public int Execute()
{
int SaveC;
int Operand = 0, Temp = 0;
int FetchCode;
int NOPS, TempPC;
if (Breakpoint.Contains(PC) || debug)
{
// Do something for a hardware breaskpoint
// Log stuff
//if (!((PC >= 0xFE3A) && (PC <= 0xFE4F))) // Ignore OUTCH
//{
// System.Diagnostics.Debug.WriteLine(string.Format("PC:{0,4:X} A:{1,2:X} B:{2,2:X} IX:{3,4:X} SP:{4,4:X}", PC, A, B, IX, SP));
//}
}
if (!((PC >= 0xFE3A) && (PC <= 0xFE4F))) // Ignore OUTCH
{
System.Diagnostics.Debug.WriteLine(string.Format("PC:{0,4:X} A:{1,2:X} B:{2,2:X} IX:{3,4:X} SP:{4,4:X} CC:{5,6}", PC, A, B, IX, SP, Convert.ToString(Flags.H * 32 + Flags.I * 16 + Flags.N * 8 + Flags.Z * 4 + Flags.V * 2 + Flags.C, 2)));
}
FetchCode = ReadMem(PC);
Clock = Clock + Cycles[FetchCode];
switch (AddrMode[FetchCode])
{
case IMMEDIATE:
Operand = ReadMem(PC + 1);
break;
case DIRECT:
Operand = ReadMem(ReadMem(PC + 1));
break;
case INDEXED:
Operand = ReadMem(IX + ReadMem(PC + 1));
break;
case EXTENDED:
Operand = ReadMem((ReadMem(PC + 1) << 8) + ReadMem(PC + 2));
break;
case INHERENT:
//
break;
case RELATIVE:
Operand = ReadMem(PC + 1);
if (Operand > 0x80)
{
Operand = (0 - Operand) & 0xFF;
Operand = -Operand;
}
break;
}
;
switch (FetchCode)
{
//============ LOGIC OPCODES ==========
//ADDA
case 0x8B:
case 0x9B:
case 0xAB:
case 0xBB:
Temp = A;
Temp += Operand;
TestH(A, Operand, Temp);
TestC(A, Operand, Temp);
TestV(A, Operand, Temp);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
break;
//ADDB
case 0xCB:
case 0xDB:
case 0xEB:
case 0xFB:
Temp = B;
Temp += Operand;
TestH(B, Operand, Temp);
TestC(B, Operand, Temp);
TestV(B, Operand, Temp);
B = Temp & 0xFF;
TestN(B);
TestZ(B);
break;
//ABA
case 0x1B:
Temp = A;
Temp += B;
TestH(A, B, Temp);
TestC(A, B, Temp);
TestV(A, B, Temp);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
break;
//ADCA
case 0x89:
case 0x99:
case 0xA9:
case 0xB9:
Temp = A;
Temp += Operand + Flags.C;
TestH(A, Operand, Temp);
TestC(A, Operand, Temp);
TestV(A, Operand, Temp);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
break;
//ADCB
case 0xC9:
case 0xD9:
case 0xE9:
case 0xF9:
Temp = B;
Temp += Operand + Flags.C;
TestH(B, Operand, Temp);
TestC(B, Operand, Temp);
TestV(B, Operand, Temp);
B = Temp & 0xFF;
TestN(B);
TestZ(B);
break;
//ANDA
case 0x84:
case 0x94:
case 0xA4:
case 0xB4:
A &= Operand;
TestN(A);
TestZ(A);
Flags.V = 0;
break;
//ANDB
case 0xC4:
case 0xD4:
case 0xE4:
case 0xF4:
B &= Operand;
TestN(B);
TestZ(B);
Flags.V = 0;
break;
//BITA
case 0x85:
case 0x95:
case 0xA5:
case 0xB5:
Temp = A & Operand;
TestN(Temp);
TestZ(Temp);
Flags.V = 0;
break;
//BITB
case 0xC5:
case 0xD5:
case 0xE5:
case 0xF5:
Temp = B & Operand;
TestN(Temp);
TestZ(Temp);
Flags.V = 0;
break;
//CLR
case 0x6F:
WriteMem(IX + ReadMem(PC + 1), 0);
Flags.N = 0;
Flags.Z = 1;
Flags.V = 0;
Flags.C = 0;
break;
case 0x7F:
WriteMem((ReadMem(PC + 1) << 8) + ReadMem(PC + 2), 0);
Flags.N = 0;
Flags.Z = 1;
Flags.V = 0;
Flags.C = 0;
break;
//CLRA
case 0x4F:
A = 0;
Flags.N = 0;
Flags.Z = 1;
Flags.V = 0;
Flags.C = 0;
break;
//CLRB
case 0x5F:
B = 0;
Flags.N = 0;
Flags.Z = 1;
Flags.V = 0;
Flags.C = 0;
break;
//CMPA
case 0x81:
case 0x91:
case 0xA1:
case 0xB1:
Temp = A - Operand;
if (Temp < 0)
{
Flags.C = 1;
}
else
{
Flags.C = 0;
}
TestV(A, Operand, Temp);
TestN(Temp);
TestZ(Temp);
break;
//CMPB
case 0xC1:
case 0xD1:
case 0xE1:
case 0xF1:
Temp = B - Operand;
if (Temp < 0)
{
Flags.C = 1;
}
else
{
Flags.C = 0;
}
TestV(B, Operand, Temp);
TestN(Temp);
TestZ(Temp);
break;
//CBA
case 0x11:
Temp = A;
Temp -= B;
if (Temp < 0)
{
Flags.C = 1;
}
else
{
Flags.C = 0;
}
TestV(A, B, Temp);
TestN(Temp);
TestZ(Temp);
break;
//COM
case 0x63:
TempPC = IX + ReadMem(PC + 1);
Temp = ~ReadMem(TempPC) & 0xFF;
WriteMem(TempPC, Temp);
TestN(Temp);
TestZ(Temp);
Flags.V = 0;
Flags.C = 1;
break;
case 0x73:
TempPC = ReadMem(PC + 1);
TempPC = (TempPC << 8) + ReadMem(PC + 2);
Temp = ~ReadMem(TempPC) & 0xFF;
WriteMem(TempPC, Temp);
TestN(Temp);
TestZ(Temp);
Flags.V = 0;
Flags.C = 1;
break;
//COMA
case 0x43:
A = ~A & 0xFF;
TestN(A);
TestZ(A);
Flags.V = 0;
Flags.C = 1;
break;
//COMB
case 0x53:
B = ~B & 0xFF;
TestN(B);
TestZ(B);
Flags.V = 0;
Flags.C = 1;
break;
//NEG
case 0x60:
TempPC = IX + ReadMem(PC + 1);
Temp = (0 - ReadMem(TempPC)) & 0xFF;
WriteMem(TempPC, Temp);
TestN(Temp);
Bit7V(Temp);
TestZC(Temp);
break;
case 0x70:
TempPC = ReadMem(PC + 1);
TempPC = (TempPC << 8) + ReadMem(PC + 2);
Temp = (0 - ReadMem(TempPC)) & 0xFF;
WriteMem(TempPC, Temp);
TestN(Temp);
Bit7V(Temp);
TestZC(Temp);
break;
//NEGA
case 0x40:
Temp = A;
Temp = 0 - Temp;
A = Temp & 0xFF;
TestN(A);
Bit7V(A);
TestZC(A);
break;
//NEGB
case 0x50:
Temp = B;
Temp = 0 - Temp;
B = Temp & 0xFF;
TestN(B);
Bit7V(B);
TestZC(B);
break;
//DAA
case 0x19:
Temp = A;
if (((A & 0xF) > 9) | (Flags.H == 1))
{
A += 0x06;
TestV(Temp, 0x06, A);
}
if ((((A & 0xF0) >> 8) > 9) | (Flags.C == 1))
{
A += 0x60;
TestV(Temp, 0x60, A);
}
if (((A & 0xF) > 9) & ((A & 0xF0) == 0x90))
{
A += 0x60;
TestV(Temp, 0x60, A);
}
if (((A & 0xF0) >> 8) > 9)
{
Flags.C = 1;
}
TestN(A);
TestZ(A);
break;
//DEC
case 0x6A:
TempPC = IX + ReadMem(PC + 1);
Temp = ReadMem(TempPC);
Bit7V(Temp);
WriteMem(TempPC, (Temp - 1) & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
break;
case 0x7A:
TempPC = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
Bit7V(Temp);
WriteMem(TempPC, (Temp - 1) & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
break;
//DECA
case 0x4A:
Temp = A;
Bit7V(Temp);
Temp = Temp - 1;
A = Temp & 0xFF;
TestN(A);
TestZ(A);
break;
//DECB
case 0x5A:
Temp = B;
Bit7V(Temp);
Temp = Temp - 1;
B = Temp & 0xFF;
TestN(B);
TestZ(B);
break;
//EORA
case 0x88:
case 0x98:
case 0xA8:
case 0xB8:
A ^= Operand;
TestN(A);
TestZ(A);
Flags.V = 0;
break;
//EORB
case 0xC8:
case 0xD8:
case 0xE8:
case 0xF8:
B ^= Operand;
TestN(B);
TestZ(B);
Flags.V = 0;
break;
//INC
case 0x6C:
TempPC = IX + ReadMem(PC + 1);
Temp = ReadMem(TempPC);
if (Temp == 0x7F)
{
Flags.V = 1;
}
else
{
Flags.V = 0;
}
Temp = Temp + 1;
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
break;
case 0x7C:
TempPC = ReadMem(PC + 1);
TempPC = TempPC * 0x100 + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
if (Temp == 0x7F)
{
Flags.V = 1;
}
else
{
Flags.V = 0;
}
Temp++;
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
break;
//INCA
case 0x4C:
Temp = A;
if (Temp == 0x7F)
{
Flags.V = 1;
}
else
{
Flags.V = 0;
}
Temp++;
A = Temp & 0xFF;
TestN(A);
TestZ(A);
break;
//INCB
case 0x5C:
Temp = B;
if (Temp == 0x7F)
{
Flags.V = 1;
}
else
{
Flags.V = 0;
}
Temp++;
B = Temp & 0xFF;
TestN(B);
TestZ(B);
break;
//LDAA
case 0x86:
case 0x96:
case 0xA6:
case 0xB6:
A = Operand;
TestN(A);
TestZ(A);
Flags.V = 0;
break;
//LDAB
case 0xC6:
case 0xD6:
case 0xE6:
case 0xF6:
B = Operand;
TestN(B);
TestZ(B);
Flags.V = 0;
break;
//ORA
case 0x8A:
case 0x9A:
case 0xAA:
case 0xBA:
A |= Operand;
TestN(A);
TestZ(A);
Flags.V = 0;
break;
//ORB
case 0xCA:
case 0xDA:
case 0xEA:
case 0xFA:
B |= Operand;
TestN(B);
TestZ(B);
Flags.V = 0;
break;
//PSHA
case 0x36:
WriteMem(SP--, A);
break;
//PSHB
case 0x37:
WriteMem(SP--, B);
break;
//PULA
case 0x32:
A = ReadMem(++SP);
break;
//PULB
case 0x33:
B = ReadMem(++SP);
break;
//ROL
case 0x69:
TempPC = IX + ReadMem(PC + 1);
Temp = ReadMem(TempPC);
SaveC = Flags.C;
Bit7C(Temp);
Temp = (Temp << 1) + SaveC;
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
case 0x79:
TempPC = ReadMem(PC + 1);
TempPC = (TempPC << 8) + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
SaveC = Flags.C;
Bit7C(Temp);
Temp = (Temp << 1) + SaveC;
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
//ROLA
case 0x49:
Temp = A;
SaveC = Flags.C;
Bit7C(A);
Temp = (Temp << 1) + SaveC;
A = Temp & 0xFF;
TestN(A);
TestZ(A);
Flags.V = Flags.N ^ Flags.C;
break;
//ROLB
case 0x59:
Temp = B;
SaveC = Flags.C;
Bit7C(B);
Temp = (Temp << 1) + SaveC;
B = Temp & 0xFF;
TestN(B);
TestZ(B);
Flags.V = Flags.N ^ Flags.C;
break;
//ROR
case 0x66:
TempPC = IX + ReadMem(PC + 1);
Temp = ReadMem(TempPC);
SaveC = Flags.C;
Flags.C = Temp & 1;
Temp = (Temp >> 1) + (SaveC << 7);
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
case 0x76:
TempPC = ReadMem(PC + 1);
TempPC = (Temp << 8) + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
SaveC = Flags.C;
Flags.C = Temp & 1;
Temp = (Temp >> 1) + (SaveC << 7);
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
//RORA
case 0x46:
Temp = A;
SaveC = Flags.C;
Flags.C = Temp & 1;
Temp = (Temp >> 1) + (SaveC << 7);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
Flags.V = Flags.N ^ Flags.C;
break;
//RORB
case 0x56:
Temp = B;
SaveC = Flags.C;
Flags.C = Temp & 1;
Temp = (Temp >> 1) + (SaveC << 7);
B = Temp & 0xFF;
TestN(B);
TestZ(B);
Flags.V = Flags.N ^ Flags.C;
break;
//ASL
case 0x68:
TempPC = IX + ReadMem(PC + 1);
Temp = ReadMem(TempPC);
Flags.C = (Temp >> 7) & 1;
Temp = (Temp << 1);
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
case 0x78:
TempPC = ReadMem(PC + 1);
TempPC = TempPC * 0x100 + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
Flags.C = (Temp >> 7) & 1;
Temp = (Temp << 1);
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
//ASLA
case 0x48:
Temp = A;
Flags.C = (Temp >> 7) & 1;
Temp = (Temp << 1);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
Flags.V = Flags.N ^ Flags.C;
break;
//ASLB
case 0x58:
Temp = B;
Flags.C = (Temp >> 7) & 1;
Temp = (Temp << 1);
B = Temp & 0xFF;
TestN(B);
TestZ(B);
Flags.V = Flags.N ^ Flags.C;
break;
//ASR
case 0x67:
TempPC = IX + ReadMem(PC + 1);
Temp = ReadMem(TempPC);
Flags.C = Temp & 1;
Temp = (Temp >> 1) + (Temp & 0x80);
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
case 0x77:
TempPC = ReadMem(PC + 1);
TempPC = TempPC * 0x100 + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
Flags.C = Temp & 1;
Temp = (Temp >> 1) + (Temp & 0x80);
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
//ASRA
case 0x47:
Temp = A;
Flags.C = Temp & 1;
Temp = (Temp >> 1) + (Temp & 0x80);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
Flags.V = Flags.N ^ Flags.C;
break;
//ASRB
case 0x57:
Temp = B;
Flags.C = Temp & 1;
Temp = (Temp >> 1) + (Temp & 0x80);
B = Temp & 0xFF;
TestN(B);
TestZ(B);
Flags.V = Flags.N ^ Flags.C;
break;
//LSR
case 0x64:
TempPC = IX + ReadMem(PC + 1);
Temp = ReadMem(TempPC);
Flags.C = Temp & 1;
Temp = Temp >> 1;
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
case 0x74:
TempPC = ReadMem(PC + 1);
TempPC = (TempPC << 8) + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
Flags.C = Temp & 1;
Temp = Temp >> 1;
WriteMem(TempPC, Temp & 0xFF);
TestN(ReadMem(TempPC));
TestZ(ReadMem(TempPC));
Flags.V = Flags.N ^ Flags.C;
break;
//LSRA
case 0x44:
Temp = A;
Flags.C = Temp & 1;
Temp = Temp >> 1;
A = Temp & 0xFF;
TestN(A);
TestZ(A);
Flags.V = Flags.N ^ Flags.C;
break;
//LSRB
case 0x54:
Temp = B;
Flags.C = Temp & 1;
Temp = Temp >> 1;
B = Temp & 0xFF;
TestN(B);
TestZ(B);
Flags.V = Flags.N ^ Flags.C;
break;
//STAA
case 0x97:
WriteMem(Memory[PC + 1], A);
TestN(A);
TestZ(A);
Flags.V = 0;
break;
case 0xA7:
TempPC = IX + ReadMem(PC + 1);
WriteMem(TempPC, A);
TestN(A);
TestZ(A);
Flags.V = 0;
//if(((TempPC <= 0xC16F) && (TempPC >= 0xC110)) && ((TempPC & 0xF)== 0)) Render(TempPC / 0x10 & 0xF, A);
//if((TempPC <= 0xC16F) && (TempPC >= 0xC110)) Render(TempPC / 0x10 & 0xF, A);
break;
case 0xB7:
TempPC = ReadMem(PC + 1);
TempPC = (TempPC << 8) + ReadMem(PC + 2);
WriteMem(TempPC, A);
TestN(A);
TestZ(A);
Flags.V = 0;
//if((TempPC <= 0xC16F) && (TempPC >= 0xC110)) Render(TempPC / 0x10 & 0xF, A);
break;
//STAB
case 0xD7:
WriteMem(ReadMem(PC + 1), B);
TestN(B);
TestZ(B);
Flags.V = 0;
break;
case 0xE7:
TempPC = IX + ReadMem(PC + 1);
WriteMem(TempPC, B);
TestN(B);
TestZ(B);
Flags.V = 0;
//if((TempPC <= 0xC16F) && (TempPC >= 0xC110)) Render(TempPC / 0x10 & 0xF, B);
break;
case 0xF7:
TempPC = ReadMem(PC + 1);
TempPC = (TempPC << 8) + ReadMem(PC + 2);
WriteMem(TempPC, B);
TestN(B);
TestZ(B);
Flags.V = 0;
// if((TempPC <= 0xC16F) && (TempPC >= 0xC110)) Render(TempPC / 0x10 & 0xF, B);
break;
//SUBA
case 0x80:
case 0x90:
case 0xA0:
case 0xB0:
Temp = A;
Temp -= Operand;
if (Operand > A)
{
Flags.C = 1;
}
else
{
Flags.C = 0;
}
//TestC(A, Operand);
TestV(A, Operand, Temp);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
break;
//SUBB
case 0xC0:
case 0xD0:
case 0xE0:
case 0xF0:
Temp = B;
Temp = Temp - Operand;
if (Operand > B)
{
Flags.C = 1;
}
else
{
Flags.C = 0;
}
// TestC(B, Operand);
TestV(B, Operand, Temp);
B = Temp & 0xFF;
TestN(B);
TestZ(B);
break;
//SBA
case 0x10:
Temp = A;
Temp = Temp - B;
TestC(A, B, Temp);
TestV(A, B, Temp);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
break;
//SBCA
case 0x82:
case 0x92:
case 0xA2:
case 0xB2:
Temp = A;
Temp -= Operand;
Temp -= Flags.C;
if (Operand > A)
{
Flags.C = 1;
}
else
{
Flags.C = 0;
}
//TestC(A, Operand);
TestV(A, Operand, Temp);
A = Temp & 0xFF;
TestN(A);
TestZ(A);
break;
//SBCB
case 0xC2:
case 0xD2:
case 0xE2:
case 0xF2:
Temp = B;
Temp = Temp - Operand;
Temp -= Flags.C;
if (Operand > B)
{
Flags.C = 1;
}
else
{
Flags.C = 0;
}
// TestC(B, Operand);
TestV(B, Operand, Temp);
B = Temp & 0xFF;
TestN(B);
TestZ(B);
break;
//TAB
case 0x16:
B = A;
TestN(B);
TestZ(B);
Flags.V = 0;
break;
//TBA
case 0x17:
A = B;
TestN(A);
TestZ(A);
Flags.V = 0;
break;
//TST
case 0x6D:
Temp = ReadMem(IX + ReadMem(PC + 1));
TestN(Temp);
TestZ(Temp);
Flags.V = 0;
Flags.C = 0;
break;
case 0x7D:
TempPC = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
TestN(Temp);
TestZ(Temp);
Flags.V = 0;
Flags.C = 0;
break;
//TSTA
case 0x4D:
TestN(A);
TestZ(A);
Flags.V = 0;
Flags.C = 0;
break;
//TSTB
case 0x5D:
TestN(B);
TestZ(B);
Flags.V = 0;
Flags.C = 0;
break;
//============ INDEX REGISTER AND STACK OPCODES ==========
//CPX
case 0x8C:
Temp = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
Operand = Temp;
Temp = IX - Temp;
TestV(IX, Operand, Temp);
TestN(Temp >> 8);
TestZ(Temp);
break;
case 0x9C:
Temp = (ReadMem(PC + 1) << 8) + ReadMem(ReadMem(PC + 1) + 1);
Operand = Temp;
Temp = IX - Temp;
TestV(IX, Operand, Temp);
TestN(Temp >> 8);
TestZ(Temp);
break;
case 0xAC:
Temp = (ReadMem(IX + ReadMem(PC + 1)) << 8) + ReadMem(IX + ReadMem(PC + 1) + 1);
Operand = Temp;
Temp = IX - Temp;
TestV(IX, Operand, Temp);
TestN(Temp >> 8);
TestZ(Temp);
break;
case 0xBC:
TempPC = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
Temp = ReadMem(TempPC);
Temp = (Temp << 8) + ReadMem(TempPC + 1);
Operand = Temp;
Temp = IX - Temp;
TestV(IX, Operand, Temp);
TestN(Temp >> 8);
TestZ(Temp);
break;
//DEX
case 0x09:
IX--;
TestZ(IX);
break;
//DES
case 0x34:
SP--;
break;
//INX
case 0x8:
IX++;
TestZ(IX);
break;
//INS
case 0x31:
SP++;
break;
//LDX
case 0xCE:
//FOROPT
IX = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
TestN(IX >> 8);
TestZ(IX);
Flags.V = 0;
break;
case 0xDE:
//FOROPT
IX = (ReadMem(ReadMem(PC + 1)) << 8) + ReadMem(ReadMem(PC + 1) + 1);
TestN(IX >> 8);
TestZ(IX);
Flags.V = 0;
break;
case 0xEE:
TempPC = IX + ReadMem(PC + 1);
IX = (ReadMem(TempPC) << 8) + ReadMem(TempPC + 1);
TestN(IX >> 8);
TestZ(IX);
Flags.V = 0;
break;
case 0xFE:
TempPC = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
IX = (ReadMem(TempPC) << 8) + ReadMem(TempPC + 1);
TestN(IX >> 8);
TestZ(IX);
Flags.V = 0;
//LDS
break;
case 0x8E:
SP = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
TestN(SP >> 8);
TestZ(SP);
Flags.V = 0;
break;
case 0x9E:
TempPC = ReadMem(PC + 1);
SP = (ReadMem(TempPC) << 8) + ReadMem(TempPC + 1);
TestN(SP >> 8);
TestZ(SP);
Flags.V = 0;
break;
case 0xAE:
TempPC = IX + ReadMem(PC + 1);
SP = ReadMem(TempPC);
SP = (SP << 8) + ReadMem(TempPC + 1);
TestN(SP >> 8);
TestZ(SP);
Flags.V = 0;
break;
case 0xBE:
TempPC = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
SP = (ReadMem(TempPC) << 8) + ReadMem(TempPC + 1);
TestN(SP >> 8);
TestZ(SP);
Flags.V = 0;
break;
//STX
case 0xDF:
TempPC = ReadMem(PC + 1);
WriteMem(TempPC, (IX >> 8) & 0xFF);
WriteMem(TempPC + 1, IX & 0xFF);
TestN(IX >> 8);
TestZ(IX);
Flags.V = 0;
break;
case 0xEF:
TempPC = IX + ReadMem(PC + 1);
WriteMem(TempPC, (IX >> 8) & 0xFF);
WriteMem(TempPC + 1, IX & 0xFF);
TestN(IX >> 8);
TestZ(IX);
Flags.V = 0;
break;
case 0xFF:
TempPC = ReadMem(PC + 1);
TempPC = (TempPC << 8) + ReadMem(PC + 2);
WriteMem(TempPC, (IX >> 8) & 0xFF);
WriteMem(TempPC + 1, IX & 0xFF);
TestN(IX >> 8);
TestZ(IX);
Flags.V = 0;
break;
//STS
case 0x9F:
TempPC = ReadMem(PC + 1);
WriteMem(TempPC, (SP / 0x100) & 0xFF);
WriteMem(TempPC + 1, SP & 0xFF);
TestN(SP >> 8);
TestZ(SP);
Flags.V = 0;
break;
case 0xAF:
TempPC = IX + ReadMem(PC + 1);
WriteMem(TempPC, (SP >> 8) & 0xFF);
WriteMem(TempPC + 1, SP & 0xFF);
TestN(SP >> 8);
TestZ(SP);
Flags.V = 0;
break;
case 0xBF:
TempPC = ReadMem(PC + 1);
TempPC = (TempPC << 8) + ReadMem(PC + 2);
WriteMem(TempPC, (SP >> 8) & 0xFF);
WriteMem(TempPC + 1, SP & 0xFF);
TestN(SP >> 8);
TestZ(SP);
Flags.V = 0;
break;
//TXS
case 0x35:
SP = IX - 1;
break;
//TSX
case 0x30:
IX = SP + 1;
break;
//============ JUMP AND BRANCH OPCODES ==========
//BRA
case 0x20:
PC += Operand;
break;
//BCC
case 0x24:
if (Flags.C == 0)
{
PC += Operand;
}
break;
//BCS
case 0x25:
if (Flags.C == 1)
{
PC += Operand;
}
break;
//BEQ
case 0x27:
if (Flags.Z == 1)
{
PC += Operand;
}
break;
//BGE
case 0x2C:
if ((Flags.N ^ Flags.V) == 0)
{
PC += Operand;
}
break;
//BGT
case 0x2E:
if ((Flags.Z | (Flags.N ^ Flags.V)) == 0)
{
PC += Operand;
}
break;
//BHI
case 0x22:
if ((Flags.C | Flags.Z) == 0)
{
PC += Operand;
}
break;
//BLE
case 0x2F:
if ((Flags.Z | (Flags.N ^ Flags.V)) == 1)
{
PC += Operand;
}
break;
//BLS
case 0x23:
if ((Flags.C | Flags.Z) == 1)
{
PC += Operand;
}
break;
//BLT
case 0x2D:
if ((Flags.N ^ Flags.V) == 1)
{
PC += Operand;
}
break;
//BMI
case 0x2B:
if (Flags.N == 1)
{
PC += Operand;
}
break;
//BNE
case 0x26:
if (Flags.Z == 0)
{
PC += Operand;
}
break;
//BVC
case 0x28:
if (Flags.V == 0)
{
PC += Operand;
}
break;
//BVS
case 0x29:
if (Flags.V == 1)
{
PC += Operand;
}
break;
//BPL
case 0x2A:
if (Flags.N == 0)
{
PC += Operand;
}
break;
//BSR
case 0x8D:
PC += 2;
WriteMem(SP--, PC & 0xFF);
WriteMem(SP--, (PC >> 8) & 0xFF);
PC += Operand;
break;
//JMP
case 0x6E:
PC = IX + ReadMem(PC + 1);
break;
case 0x7E:
PC = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
break;
//JSR
case 0xAD:
TempPC = PC;
PC += 3;
WriteMem(SP--, PC & 0xFF);
WriteMem(SP--, (PC >> 8) & 0xFF);
PC = IX + ReadMem(TempPC + 1);
break;
case 0xBD:
TempPC = (ReadMem(PC + 1) << 8) + ReadMem(PC + 2);
PC += 3;
WriteMem(SP--, PC & 0xFF);
WriteMem(SP--, (PC >> 8) & 0xFF);
PC = TempPC;
break;
//NOP
case 0x1:
PC = PC + 1;
break;
//RTI
case 0x3B:
SP++;
Flags.H = (ReadMem(SP) >> 6) & 1;
Flags.I = (ReadMem(SP) >> 5) & 1;
Flags.N = (ReadMem(SP) >> 4) & 1;
Flags.Z = (ReadMem(SP) >> 3) & 1;
Flags.V = (ReadMem(SP) >> 2) & 1;
Flags.C = (ReadMem(SP) >> 1) & 1;
SP++;
B = ReadMem(SP);
SP++;
A = ReadMem(SP);
SP += 2;
IX = (ReadMem(SP - 1) << 8) + ReadMem(SP);
SP += 2;
PC = (ReadMem(SP - 1) << 8) + ReadMem(SP);
break;
//RTS
case 0x39:
SP += 2;
PC = (ReadMem(SP - 1) << 8) + ReadMem(SP);
break;
//SWI
case 0x3F:
//erp!
WriteMem(SP--, PC & 0xFF);
WriteMem(SP--, (PC >> 8) & 0xFF);
WriteMem(SP--, IX & 0xFF);
WriteMem(SP--, (IX >> 8) & 0xFF);
WriteMem(SP--, A);
WriteMem(SP--, B);
WriteMem(SP--, Flags.H * 32 + Flags.I * 16 + Flags.N * 8 + Flags.Z * 4 + Flags.V * 2 + Flags.C);
Flags.I = 1;
//SP = SP - 7;
PC = (ReadMem(0xFFFA) << 8) + ReadMem(0xFFFB);
break;
//WAI
case 0x3E:
//if Flags.I = 1;
// Paused = False
//Else
// Paused = True
//End if
break;
//============ CONDITIONS CODE REGISTER OPCODES ==========
//CLC
case 0xC:
Flags.C = 0;
break;
//CLI
case 0xE:
Flags.I = 0;
break;
//CLV
case 0xA:
Flags.V = 0;
break;
//SEC
case 0xD:
Flags.C = 1;
break;
//SEI
case 0xF:
Flags.I = 1;
break;
//SEV
case 0xB:
Flags.Z = 1;
break;
//TAP
case 0x6:
Flags.H = A / 32 & 1;
Flags.I = A / 16 & 1;
Flags.N = A / 8 & 1;
Flags.Z = A / 4 & 1;
Flags.V = A / 2 & 1;
Flags.C = A & 1;
break;
//TPA
case 0x7:
A += Flags.H * 32;
A += Flags.I * 16;
A += Flags.N * 8;
A += Flags.Z * 4;
A += Flags.V * 2;
A += Flags.C;
break;
//INVALID
default:
break;
}
NOPS = CalcNOPs(FetchCode);
switch (FetchCode)
{
case 0x8D:
case 0x6E:
case 0x7E:
case 0xAD:
case 0xBD:
case 0x39:
case 0x3F:
case 0x3B:
// PC already calculated
break;
default:
PC += NOPS;
break;
}
//Safety check
lastpc = PC;
//Interrupt handlers
if ((NMI == 0) || ((IRQ == 0) && (Flags.I == 0)))
{
WriteMem(SP, PC & 0xFF);
WriteMem(SP - 1, PC / 0x100 & 0xFF);
WriteMem(SP - 2, IX & 0xFF);
WriteMem(SP - 3, IX / 0x100 & 0xFF);
WriteMem(SP - 4, A);
WriteMem(SP - 5, B);
WriteMem(SP - 6, Flags.H * 32 + Flags.I * 16 + Flags.N * 8 + Flags.Z * 4 + Flags.V * 2 + Flags.C);
SP = SP - 7;
Flags.I = 1;
PC = (ReadMem(0xFFFC) << 8) + ReadMem(0xFFFD);
}
return(Cycles[FetchCode]);
}