// Compare
private int CMP(IByteOperandStrategy operand)
{
var cmp16 = Accumulator - operand.Read(this);
Flags = Flags
.Set(FlagIndex.Carry, ((cmp16 & 0x00FF) >= Accumulator && operand.Read(this) != 0))
.Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_subAC(Accumulator, operand.Read(this)))
.calc_SZP((byte)cmp16);
return(operand == OpMem ? 7 : 4);
}
// INR Increment Register or Memory
// If register C contains 99H, the instruction: INR C will cause register C to contain 9AH
private int INR(IByteOperandStrategy op)
{
var in8 = op.Read(this);
var out8 = (byte)(in8 + 1);
Flags = Flags
.Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_AC(in8, 1))
.calc_SZP(out8);
op.Write(this, out8);
return(op == OpMem ? 10 : 5);
}
// ADD Register or Memory To Accumulator
private int ADD(IByteOperandStrategy operand)
{
var in8 = operand.Read(this);
var out16 = Accumulator + in8;
Flags = Flags
.Set(FlagIndex.Carry, ((out16 & 0xFF00) != 0)).Set(FlagIndex.AuxCarry, AuxCarryPredicates.calc_AC(Accumulator, in8))
.calc_SZP((byte)out16);
Accumulator = (byte)out16;
return(operand == OpMem ? 7 : 4);
}
// OR
private int ORA(IByteOperandStrategy operand)
{
var out8 = (byte)(Accumulator | operand.Read(this));
Accumulator = out8;
Flags = Flags
.calc_SZP(out8)
.Set(FlagIndex.Carry, false)
.Set(FlagIndex.AuxCarry, false);
return(4);
}
// ANA Logical and Register or Memory With Accumulator
private int ANA(IByteOperandStrategy operand)
{
var inAcc8 = Accumulator;
var in8 = operand.Read(this);
var out8 = (byte)(inAcc8 & in8);
Accumulator = out8;
Flags = Flags
.calc_SZP(out8)
.Set(FlagIndex.Carry, false)
.Set(FlagIndex.AuxCarry, (((inAcc8 | in8) >> 3) & 1) == 1);
return(4);
}
//SBB Subtract Register or Memory From Accumulator With Borrow
private int SBB(IByteOperandStrategy operand)
{
var in8 = operand.Read(this);
var out16 = Accumulator - in8 - (Flags.IsSet(FlagIndex.Carry) ? 1 : 0);
var acPred = Flags.IsSet(FlagIndex.Carry) ? AuxCarryPredicates.calc_subAC_borrow : AuxCarryPredicates.calc_subAC;
Flags = Flags
.Set(FlagIndex.AuxCarry, acPred(Accumulator, in8))
.Set(FlagIndex.Carry, ((out16 & 0x00FF) >= Accumulator && in8 != 0 | Flags.IsSet(FlagIndex.Carry)))
.calc_SZP((byte)out16);
Accumulator = (byte)out16;
return(operand == OpMem ? 7 : 4);
}
// MOV Move register to register
private int MOV(IByteOperandStrategy rDest, IByteOperandStrategy rSrc)
{
rDest.Write(this, rSrc.Read(this));
return(5);
}