public void Dispatch(Cpu8086 cpu, OpCodeManager.Instruction instruction)
{
var address = InstructionHelper.GetInstructionRealAddress(cpu, instruction.SegmentPrefix, instruction.Argument2, instruction.Argument2Value, instruction.Argument2Displacement);
var memory = cpu.ReadU16(address);
var segment = cpu.ReadU16(address + 2);
cpu.SetRegister(_register, segment);
switch ((Register)instruction.Argument1)
{
case Register.AX:
case Register.CX:
case Register.DX:
case Register.BX:
case Register.SP:
case Register.BP:
case Register.SI:
case Register.DI:
case Register.IP:
case Register.CS:
case Register.DS:
case Register.ES:
case Register.SS:
cpu.SetRegister((Register)instruction.Argument1, memory);
break;
default:
throw new NotImplementedException();
}
}
public void Dispatch(Cpu8086 cpu, OpCodeManager.Instruction instruction)
{
var prefix = instruction.SegmentPrefix;
if (prefix == Register.Invalid)
{
prefix = Register.DS;
}
var sourceAddress = InstructionHelper.SegmentToAddress(cpu.GetRegister(prefix), cpu.GetRegister(Register.SI));
byte size;
if (instruction.Flag.Has(OpCodeManager.OpCodeFlag.Size8))
{
cpu.SetRegisterU8(Register.AL, cpu.ReadU8(sourceAddress));
size = 1;
}
else
{
cpu.SetRegister(Register.AX, cpu.ReadU16(sourceAddress));
size = 2;
}
if (!cpu.GetFlags().Has(FlagsRegister.Direction))
{
cpu.SetRegister(Register.SI, (ushort)(cpu.GetRegister(Register.SI) + size));
}
else
{
cpu.SetRegister(Register.SI, (ushort)(cpu.GetRegister(Register.SI) - size));
}
}
public void Dispatch(Cpu8086 cpu, OpCodeManager.Instruction instruction)
{
ushort value1;
ushort value2;
byte size;
if (instruction.Flag.Has(OpCodeManager.OpCodeFlag.Size8))
{
value1 = cpu.GetRegisterU8(Register.AL);
value2 = cpu.ReadU8(InstructionHelper.SegmentToAddress(cpu.GetRegister(Register.ES), cpu.GetRegister(Register.DI)));
size = 1;
}
else
{
value1 = cpu.GetRegister(Register.AX);
value2 = cpu.ReadU16(InstructionHelper.SegmentToAddress(cpu.GetRegister(Register.ES), cpu.GetRegister(Register.DI)));
size = 2;
}
var result = value1 - value2;
InstructionHelper.CalculateSubFlags(cpu, instruction.Flag, value1, value2, result);
if (!cpu.GetFlags().Has(FlagsRegister.Direction))
{
cpu.IncRegister(Register.DI, size);
}
else
{
cpu.DecRegister(Register.DI, size);
}
}
public void Dispatch(Cpu8086 cpu, OpCodeManager.Instruction instruction)
{
switch (instruction.Argument1)
{
case (int)Register.SP:
// 8086 has a bug where it pushes SP after it has been modified
// cpu.registers[(int)Register.SP] -= 2;
// cpu.WriteU16(SegmentToAddress(cpu.GetRegister(Register.SS), cpu.GetRegister(Register.SP)), cpu.GetRegister(Register.SP));
// break;
case (int)Register.AX:
case (int)Register.CX:
case (int)Register.DX:
case (int)Register.BX:
case (int)Register.BP:
case (int)Register.SI:
case (int)Register.DI:
case (int)Register.IP:
case (int)Register.CS:
case (int)Register.DS:
case (int)Register.ES:
case (int)Register.SS:
case unchecked ((int)Register.FLAGS):
cpu.Push(cpu.GetRegister((Register)instruction.Argument1));
break;
case OpCodeManager.ARG_DEREFERENCE:
case OpCodeManager.ARG_MEMORY:
var address = InstructionHelper.GetInstructionRealAddress(cpu, instruction.SegmentPrefix, instruction.Argument1, instruction.Argument1Value, instruction.Argument1Displacement);
cpu.Push(cpu.ReadU16(address));
break;
default:
throw new ArgumentOutOfRangeException();
}
}
public void Dispatch(Cpu8086 cpu, OpCodeManager.Instruction instruction)
{
switch (instruction.Argument1)
{
case OpCodeManager.ARG_FAR_MEMORY:
cpu.SetRegister(Register.CS, (ushort)((uint)instruction.Argument1Value >> 16));
cpu.SetRegister(Register.IP, (ushort)(instruction.Argument1Value & 0xFFFF));
break;
case OpCodeManager.ARG_DEREFERENCE:
case OpCodeManager.ARG_MEMORY:
var address = InstructionHelper.GetInstructionRealAddress(cpu, instruction.SegmentPrefix, instruction.Argument1, instruction.Argument1Value, instruction.Argument1Displacement);
cpu.SetRegister(Register.CS, cpu.ReadU16(address + 2));
cpu.SetRegister(Register.IP, cpu.ReadU16(address));
break;
default:
throw new InvalidOperationException();
}
}
public void Dispatch(Cpu8086 cpu, OpCodeManager.Instruction instruction)
{
var segment = Register.DS;
if (instruction.SegmentPrefix != Register.Invalid)
{
segment = instruction.SegmentPrefix;
}
ushort value1;
ushort value2;
byte size;
if (instruction.Flag.Has(OpCodeManager.OpCodeFlag.Size8))
{
value1 = cpu.ReadU8(InstructionHelper.SegmentToAddress(cpu.GetRegister(segment), cpu.GetRegister(Register.SI)));
value2 = cpu.ReadU8(InstructionHelper.SegmentToAddress(cpu.GetRegister(Register.ES), cpu.GetRegister(Register.DI)));
size = 1;
}
else
{
value1 = cpu.ReadU16(InstructionHelper.SegmentToAddress(cpu.GetRegister(segment), cpu.GetRegister(Register.SI)));
value2 = cpu.ReadU16(InstructionHelper.SegmentToAddress(cpu.GetRegister(Register.ES), cpu.GetRegister(Register.DI)));
size = 2;
}
var result = value1 - value2;
InstructionHelper.CalculateSubFlags(cpu, instruction.Flag, value1, value2, result);
if (!cpu.GetFlags().Has(FlagsRegister.Direction))
{
cpu.SetRegister(Register.DI, (ushort)(cpu.GetRegister(Register.DI) + size));
cpu.SetRegister(Register.SI, (ushort)(cpu.GetRegister(Register.SI) + size));
}
else
{
cpu.SetRegister(Register.DI, (ushort)(cpu.GetRegister(Register.DI) - size));
cpu.SetRegister(Register.SI, (ushort)(cpu.GetRegister(Register.SI) - size));
}
}
private ushort ProcessExchangeSecond(Cpu8086 cpu, OpCodeManager.Instruction instruction, ushort value)
{
ushort tmp;
switch (instruction.Argument2)
{
case (int)Register.AX:
case (int)Register.CX:
case (int)Register.DX:
case (int)Register.BX:
case (int)Register.SP:
case (int)Register.BP:
case (int)Register.SI:
case (int)Register.DI:
case (int)Register.IP:
case (int)Register.CS:
case (int)Register.DS:
case (int)Register.ES:
case (int)Register.SS:
tmp = cpu.GetRegister((Register)instruction.Argument2);
cpu.SetRegister((Register)instruction.Argument2, (byte)value);
break;
case OpCodeManager.ARG_BYTE_REGISTER:
tmp = cpu.GetRegisterU8((Register)instruction.Argument2Value);
cpu.SetRegisterU8((Register)instruction.Argument2Value, (byte)value);
break;
case OpCodeManager.ARG_DEREFERENCE:
case OpCodeManager.ARG_MEMORY:
var address = InstructionHelper.GetInstructionRealAddress(cpu, instruction.SegmentPrefix, instruction.Argument2, instruction.Argument2Value, instruction.Argument2Displacement);
tmp = cpu.ReadU16(address);
cpu.WriteU16(address, value);
break;
default:
throw new NotImplementedException();
}
return(tmp);
}
public void Dispatch(Cpu8086 cpu, OpCodeManager.Instruction instruction)
{
var segment = Register.DS;
if (instruction.SegmentPrefix != Register.Invalid)
{
segment = instruction.SegmentPrefix;
}
var sourceAddress = InstructionHelper.SegmentToAddress(cpu.GetRegister(segment), cpu.GetRegister(Register.SI));
var destAddress = InstructionHelper.SegmentToAddress(cpu.GetRegister(Register.ES), cpu.GetRegister(Register.DI));
byte size;
if (instruction.Flag.Has(OpCodeManager.OpCodeFlag.Size8))
{
var value = cpu.ReadU8(sourceAddress);
cpu.WriteU8(destAddress, value);
size = 1;
}
else
{
var value = cpu.ReadU16(sourceAddress);
cpu.WriteU16(destAddress, value);
size = 2;
}
if (!cpu.GetFlags().Has(FlagsRegister.Direction))
{
cpu.IncRegister(Register.DI, size);
cpu.IncRegister(Register.SI, size);
}
else
{
cpu.DecRegister(Register.DI, size);
cpu.DecRegister(Register.SI, size);
}
}