e,r
            else if (data.OpCode == 0x5F)
            {
                data.Text = "ld e,a";
            }
            else if (data.OpCode == 0x58)
            {
                data.Text = "ld e,b";
            }
            else if (data.OpCode == 0x59)
            {
                data.Text = "ld e,c";
            }
            else if (data.OpCode == 0x5A)
            {
                data.Text = "ld e,d";
            }
            else if (data.OpCode == 0x5B)
            {
                data.Text = "ld e,e";
            }
            else if (data.OpCode == 0x5C)
            {
                data.Text = "ld e,h";
            }
            else if (data.OpCode == 0x5D)
            {
                data.Text = "ld e,l";
            }
            else if (data.OpCode == 0x5E)
            {
                data.Text = "ld e,(hl)";
            }
            //ld h,r
            else if (data.OpCode == 0x67)
            {
                data.Text = "ld h,a";
            }
            else if (data.OpCode == 0x60)
            {
                data.Text = "ld h,b";
            }
            else if (data.OpCode == 0x61)
            {
                data.Text = "ld h,c";
            }
            else if (data.OpCode == 0x62)
            {
                data.Text = "ld h,d";
            }
            else if (data.OpCode == 0x63)
            {
                data.Text = "ld h,e";
            }
            else if (data.OpCode == 0x64)
            {
                data.Text = "ld h,h";
            }
            else if (data.OpCode == 0x65)
            {
                data.Text = "ld h,l";
            }
            else if (data.OpCode == 0x66)
            {
                data.Text = "ld h,(hl)";
            }
            //ld l,r
            else if (data.OpCode == 0x6F)
            {
                data.Text = "ld l,a";
            }
            else if (data.OpCode == 0x68)
            {
                data.Text = "ld l,b";
            }
            else if (data.OpCode == 0x69)
            {
                data.Text = "ld l,c";
            }
            else if (data.OpCode == 0x6A)
            {
                data.Text = "ld l,d";
            }
            else if (data.OpCode == 0x6B)
            {
                data.Text = "ld l,e";
            }
            else if (data.OpCode == 0x6C)
            {
                data.Text = "ld l,h";
            }
            else if (data.OpCode == 0x6D)
            {
                data.Text = "ld l,l";
            }
            else if (data.OpCode == 0x6E)
            {
                data.Text = "ld l,(hl)";
            }

            //or r,r
            else if (data.OpCode == 0xB7)
            {
                data.Text = "ld l,a";
            }
            else if (data.OpCode == 0xB0)
            {
                data.Text = "ld l,b";
            }
            else if (data.OpCode == 0xB1)
            {
                data.Text = "ld l,c";
            }
            else if (data.OpCode == 0xB2)
            {
                data.Text = "ld l,d";
            }
            else if (data.OpCode == 0xB3)
            {
                data.Text = "ld l,e";
            }
            else if (data.OpCode == 0xB4)
            {
                data.Text = "ld l,h";
            }
            else if (data.OpCode == 0xB5)
            {
                data.Text = "ld l,l";
            }
            else if (data.OpCode == 0xB6)
            {
                data.Text = "or (hl)";
            }

            else if (data.OpCode == 0xF1)
            {
                data.Text = "pop af";
            }
            else if (data.OpCode == 0xC1)
            {
                data.Text = "pop bc";
            }
            else if (data.OpCode == 0xD1)
            {
                data.Text = "pop de";
            }
            else if (data.OpCode == 0xE1)
            {
                data.Text = "pop hl";
            }

            else if (data.OpCode == 0xF5)
            {
                data.Text = "push af";
            }
            else if (data.OpCode == 0xC5)
            {
                data.Text = "push bc";
            }
            else if (data.OpCode == 0xD5)
            {
                data.Text = "push de";
            }
            else if (data.OpCode == 0xE5)
            {
                data.Text = "push hl";
            }


            else if (data.OpCode == 0xc8)
            {
                data.Text = "retz";
            }
            else if (data.OpCode == 0xc9)
            {
                data.Text = "ret";
            }

            //2 byte no immediate instructions
            else if (data.OpCode == 0xdd09)
            {
                data.Text = "add ix,bc";
            }
            else if (data.OpCode == 0xdd19)
            {
                data.Text = "add ix,de";
            }
            else if (data.OpCode == 0xfd09)
            {
                data.Text = "add iy,bc";
            }
            else if (data.OpCode == 0xfd19)
            {
                data.Text = "add iy,de";
            }

            else if (data.OpCode == 0xdd2B)
            {
                data.Text = "dec ix";
            }
            else if (data.OpCode == 0xfd2B)
            {
                data.Text = "dec iy";
            }

            else if (data.OpCode == 0xf3)
            {
                data.Text = "di";
            }
            else if (data.OpCode == 0xfB)
            {
                data.Text = "ei";
            }

            else if (data.OpCode == 0xdd2B)
            {
                data.Text = "inc ix";
            }
            else if (data.OpCode == 0xdd2B)
            {
                data.Text = "inc iy";
            }

            else if (data.OpCode == 0xed80)
            {
                data.Text = "neg";
            }
            else if (data.OpCode == 0xed80)
            {
                data.Text = "ldir";
            }

            else if (data.OpCode == 0xdde1)
            {
                data.Text = "pop ix";
            }
            else if (data.OpCode == 0xfde1)
            {
                data.Text = "pop iy";
            }

            else if (data.OpCode == 0xdde5)
            {
                data.Text = "push ix";
            }
            else if (data.OpCode == 0xfde5)
            {
                data.Text = "push iy";
            }

            else if (data.OpCode == 0xcb21)
            {
                data.Text = "sla c";
            }
            else if (data.OpCode == 0xcb2f)
            {
                data.Text = "sra";
            }
            else if (data.OpCode == 0xcb3f)
            {
                data.Text = "srl";
            }

            else if (data.OpCode == 0xEDB8)
            {
                data.Text = "cls";
            }
            else if (data.OpCode == 0xed79)
            {
                data.Text = "outlin";
            }
            else if (data.OpCode == 0xed41)
            {
                data.Text = "setp";
            }
            else if (data.OpCode == 0xedb3)
            {
                data.Text = "newln";
            }
            else if (data.OpCode == 0xed59)
            {
                data.Text = "quit";
            }
            else if (data.OpCode == 0xed61)
            {
                data.Text = "save";
            }
            else if (data.OpCode == 0xed69)
            {
                data.Text = "restore";
            }
            else if (data.OpCode == 0xed51)
            {
                data.Text = "readkb";
            }
            else if (data.OpCode == 0xEDAB)
            {
                data.Text = "stsln";
            }


            // r,n instructions
            else if (data.OpCode == 0xc6)
            {
                data.Text = String.Format("add {0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0xe6)
            {
                data.Text = String.Format("and {0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0xfe)
            {
                data.Text = String.Format("cp {0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x3e)
            {
                data.Text = String.Format("ld {0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x06)
            {
                data.Text = String.Format("ld b,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x0e)
            {
                data.Text = String.Format("ld c,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x16)
            {
                data.Text = String.Format("ld d,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x1e)
            {
                data.Text = String.Format("ld e,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x26)
            {
                data.Text = String.Format("ld h,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x2E)
            {
                data.Text = String.Format("ld l,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0xf6)
            {
                data.Text = String.Format("or {0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0xd6)
            {
                data.Text = String.Format("sub {0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0xee)
            {
                data.Text = String.Format("xor {0:X2}", data.ImmediateByte1);
            }

            //relative jumps
            else if (data.OpCode == 0x18)
            {
                data.Text = String.Format("jr {0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x38)
            {
                data.Text = String.Format("jr c,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x30)
            {
                data.Text = String.Format("jr nc,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x28)
            {
                data.Text = String.Format("jr z,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x20)
            {
                data.Text = String.Format("jr nz,{0:X2}", data.ImmediateByte1);
            }
            else if (data.OpCode == 0x10)
            {
                data.Text = String.Format("djnz {0:X2}", data.ImmediateByte1);
            }


            //call instructions
            else if (data.OpCode == 0xC4)
            {
                data.Text = "call nz," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xCC)
            {
                data.Text = "call z," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xCD)
            {
                data.Text = "call " + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xC3)
            {
                data.Text = "jp " + GetAddr(data.ImmediateWord, labels);
            }
            //dajpc,fajpm,d2jpnc,c2jpnz,f2jpp,cajz
            else if (data.OpCode == 0xDA)
            {
                data.Text = "jp c," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xFA)
            {
                data.Text = "jp m," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xD2)
            {
                data.Text = "jp nc," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xC2)
            {
                data.Text = "jp nz," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xF2)
            {
                data.Text = "jp p," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xCA)
            {
                data.Text = "jp z, " + GetAddr(data.ImmediateWord, labels);
            }
            //rel jumps
            else if (data.OpCode == 0x38)
            {
                data.Text = "jr c, " + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0x30)
            {
                data.Text = "jr nc, " + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0x20)
            {
                data.Text = "jr nz, " + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0x28)
            {
                data.Text = "jr z, " + GetAddr(data.ImmediateWord, labels);
            }


            //op nn instructions (ld bc,0000h)
            else if (data.OpCode == 0x32)
            {
                data.Text = "ld (" + GetAddr(data.ImmediateWord, labels) + "),a";
            }
            else if (data.OpCode == 0xed43)
            {
                data.Text = "ld (" + GetAddr(data.ImmediateWord, labels) + "),bc";
            }
            else if (data.OpCode == 0xed53)
            {
                data.Text = "ld (" + GetAddr(data.ImmediateWord, labels) + "),de";
            }
            else if (data.OpCode == 0x22)
            {
                data.Text = "ld (" + GetAddr(data.ImmediateWord, labels) + "),hl";
            }
            else if (data.OpCode == 0xdd22)
            {
                data.Text = "ld (" + GetAddr(data.ImmediateWord, labels) + "),ix";
            }
            else if (data.OpCode == 0xfd22)
            {
                data.Text = "ld (" + GetAddr(data.ImmediateWord, labels) + "),iy";
            }
            else if (data.OpCode == 0xed73)
            {
                data.Text = "ld (" + GetAddr(data.ImmediateWord, labels) + "),sp";
            }
            else if (data.OpCode == 0x3a)
            {
                data.Text = "ld a,(" + GetAddr(data.ImmediateWord, labels) + ")";
            }
            else if (data.OpCode == 0xed4b)
            {
                data.Text = "ld bc,(" + GetAddr(data.ImmediateWord, labels) + ")";
            }
            else if (data.OpCode == 0x01)
            {
                data.Text = "ld bc," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xed5b)
            {
                data.Text = "ld de,(" + GetAddr(data.ImmediateWord, labels) + ")";
            }
            else if (data.OpCode == 0x11)
            {
                data.Text = "ld de," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0x2a)
            {
                data.Text = "ld hl,(" + GetAddr(data.ImmediateWord, labels) + ")";
            }
            else if (data.OpCode == 0x21)
            {
                data.Text = "ld hl," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xdd2a)
            {
                data.Text = "ld ix,(" + GetAddr(data.ImmediateWord, labels) + ")";
            }
            else if (data.OpCode == 0xdd21)
            {
                data.Text = "ld ix," + GetAddr(data.ImmediateWord, labels);
            }
            else if (data.OpCode == 0xfd2a)
            {
                data.Text = "ld iy,(" + GetAddr(data.ImmediateWord, labels) + ")";
            }
            else if (data.OpCode == 0xfd21)
            {
                data.Text = "ld iy," + GetAddr(data.ImmediateWord, labels);
            }

            else if (data.OpCode == 0xed7b)
            {
                data.Text = "ld sp,(" + GetAddr(data.ImmediateWord, labels) + ")";
            }
            else if (data.OpCode == 0x31)
            {
                data.Text = "ld sp," + GetAddr(data.ImmediateWord, labels);
            }

            //2 byte opcode, 1 byte immediate
            //ld r, (ix+d)
            else if (data.OpCode == 0xDD7E && (data.ImmediateByte1 & 0x46) == 0x46)
            {//ld r, (ix+d)
                string r = GetRegister((byte)(data.OpCode % 256));

                data.Text = string.Format(
                    "ld {0},(ix+{1})",
                    r,
                    data.ImmediateByte1
                    );
            }
            //ld r, (iy+d)
            else if (data.OpCode == 0xFFDE && (data.ImmediateByte1 & 0x46) == 0x46)
            {
                string r = GetRegister((byte)(data.OpCode % 256));

                data.Text = string.Format(
                    "ld {0},(iy+{1})",
                    r,
                    data.ImmediateByte1
                    );
            }
            //two immediate bytes ( res, bit, set, ld (ix+n),n )
            else if (data.OpCode == 0xDDCB) //res 0,(ix+n) or bit 0,(ix+n), or set 0,(ix+n)
            {
                int    hi2 = GetHi2(data.ImmediateByte2);
                int    bit = GetBit(data.ImmediateByte1);
                string op  = "";
                if (hi2 == 1)
                {
                    op = "bit";
                }
                else if (hi2 == 2)
                {
                    op = "res";
                }
                else if (hi2 == 3)
                {
                    op = "set";
                }

                data.Text = String.Format("{0} {1},(ix+{2})",
                                          op,
                                          bit,
                                          data.ImmediateByte1
                                          );
            }
            else if (data.OpCode == 0xFDCB)
            {
                int    hi2 = GetHi2(data.ImmediateByte2);
                int    bit = GetBit(data.ImmediateByte1);
                string op  = "";
                if (hi2 == 1)
                {
                    op = "bit";
                }
                else if (hi2 == 2)
                {
                    op = "res";
                }
                else if (hi2 == 3)
                {
                    op = "set";
                }

                data.Text = String.Format("{0} {1},(iy+{2})",
                                          op,
                                          bit,
                                          data.ImmediateByte1
                                          );
            }
            else if (data.OpCode == 0xdd36)
            {//ld (ix+d),n
                data.Text = String.Format("ld (ix+{0}),{1}",
                                          data.ImmediateByte1,
                                          data.ImmediateByte2
                                          );
            }
            else if (data.OpCode == 0xdd36)
            {//ld (ix+d),n
                data.Text = String.Format("ld (ix+{0}),{1}",
                                          data.ImmediateByte1,
                                          data.ImmediateByte2
                                          );
            }
            else if (data.OpCode == 0xfd36)
            {//ld (iy+d),n
                data.Text = String.Format("ld (iy+{0}),{1}",
                                          data.ImmediateByte1,
                                          data.ImmediateByte2
                                          );
            }
            else
            {
                data.Text = "0x??";
                return(false);
            }

            return(true);
            //immediates, not same size ld ?
        }