public OpCodeTable()
{
// initialize the entire table with new records
for (ushort ii = 0; ii < _opCodeTable.Length; ii++)
{
_opCodeTable[ii] = new OpCodeRecord(OpCodeNotImplemented);
}
}
public OpCodeTable()
{
// initialize the entire table with new records
for (ushort ii = 0; ii < _opCodeTable.Length; ii++)
{
_opCodeTable[ii] = new OpCodeRecord(OpCodeNotImplemented);
}
}
private void InitOpCodeTable()
{
_opTable[0x00] = new OpCodeRecord(ExecuteADD_General);
_opTable[0x01] = new OpCodeRecord(ExecuteADD_General);
_opTable[0x02] = new OpCodeRecord(ExecuteADD_General);
_opTable[0x03] = new OpCodeRecord(ExecuteADD_General);
_opTable[0x04] = new OpCodeRecord(ExecuteADD_Immediate);
_opTable[0x05] = new OpCodeRecord(ExecuteADD_Immediate);
_opTable[0x06] = new OpCodeRecord(Execute_PUSH);
_opTable[0x07] = new OpCodeRecord(Execute_POP);
_opTable[0x08] = new OpCodeRecord(ExecuteLogical_General); // OR
_opTable[0x09] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x0a] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x0b] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x0c] = new OpCodeRecord(ExecuteLogical_Immediate);
_opTable[0x0d] = new OpCodeRecord(ExecuteLogical_Immediate);
_opTable[0x0e] = new OpCodeRecord(Execute_PUSH);
// POP CS is not a valid instruction
_opTable[0x0f] = new OpCodeRecord(() => { });
_opTable[0x10] = new OpCodeRecord(ExecuteADD_General);
_opTable[0x11] = new OpCodeRecord(ExecuteADD_General);
_opTable[0x12] = new OpCodeRecord(ExecuteADD_General);
_opTable[0x13] = new OpCodeRecord(ExecuteADD_General);
_opTable[0x14] = new OpCodeRecord(ExecuteADD_Immediate);
_opTable[0x15] = new OpCodeRecord(ExecuteADD_Immediate);
_opTable[0x16] = new OpCodeRecord(Execute_PUSH);
_opTable[0x17] = new OpCodeRecord(Execute_POP);
_opTable[0x18] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x19] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x1a] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x1b] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x1c] = new OpCodeRecord(ExecuteSUB_Immediate);
_opTable[0x1d] = new OpCodeRecord(ExecuteSUB_Immediate);
_opTable[0x1e] = new OpCodeRecord(Execute_PUSH);
_opTable[0x1f] = new OpCodeRecord(Execute_POP);
_opTable[0x20] = new OpCodeRecord(ExecuteLogical_General); // AND
_opTable[0x21] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x22] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x23] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x24] = new OpCodeRecord(ExecuteLogical_Immediate);
_opTable[0x25] = new OpCodeRecord(ExecuteLogical_Immediate);
//_opTable[0x26] segment override is processed in the NextInstruction() method
_opTable[0x27] = new OpCodeRecord(Execute_DecimalAdjustADD);
_opTable[0x28] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x29] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x2a] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x2b] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x2c] = new OpCodeRecord(ExecuteSUB_Immediate);
_opTable[0x2d] = new OpCodeRecord(ExecuteSUB_Immediate);
//_opTable[0x2e] segment override is processed in the NextInstruction() method
_opTable[0x2f] = new OpCodeRecord(Execute_DecimalAdjustSUB);
_opTable[0x30] = new OpCodeRecord(ExecuteLogical_General); // XOR
_opTable[0x31] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x32] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x33] = new OpCodeRecord(ExecuteLogical_General);
_opTable[0x34] = new OpCodeRecord(ExecuteLogical_Immediate);
_opTable[0x35] = new OpCodeRecord(ExecuteLogical_Immediate);
//_opTable[0x36] segment override is processed in the NextInstruction() method
_opTable[0x37] = new OpCodeRecord(Execute_AsciiAdjustADD);
_opTable[0x38] = new OpCodeRecord(ExecuteSUB_General); // CMP
_opTable[0x39] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x3a] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x3b] = new OpCodeRecord(ExecuteSUB_General);
_opTable[0x3c] = new OpCodeRecord(ExecuteSUB_Immediate);
_opTable[0x3d] = new OpCodeRecord(ExecuteSUB_Immediate);
//_opTable[0x3e] segment override is processed in the NextInstruction() method
_opTable[0x3f] = new OpCodeRecord(Execute_AsciiAdjustSUB);
_opTable[0x40] = new OpCodeRecord(ExecuteINC);
_opTable[0x41] = new OpCodeRecord(ExecuteINC);
_opTable[0x42] = new OpCodeRecord(ExecuteINC);
_opTable[0x43] = new OpCodeRecord(ExecuteINC);
_opTable[0x44] = new OpCodeRecord(ExecuteINC);
_opTable[0x45] = new OpCodeRecord(ExecuteINC);
_opTable[0x46] = new OpCodeRecord(ExecuteINC);
_opTable[0x47] = new OpCodeRecord(ExecuteINC);
_opTable[0x48] = new OpCodeRecord(ExecuteDEC);
_opTable[0x49] = new OpCodeRecord(ExecuteDEC);
_opTable[0x4a] = new OpCodeRecord(ExecuteDEC);
_opTable[0x4b] = new OpCodeRecord(ExecuteDEC);
_opTable[0x4c] = new OpCodeRecord(ExecuteDEC);
_opTable[0x4d] = new OpCodeRecord(ExecuteDEC);
_opTable[0x4e] = new OpCodeRecord(ExecuteDEC);
_opTable[0x4f] = new OpCodeRecord(ExecuteDEC);
_opTable[0x50] = new OpCodeRecord(Execute_PUSH);
_opTable[0x51] = new OpCodeRecord(Execute_PUSH);
_opTable[0x52] = new OpCodeRecord(Execute_PUSH);
_opTable[0x53] = new OpCodeRecord(Execute_PUSH);
_opTable[0x54] = new OpCodeRecord(Execute_PUSH);
_opTable[0x55] = new OpCodeRecord(Execute_PUSH);
_opTable[0x56] = new OpCodeRecord(Execute_PUSH);
_opTable[0x57] = new OpCodeRecord(Execute_PUSH);
_opTable[0x58] = new OpCodeRecord(Execute_POP);
_opTable[0x59] = new OpCodeRecord(Execute_POP);
_opTable[0x5a] = new OpCodeRecord(Execute_POP);
_opTable[0x5b] = new OpCodeRecord(Execute_POP);
_opTable[0x5c] = new OpCodeRecord(Execute_POP);
_opTable[0x5d] = new OpCodeRecord(Execute_POP);
_opTable[0x5e] = new OpCodeRecord(Execute_POP);
_opTable[0x5f] = new OpCodeRecord(Execute_POP);
_opTable[0x60] = new OpCodeRecord(Execute_PUSHA);
_opTable[0x61] = new OpCodeRecord(Execute_POPA);
_opTable[0x62] = new OpCodeRecord(Execute_Bound);
_opTable[0x63] = new OpCodeRecord(() => { throw new InvalidOperationException("Instruction 0x63 is not implemented"); });
_opTable[0x64] = new OpCodeRecord(() => { throw new InvalidOperationException("Instruction 0x64 is not implemented"); });
_opTable[0x65] = new OpCodeRecord(() => { throw new InvalidOperationException("Instruction 0x65 is not implemented"); });
_opTable[0x66] = new OpCodeRecord(() => { throw new InvalidOperationException("Instruction 0x66 is not implemented"); });
_opTable[0x67] = new OpCodeRecord(() => { throw new InvalidOperationException("Instruction 0x67 is not implemented"); });
_opTable[0x68] = new OpCodeRecord(() => // PUSH imm-16
{
Push(GetImmediate16());
});
_opTable[0x69] = new OpCodeRecord(() => // IMUL REG-16, RM-16, Imm
{
byte mod = 0, reg = 0, rm = 0;
SplitAddrByte(_bus.NextIP(), ref mod, ref reg, ref rm);
int word_size = GetWordSize();
int direction = GetDirection();
ushort oper1 = (ushort)GetSourceData(direction, word_size, mod, reg, rm);
ushort oper2 = GetImmediate16();
uint oper1ext = SignExtend32(oper1);
uint oper2ext = SignExtend32(oper2);
uint result = oper1ext * oper2ext;
SaveToDestination((ushort)(result & 0xffff), direction, word_size, mod, reg, rm);
if( (result & 0xffff0000) != 0 )
{
_creg.CarryFlag = true;
_creg.OverflowFlag = true;
}
else
{
_creg.CarryFlag = false;
_creg.OverflowFlag = false;
}
});
_opTable[0x6a] = new OpCodeRecord(() => // PUSH imm-8
{
Push(_bus.NextIP());
});
_opTable[0x6b] = new OpCodeRecord(() =>
{
byte mod = 0, reg = 0, rm = 0;
SplitAddrByte(_bus.NextIP(), ref mod, ref reg, ref rm);
int word_size = GetWordSize();
int direction = GetDirection();
ushort oper1 = (ushort)GetSourceData(direction, word_size, mod, reg, rm);
ushort oper2 = _bus.NextIP();
uint oper1ext = SignExtend32(oper1);
uint oper2ext = SignExtend32(oper2);
uint result = oper1ext * oper2ext;
SaveToDestination((ushort)(result & 0xffff), direction, word_size, mod, reg, rm);
if ((result & 0xffff0000) != 0)
{
_creg.CarryFlag = true;
_creg.OverflowFlag = true;
}
else
{
_creg.CarryFlag = false;
_creg.OverflowFlag = false;
}
});
_opTable[0x6c] = new OpCodeRecord(() => // INSB
{
// if repetition is on but CX is 0 then do nothing
if( ( _repeat ) && ( _reg.CX == 0 ) )
{
}
else
{
do
{
Execute_IN_String();
if (_creg.DirectionFlag)
_reg.DI--;
else
_reg.DI++;
if (_repeat)
_reg.CX--;
} while (_reg.CX != 0);
_repeat = false;
}
});
_opTable[0x6d] = new OpCodeRecord(() => // INSW
{
// if repetition is on but CX is 0 then do nothing
if ((_repeat) && (_reg.CX == 0))
{
}
else
{
do
{
Execute_IN_String();
if (_creg.DirectionFlag)
_reg.DI -= 2;
else
_reg.DI += 2;
if (_repeat)
_reg.CX--;
} while (_reg.CX != 0);
_repeat = false;
}
});
_opTable[0x6e] = new OpCodeRecord(() => // OUTSB
{
// if repetition is on but CX is 0 then do nothing
if ((_repeat) && (_reg.CX == 0))
{
}
else
{
do
{
Execute_OUT_String();
if (_creg.DirectionFlag)
_reg.SI -= 1;
else
_reg.SI += 1;
if (_repeat)
_reg.CX--;
} while (_reg.CX != 0);
_repeat = false;
}
});
_opTable[0x6f] = new OpCodeRecord(() => // OUTSW
{
// if repetition is on but CX is 0 then do nothing
if ((_repeat) && (_reg.CX == 0))
{
}
else
{
do
{
Execute_OUT_String();
if (_creg.DirectionFlag)
_reg.SI -= 2;
else
_reg.SI += 2;
if (_repeat)
_reg.CX--;
} while (_reg.CX != 0);
_repeat = false;
}
});
_opTable[0x70] = new OpCodeRecord(Execute_CondJump);
_opTable[0x71] = new OpCodeRecord(Execute_CondJump);
_opTable[0x72] = new OpCodeRecord(Execute_CondJump);
_opTable[0x73] = new OpCodeRecord(Execute_CondJump);
_opTable[0x74] = new OpCodeRecord(Execute_CondJump);
_opTable[0x75] = new OpCodeRecord(Execute_CondJump);
_opTable[0x76] = new OpCodeRecord(Execute_CondJump);
_opTable[0x77] = new OpCodeRecord(Execute_CondJump);
_opTable[0x78] = new OpCodeRecord(Execute_CondJump);
_opTable[0x79] = new OpCodeRecord(Execute_CondJump);
_opTable[0x7a] = new OpCodeRecord(Execute_CondJump);
_opTable[0x7b] = new OpCodeRecord(Execute_CondJump);
_opTable[0x7c] = new OpCodeRecord(Execute_CondJump);
_opTable[0x7d] = new OpCodeRecord(Execute_CondJump);
_opTable[0x7e] = new OpCodeRecord(Execute_CondJump);
_opTable[0x7f] = new OpCodeRecord(Execute_CondJump);
_opTable[0x80] = new OpCodeRecord(Execute_Group1);
_opTable[0x81] = new OpCodeRecord(Execute_Group1);
_opTable[0x82] = new OpCodeRecord(Execute_Group1);
_opTable[0x83] = new OpCodeRecord(Execute_Group1);
_opTable[0x84] = new OpCodeRecord(ExecuteLogical_General); // TEST
_opTable[0x85] = new OpCodeRecord(ExecuteLogical_General); // TEST
_opTable[0x86] = new OpCodeRecord(ExecuteXCHG_General);
_opTable[0x87] = new OpCodeRecord(ExecuteXCHG_General);
_opTable[0x88] = new OpCodeRecord(ExecuteMOV_General);
_opTable[0x89] = new OpCodeRecord(ExecuteMOV_General);
_opTable[0x8a] = new OpCodeRecord(ExecuteMOV_General);
_opTable[0x8b] = new OpCodeRecord(ExecuteMOV_General);
_opTable[0x8c] = new OpCodeRecord(ExecuteMOV_SReg);
_opTable[0x8d] = new OpCodeRecord(Execute_LEA);
_opTable[0x8e] = new OpCodeRecord(ExecuteMOV_SReg); // MOV CS - this should never be used in practice
_opTable[0x8f] = new OpCodeRecord(Execute_POP);
_opTable[0x90] = new OpCodeRecord(ExecuteXCHG_AX);
_opTable[0x91] = new OpCodeRecord(ExecuteXCHG_AX);
_opTable[0x92] = new OpCodeRecord(ExecuteXCHG_AX);
_opTable[0x93] = new OpCodeRecord(ExecuteXCHG_AX);
_opTable[0x94] = new OpCodeRecord(ExecuteXCHG_AX);
_opTable[0x95] = new OpCodeRecord(ExecuteXCHG_AX);
_opTable[0x96] = new OpCodeRecord(ExecuteXCHG_AX);
_opTable[0x97] = new OpCodeRecord(ExecuteXCHG_AX);
_opTable[0x98] = new OpCodeRecord(Execute_CBW);
_opTable[0x99] = new OpCodeRecord(Execute_CWD);
_opTable[0x9a] = new OpCodeRecord(Execute_CallFar);
_opTable[0x9b] = new OpCodeRecord(() => { }); // WAIT (for now NOP)
_opTable[0x9c] = new OpCodeRecord(Execute_PUSH);
_opTable[0x9d] = new OpCodeRecord(Execute_POP);
// SAHF - Store SH to flags
_opTable[0x9e] = new OpCodeRecord(() => { _creg.Register = new DataRegister16((byte)(_creg.Register >> 8), _reg.AH); });
// LAHF - Load AH from flags
_opTable[0x9f] = new OpCodeRecord( () => { _reg.AH = (byte)(_creg.Register & 0x00ff); });
_opTable[0xa0] = new OpCodeRecord(ExecuteMOV_Mem);
_opTable[0xa1] = new OpCodeRecord(ExecuteMOV_Mem);
_opTable[0xa2] = new OpCodeRecord(ExecuteMOV_Mem);
_opTable[0xa3] = new OpCodeRecord(ExecuteMOV_Mem);
_opTable[0xa4] = new OpCodeRecord(Execute_MoveString);
_opTable[0xa5] = new OpCodeRecord(Execute_MoveString);
_opTable[0xa6] = new OpCodeRecord(Execute_CompareString);
_opTable[0xa7] = new OpCodeRecord(Execute_CompareString);
_opTable[0xa8] = new OpCodeRecord(ExecuteLogical_Immediate);
_opTable[0xa9] = new OpCodeRecord(ExecuteLogical_Immediate);
_opTable[0xaa] = new OpCodeRecord(Execute_StoreString);
_opTable[0xab] = new OpCodeRecord(Execute_StoreString);
_opTable[0xac] = new OpCodeRecord(Execute_LoadString);
_opTable[0xad] = new OpCodeRecord(Execute_LoadString);
_opTable[0xae] = new OpCodeRecord(Execute_ScanString);
_opTable[0xaf] = new OpCodeRecord(Execute_ScanString);
_opTable[0xb0] = new OpCodeRecord(ExecuteMOV_Imm8);
_opTable[0xb1] = new OpCodeRecord(ExecuteMOV_Imm8);
_opTable[0xb2] = new OpCodeRecord(ExecuteMOV_Imm8);
_opTable[0xb3] = new OpCodeRecord(ExecuteMOV_Imm8);
_opTable[0xb4] = new OpCodeRecord(ExecuteMOV_Imm8);
_opTable[0xb5] = new OpCodeRecord(ExecuteMOV_Imm8);
_opTable[0xb6] = new OpCodeRecord(ExecuteMOV_Imm8);
_opTable[0xb7] = new OpCodeRecord(ExecuteMOV_Imm8);
_opTable[0xb8] = new OpCodeRecord(ExecuteMOV_Imm16);
_opTable[0xb9] = new OpCodeRecord(ExecuteMOV_Imm16);
_opTable[0xba] = new OpCodeRecord(ExecuteMOV_Imm16);
_opTable[0xbb] = new OpCodeRecord(ExecuteMOV_Imm16);
_opTable[0xbc] = new OpCodeRecord(ExecuteMOV_Imm16);
_opTable[0xbd] = new OpCodeRecord(ExecuteMOV_Imm16);
_opTable[0xbe] = new OpCodeRecord(ExecuteMOV_Imm16);
_opTable[0xbf] = new OpCodeRecord(ExecuteMOV_Imm16);
// GRP2 rm-8 imm-8 (80186)
_opTable[0xc0] = new OpCodeRecord(Execute_RotateAndShift);
// GRP2 rm-16 imm-16 (80186)
_opTable[0xc1] = new OpCodeRecord(Execute_RotateAndShift);
_opTable[0xc2] = new OpCodeRecord(() => // ret imm-16
{
ushort oper = GetImmediate16();
_bus.IP = Pop();
_reg.SP += oper;
});
_opTable[0xc3] = new OpCodeRecord(() => // ret
{
_bus.IP = Pop();
});
_opTable[0xc4] = new OpCodeRecord(Execute_LDS_LES);
_opTable[0xc5] = new OpCodeRecord(Execute_LDS_LES);
_opTable[0xc6] = new OpCodeRecord(ExecuteMOV_c6);
_opTable[0xc7] = new OpCodeRecord(ExecuteMOV_c7);
_opTable[0xc8] = new OpCodeRecord(() => { throw new InvalidOperationException("Instruction 0xc8 is not implemented"); });
_opTable[0xc9] = new OpCodeRecord(() => { throw new InvalidOperationException("Instruction 0xc9 is not implemented"); });
_opTable[0xca] = new OpCodeRecord(() => // retf imm-16
{
ushort oper = GetImmediate16();
_bus.IP = Pop();
_bus.CS = Pop();
_reg.SP += oper;
});
_opTable[0xcb] = new OpCodeRecord(() => // retf
{
_bus.IP = Pop();
_bus.CS = Pop();
});
_opTable[0xcc] = new OpCodeRecord(() => { Interrupt(3); });
_opTable[0xcd] = new OpCodeRecord(() => { Interrupt(_bus.NextIP()); });
_opTable[0xce] = new OpCodeRecord(() => { if (_creg.OverflowFlag) Interrupt(4); });
_opTable[0xcf] = new OpCodeRecord(() => // iret
{
_bus.IP = Pop();
_bus.CS = Pop();
_creg.Register = Pop();
});
_opTable[0xd0] = new OpCodeRecord(Execute_RotateAndShift);
_opTable[0xd1] = new OpCodeRecord(Execute_RotateAndShift);
_opTable[0xd2] = new OpCodeRecord(Execute_RotateAndShift);
_opTable[0xd3] = new OpCodeRecord(Execute_RotateAndShift);
_opTable[0xd4] = new OpCodeRecord(Execute_AsciiAdjustMUL);
_opTable[0xd5] = new OpCodeRecord(Execute_AsciiAdjustDIV);
// undocumented SALC instruction
_opTable[0xd6] = new OpCodeRecord(() => { if (_creg.CarryFlag) _reg.AL = 0xff; else _reg.AL = 0x00; });
_opTable[0xd7] = new OpCodeRecord(Execute_XLAT);
// D8-DF ESC OPCODE,SOURCE (to math co-processor)
// these are unsupported but they use the address byte so this should read
_opTable[0xd8] = new OpCodeRecord(() => { _bus.NextIP(); } );
_opTable[0xd9] = new OpCodeRecord(() => { _bus.NextIP(); });
_opTable[0xda] = new OpCodeRecord(() => { _bus.NextIP(); });
_opTable[0xdb] = new OpCodeRecord(() => { _bus.NextIP(); });
_opTable[0xdc] = new OpCodeRecord(() => { _bus.NextIP(); });
_opTable[0xdd] = new OpCodeRecord(() => { _bus.NextIP(); });
_opTable[0xde] = new OpCodeRecord(() => { _bus.NextIP(); });
_opTable[0xdf] = new OpCodeRecord(() => { _bus.NextIP(); });
_opTable[0xe0] = new OpCodeRecord(Execute_Loop);
_opTable[0xe1] = new OpCodeRecord(Execute_Loop);
_opTable[0xe2] = new OpCodeRecord(Execute_Loop);
_opTable[0xe3] = new OpCodeRecord(Execute_JumpCXZ);
_opTable[0xe4] = new OpCodeRecord(Execute_IN);
_opTable[0xe5] = new OpCodeRecord(Execute_IN);
_opTable[0xe6] = new OpCodeRecord(Execute_OUT);
_opTable[0xe7] = new OpCodeRecord(Execute_OUT);
_opTable[0xe8] = new OpCodeRecord(Execute_CallNear);
_opTable[0xe9] = new OpCodeRecord(Execute_JumpNear);
_opTable[0xea] = new OpCodeRecord(Execute_JumpFar);
_opTable[0xeb] = new OpCodeRecord(Execute_JumpShort);
_opTable[0xec] = new OpCodeRecord(Execute_IN);
_opTable[0xed] = new OpCodeRecord(Execute_IN);
_opTable[0xee] = new OpCodeRecord(Execute_OUT);
_opTable[0xef] = new OpCodeRecord(Execute_OUT);
_opTable[0xf0] = new OpCodeRecord(() => { }); // LOCK
_opTable[0xf1] = new OpCodeRecord(() => { }); // officially undocumented opcode
// F2 REPNE/REPNZ
_opTable[0xf2] = new OpCodeRecord(() =>
{
_repeat = true;
_repeatType = 1;
});
// F3 REP/E/Z
_opTable[0xf3] = new OpCodeRecord(() =>
{
_repeat = true;
_repeatType = 2;
});
_opTable[0xf4] = new OpCodeRecord(() => // F4 HLT
{
_bus.IP--;
Halted = true;
});
_opTable[0xf5] = new OpCodeRecord(() => { _creg.CarryFlag = !_creg.CarryFlag; }); // CMC - complement carry flag
_opTable[0xf6] = new OpCodeRecord(Execute_Group3);
_opTable[0xf7] = new OpCodeRecord(Execute_Group3);
_opTable[0xf8] = new OpCodeRecord(() => { _creg.CarryFlag = false; }); // F8 CLC - clear carry flag
_opTable[0xf9] = new OpCodeRecord(() => { _creg.CarryFlag = true; }); // F9 STC - set carry flag
_opTable[0xfa] = new OpCodeRecord(() => { _creg.InterruptEnable = false; }); // FA CLI - clear interrupt flag
_opTable[0xfb] = new OpCodeRecord(() => { _creg.InterruptEnable = true; }); // FB STI - set interrupt flag
_opTable[0xfc] = new OpCodeRecord(() => { _creg.DirectionFlag = false; }); // FC CLD - clear direction flag
_opTable[0xfd] = new OpCodeRecord(() => { _creg.DirectionFlag = true; }); // FD STD - set direction flag
_opTable[0xfe] = new OpCodeRecord(Execute_Group4);
_opTable[0xff] = new OpCodeRecord(Execute_Group5);
}