public DasmUtils(Z80CPU cpu, OnRDBUS reader)
{
Object = cpu;
memReader = reader;
}
public static string GetMnemonic(OnRDBUS MemReader, int Addr, bool Hex, out int MnemLength)
{
string sbuf;
int pos;
int CurPtr = 0x0000;
byte selcode = MemReader((ushort)(Addr + CurPtr));
string Mnem;
MnemLength = 1;
string PrefixReg = "*prefix*";
int PlusMinusOffsetIndex = 0;
if (selcode == 0xCB)
{
CurPtr++;
MnemLength++;
Mnem = CBhZ80Code[MemReader((ushort)(Addr + CurPtr))];
}
else if (selcode == 0xED)
{
CurPtr++;
MnemLength++;
Mnem = EDhZ80Code[MemReader((ushort)(Addr + CurPtr))];
if (Mnem.Length == 0) Mnem = "*NOP";
}
else if ((selcode == 0xDD) || (selcode == 0xFD))
{
REPREFIX_DDFD:
selcode = MemReader((ushort)(Addr + CurPtr));
if (selcode == 0xDD) PrefixReg = "IX";
else PrefixReg = "IY";
CurPtr++;
PlusMinusOffsetIndex = 1;
MnemLength++;
if (MemReader((ushort)(Addr + CurPtr)) == 0xCB)
{
CurPtr++;
MnemLength++;
PlusMinusOffsetIndex = 0;
Mnem = DDFDCBhZ80Code[MemReader((ushort)(Addr + CurPtr + 1))];
if (Mnem.Length == 0) MnemLength++; // ??? for CBh
}
else if (MemReader((ushort)(Addr + CurPtr)) == 0xED)
{
CurPtr++;
MnemLength++;
Mnem = EDhZ80Code[MemReader((ushort)(Addr + CurPtr))];
if (Mnem.Length == 0) Mnem = "*NOP";
if (Mnem[0] != '*') Mnem = "*" + Mnem; // mark undocumented as "*"...
}
else if ((MemReader((ushort)(Addr + CurPtr)) == 0xDD) || (MemReader((ushort)(Addr + CurPtr)) == 0xFD)) // DD/FD, DD/FD
{
goto REPREFIX_DDFD;
}
else Mnem = DDFDhZ80Code[MemReader((ushort)(Addr + CurPtr))];
if (Mnem.Length == 0) Mnem = "*" + DirectZ80Code[MemReader((ushort)(Addr + CurPtr))];
}
else Mnem = DirectZ80Code[MemReader((ushort)(Addr + CurPtr))];
if (Mnem.IndexOf("$") < 0) return Mnem;
do
{
if (Mnem.IndexOf("$R") >= 0) // Prefix register
{
pos = Mnem.IndexOf("$R");
if (Mnem.Length <= (pos + 1 + 1)) // ixl/ixh -> xl/xh !!!!!
{
Mnem = Mnem.Remove(pos, 2);
Mnem = Mnem.Insert(pos, PrefixReg);
}
else if ((Mnem[pos + 2] == 'L') || (Mnem[pos + 2] == 'H'))
{
Mnem = Mnem.Remove(pos, 2);
Mnem = Mnem.Insert(pos, "" + PrefixReg[1]);
}
else
{
Mnem = Mnem.Remove(pos, 2);
Mnem = Mnem.Insert(pos, PrefixReg);
}
}
if (Mnem.IndexOf("$PLUS") >= 0) // PrefixReg+-offset
{
sbyte val = (sbyte)MemReader((ushort)(Addr + (CurPtr + PlusMinusOffsetIndex)));
int uval = val;
if (val < 0) uval = -uval;
if (val < 0)
{
if (Hex) sbuf = "-#" + uval.ToString("X2"); //sprintf(buf, "-"Z80ASMHEX"%02X", int(uval));
else sbuf = "-" + uval.ToString(); //sprintf(buf, "-%i", int(uval));
}
else
{
if (Hex) sbuf = "+#" + uval.ToString("X2"); //sprintf(buf, "+"Z80ASMHEX"%02X", int(uval));
else sbuf = "+" + uval.ToString(); //sprintf(buf, "+%i", int(uval));
}
pos = Mnem.IndexOf("$PLUS");
Mnem = Mnem.Remove(pos, 5);
Mnem = Mnem.Insert(pos, sbuf);
MnemLength++;
CurPtr++;
}
if (Mnem.IndexOf("$S") >= 0) // Internal bits value
{
byte code = MemReader((ushort)(Addr + CurPtr));
int bitadr = (code & 0x38) >> 3;
sbuf = bitadr.ToString(); //sprintf(buf, "%i", int(bitadr));
pos = Mnem.IndexOf("$S");
Mnem = Mnem.Remove(pos, 2);
Mnem = Mnem.Insert(pos, sbuf);
}
if (Mnem.IndexOf("$W") >= 0) // 2byte value
{
ushort val = (ushort)(MemReader((ushort)(Addr + CurPtr + 1)) + 256 * MemReader((ushort)(Addr + CurPtr + 2)));
if (Hex) sbuf = "#" + val.ToString("X4"); // sprintf(buf, Z80ASMHEX"%04X", int(val));
else sbuf = val.ToString(); // sprintf(buf, "%i", int(val));
pos = Mnem.IndexOf("$W");
Mnem = Mnem.Remove(pos, 2);
Mnem = Mnem.Insert(pos, sbuf);
MnemLength += 2;
}
if (Mnem.IndexOf("$N") >= 0) // 1byte value
{
byte val = MemReader((ushort)(Addr + CurPtr + 1));
if (Hex) sbuf = "#" + val.ToString("X2"); //sprintf(buf, Z80ASMHEX"%02X", int(val));
else sbuf = val.ToString(); //sprintf(buf, "%i", int(val));
pos = Mnem.IndexOf("$N");
Mnem = Mnem.Remove(pos, 2);
Mnem = Mnem.Insert(pos, sbuf);
MnemLength++;
}
if (Mnem.IndexOf("$T") >= 0) // Internal bits value ($S)*8
{
byte code = MemReader((ushort)(Addr + CurPtr));
int rstadr = ((code & 0x38) >> 3) * 8;
if (Hex) sbuf = "#" + rstadr.ToString("X2"); //sprintf(buf, Z80ASMHEX"%02X", int(rstadr));
else sbuf = rstadr.ToString(); //sprintf(buf, "%i", int(rstadr));
pos = Mnem.IndexOf("$T");
Mnem = Mnem.Remove(pos, 2);
Mnem = Mnem.Insert(pos, sbuf);
}
if (Mnem.IndexOf("$DIS") >= 0) // 1byte offset value
{
sbyte val = (sbyte)MemReader((ushort)(Addr + CurPtr + 1));
// int adr = (Addr + 2) + val;
int adr = (Addr + 2 + CurPtr) + val;
adr = (ushort)adr;
if (Hex) sbuf = "#" + adr.ToString("X4"); //sprintf(buf, Z80ASMHEX"%04X", int(adr));
else sbuf = adr.ToString(); //sprintf(buf, "%i", int(adr));
pos = Mnem.IndexOf("$DIS");
Mnem = Mnem.Remove(pos, 4);
Mnem = Mnem.Insert(pos, sbuf);
MnemLength++;
}
} while (Mnem.IndexOf("$") >= 0);
return Mnem;
}
