/// <summary>
/// Returns VAT and VATless fees
/// </summary>
/// <returns></returns>
public string ToString(ShowFormat fmt)
{
if (fmt == ShowFormat.withoutVAT)
{
return(String.Format(new NumberFormatInfo(), $"{VATLess,10:C2}"));
}
else if (fmt == ShowFormat.withVAT)
{
return(String.Format(new NumberFormatInfo(), $"{WithVAT,10:C2}"));
}
return(String.Format(new NumberFormatInfo(), $"{VATLess,10:C2} / {WithVAT,10:C2}"));
}
/// <summary>
/// Main execution
/// </summary>
public string Disassemble(ref ushort OpCodeAddress)
{
ushort Address;
ushort IOAddress;
byte opcode;
ShowFormat DataFormat = ShowFormat.Decimal;
// Fetch next instruction
opcode = _Memory.ReadByte(OpCodeAddress++);
if (opcode == 0x76) // HALT
{
// The first check is for HALT otherwise it could be
// interpreted as LD (HL),(HL)
return("HALT");
}
else if ((opcode & 0xC0) == 0x40) // LD r,r
{
string reg1 = GetHalfRegister((byte)(opcode >> 3));
string reg2 = GetHalfRegister(opcode);
return(string.Format("LD {0},{1}", reg1, reg2));
}
else if ((opcode & 0xC0) == 0x80)
{
// Operation beetween accumulator and other registers
// Usually are identified by 10 ooo rrr where ooo is the operation and rrr is the source register
string reg = GetHalfRegister(opcode);
switch (opcode & 0xF8)
{
case 0x80: // ADD A,r
return(string.Format("ADD A,{0}", reg));
case 0x88: // ADC A,r
return(string.Format("ADC A,{0}", reg));
case 0x90: // SUB r
return(string.Format("SUB {0}", reg));
case 0x98: // SBC A,r
return(string.Format("SBC A,{0}", reg));
case 0xA0: // AND r
return(string.Format("AND {0}", reg));
case 0xA8: // XOR r
return(string.Format("XOR {0}", reg));
case 0xB0: // OR r
return(string.Format("OR {0}", reg));
case 0xB8: // CP r
return(string.Format("CP {0}", reg));
default:
throw new Exception("Wrong place in the right time...");
}
}
else if ((opcode & 0xC7) == 0x04) // INC r
{
string reg = GetHalfRegister((byte)(opcode >> 3));
return(string.Format("INC {0}", reg));
}
else if ((opcode & 0xC7) == 0x05) // DEC r
{
string reg = GetHalfRegister((byte)(opcode >> 3));
return(string.Format("DEC {0}", reg));
}
else if ((opcode & 0xC7) == 0x06) // LD r,nn
{
string reg = GetHalfRegister((byte)(opcode >> 3));
byte Value = _Memory.ReadByte(OpCodeAddress++);
return(string.Format("LD {0},{1}", reg, ShowData(Value)));
}
else if ((opcode & 0xC7) == 0xC0) // RET cc
{
return(string.Format("RET {0}", CheckFlag(opcode)));
}
else if ((opcode & 0xC7) == 0xC2) // JP cc,nn
{
Address = _Memory.ReadWord(OpCodeAddress);
string retValue = string.Format("JP {0},{1}", CheckFlag(opcode), ShowData(Address));
OpCodeAddress += 2;
return(retValue);
}
else if ((opcode & 0xC7) == 0xC4) // CALL cc,nn
{
Address = _Memory.ReadWord(OpCodeAddress);
string retValue = string.Format("JP {0},{1}", CheckFlag(opcode), ShowData(Address));
OpCodeAddress += 2;
return(retValue);
}
else if ((opcode & 0xC7) == 0xC7) // RST p
{
return(string.Format("RST {0}", ShowData((opcode & 0x38))));
}
else if ((opcode & 0xCF) == 0x01) // LD dd,nn
{
string reg = GetRegister(opcode, true);
ushort Value = _Memory.ReadWord(OpCodeAddress);
OpCodeAddress += 2;
return(string.Format("LD {0},{1}", reg, ShowData(Value)));
}
else if ((opcode & 0xCF) == 0x03) // INC ss
{
string reg = GetRegister(opcode, true);
return(string.Format("INC {0}", reg));
}
else if ((opcode & 0xCF) == 0x09) // ADD HL,ss
{
string reg = GetRegister(opcode, true);
return(string.Format("ADD HL,{0}", reg));
}
else if ((opcode & 0xCF) == 0x0B) // DEC ss
{
string reg = GetRegister(opcode, true);
return(string.Format("DEC {0}", reg));
}
else if ((opcode & 0xCF) == 0xC5) // PUSH qq
{
string reg = GetRegister(opcode, false);
return(string.Format("PUSH {0}", reg));
}
else if ((opcode & 0xCF) == 0xC1) // POP qq
{
string reg = GetRegister(opcode, false);
return(string.Format("POP {0}", reg));
}
else
{
switch (opcode)
{
case 0x00: // NOP
return("NOP");
case 0x02: // LD (BC),A
return("LD (BC),A");
case 0x07: // RLCA
return("RLCA");
case 0x08: // EX AF,AF'
return("EX AF,AF'");
case 0x0A: // LD A,(BC)
return("LD A,(BC)");
case 0x0F: // RRCA
return("RRCA");
case 0x10: // DJNZ offset
return(string.Format("DJNZ {0}", ShowData((sbyte)_Memory.ReadByte(OpCodeAddress++) + OpCodeAddress)));
case 0x12: // LD (DE),A
return("LD (DE),A");
case 0x17: // RLA
return("RLA");
case 0x18: // JR offset
return(string.Format("JR {0}", ShowData((sbyte)_Memory.ReadByte(OpCodeAddress++) + OpCodeAddress)));
case 0x1A: // LD A,(DE)
return("LD A,(DE)");
case 0x1F: // RRA
return("RRA");
case 0x20: // JR NZ,offset
return(string.Format("JR NZ,{0}", ShowData((sbyte)_Memory.ReadByte(OpCodeAddress++) + OpCodeAddress)));
case 0x22: // LD (nnnn),HL
Address = _Memory.ReadWord(OpCodeAddress);
OpCodeAddress += 2;
return(string.Format("LD ({0}),HL", ShowData(Address)));
case 0x27: // DAA
return("DAA");
case 0x28: // JR Z,offset
return(string.Format("JR Z,{0}", ShowData((sbyte)_Memory.ReadByte(OpCodeAddress++) + OpCodeAddress)));
case 0x2A: // LD HL,(nnnn)
Address = _Memory.ReadWord(OpCodeAddress);
OpCodeAddress += 2;
return(string.Format("LD HL,({0})", ShowData(Address)));
case 0x2F: // CPL
return("CPL");
case 0x30: // JR NC,offset
return(string.Format("JR NC,{0}", ShowData((sbyte)_Memory.ReadByte(OpCodeAddress++) + OpCodeAddress)));
case 0x32: // LD (nnnn),A
Address = _Memory.ReadWord(OpCodeAddress);
OpCodeAddress += 2;
return(string.Format("LD ({0}),A", ShowData(Address)));
case 0x37: // SCF
return("SCF");
case 0x38: // JR C,offset
return(string.Format("JR C,{0}", ShowData((sbyte)_Memory.ReadByte(OpCodeAddress++) + OpCodeAddress)));
case 0x3A: // LD A,(nnnn)
Address = _Memory.ReadWord(OpCodeAddress);
OpCodeAddress += 2;
return(string.Format("LD A,({0})", ShowData(Address)));
case 0x3F: // CCF
return("CCF");
case 0xC3: // JP nnnn
Address = _Memory.ReadWord(OpCodeAddress);
OpCodeAddress += 2;
return(string.Format("JP {0}", ShowData(Address)));
case 0xC6: // ADD A,nn
return(string.Format("ADD A,{0}", ShowData(_Memory.ReadByte(OpCodeAddress++))));
case 0xC9: // RET
return("RET");
case 0xCB: // CBxx opcodes
return(Disassemble_CB(_Memory.ReadByte(OpCodeAddress++)));
case 0xCD: // CALL nnnn
Address = _Memory.ReadWord(OpCodeAddress);
OpCodeAddress += 2;
return(string.Format("CALL {0}", ShowData(Address)));
case 0xCE: // ADC A,nn
return(string.Format("ADC A,{0}", ShowData(_Memory.ReadByte(OpCodeAddress++))));
case 0xD3: // OUT (nn),A
IOAddress = _Memory.ReadByte(OpCodeAddress++);
return(string.Format("OUT ({0}),A", ShowData(IOAddress)));
case 0xD6: // SUB nn
return(string.Format("SUB {0}", _Memory.ReadByte(OpCodeAddress++)));
case 0xD9: // EXX
// Each 2-byte value in register pairs BC, DE, and HL is exchanged with the
// 2-byte value in BC', DE', and HL', respectively.
return("EXX");
case 0xDB: // IN A,(nn)
// The operand n is placed on the bottom half (A0 through A7) of the address
// bus to select the I/O device at one of 256 possible ports. The contents of the
// Accumulator also appear on the top half (A8 through A15) of the address
// bus at this time. Then one byte from the selected port is placed on the data
// bus and written to the Accumulator (register A) in the CPU.
IOAddress = _Memory.ReadByte(OpCodeAddress++);
return(string.Format("IN A,({0})", ShowData(IOAddress)));
case 0xDD: // DDxx opcodes
return(Disassemble_DDFD("IX", ref OpCodeAddress));
case 0xDE: // SBC A,nn
return(string.Format("SBC A,{0}", _Memory.ReadByte(OpCodeAddress++)));
case 0xE3: // EX (SP),HL
return("EX (SP),HL");
case 0xE6: // AND nn
return(string.Format("AND {0}", _Memory.ReadByte(OpCodeAddress++)));
case 0xE9: // JP HL
return("JP HL");
case 0xEB: // EX DE,HL
return("EX DE,HL");
case 0xed: // EDxx opcodes
return(Disassemble_ED(ref OpCodeAddress));
case 0xEE: // XOR A,nn
return(string.Format("XOR A,{0}", _Memory.ReadByte(OpCodeAddress++)));
case 0xF3: // DI
return("DI");
case 0xF6: // OR nn
return(string.Format("OR {0}", _Memory.ReadByte(OpCodeAddress++)));
case 0xF9: // LD SP,HL
return("LD SP,HL");
case 0xFB: // EI
return("EI");
case 0xFD: // FDxx opcodes
return(Disassemble_DDFD("IY", ref OpCodeAddress));
case 0xFE: // CP nn
return(string.Format("CP {0}", _Memory.ReadByte(OpCodeAddress++)));
default:
throw new Exception(string.Format("Internal disassembler error. Opcode {0} not implemented.", opcode));
}
}
}
