public void RunROM(rom SelfROM, ram SelfRAM)
{
//Load ROM
ROM = SelfROM;
RAM = SelfRAM;
PC_Register = 0x8000;
//Run ROM
IsRunning = true;
byte CurrentByte;
while (IsRunning)
{
//Get byte at Program Counter
CurrentByte = ROM.GetByte(PC_Register);
//Turn Byte into Instruction
switch (CurrentByte)
{
case 0x0:
BRKInstruction(CurrentByte);
break;
case 0x10:
BPLInstruction(CurrentByte);
break;
case 0x18:
CLCInstruction(CurrentByte);
break;
case 0x20:
JSRInstruction(CurrentByte);
break;
case 0x24:
BITZePgInstruction(CurrentByte);
break;
case 0x30:
BMIInstruction(CurrentByte);
break;
case 0x38:
SECInstruction(CurrentByte);
break;
case 0x45:
EORZePgInstruction(CurrentByte);
break;
case 0x4C:
JMPAbsInstruction(CurrentByte);
break;
case 0x50:
BVCInstruction(CurrentByte);
break;
case 0x58:
CLIInstruction(CurrentByte);
break;
case 0x60:
RTSInstruction(CurrentByte);
break;
case 0x69:
ADCImmInstruction(CurrentByte);
break;
case 0x70:
BVSInstruction(CurrentByte);
break;
case 0x78:
SEIInstruction(CurrentByte);
break;
case 0x85:
StaZePgInstruction(CurrentByte);
break;
case 0x86:
StxZePgInstruction(CurrentByte);
break;
case 0x8D:
StaAbsInstruction(CurrentByte);
break;
case 0x8E:
StxAbsInstruction(CurrentByte);
break;
case 0x90:
BCCInstruction(CurrentByte);
break;
case 0x9A:
TXSInstruction(CurrentByte);
break;
case 0xA0:
LDYImmInstruction(CurrentByte);
break;
case 0xA2:
LDXImmInstruction(CurrentByte);
break;
case 0xA5:
LdaZePgInstruction(CurrentByte);
break;
case 0xA9:
LDAImmInstruction(CurrentByte);
break;
case 0xAA:
TAXInstruction(CurrentByte);
break;
case 0xAD:
LdaAbsInstruction(CurrentByte);
break;
case 0xB0:
BCSInstruction(CurrentByte);
break;
case 0xB8:
CLVInstruction(CurrentByte);
break;
case 0xBD:
LdaAbsXInstruction(CurrentByte);
break;
case 0xC0:
CPYImmInstruction(CurrentByte);
break;
case 0xC9:
CMPImmInstruction(CurrentByte);
break;
case 0xCA:
DEXInstruction(CurrentByte);
break;
case 0xE0:
CPXImmInstruction(CurrentByte);
break;
case 0xEA:
NOPInstruction(CurrentByte);
break;
case 0xED:
INXInstruction(CurrentByte);
break;
case 0xD0:
BNEInstruction(CurrentByte);
break;
case 0xD8:
CLDInstruction(CurrentByte);
break;
case 0xF0:
BEQInstruction(CurrentByte);
break;
case 0xF8:
SEDInstruction(CurrentByte);
break;
default:
Debug.WriteLine("OpCode not implemented!!!");
throw new NotImplementedException("OpCode not implemented!!!");
}
PC_Register += InstructionLength;
Debug.WriteLine("PC Register: " + PC_Register.ToString("X"));
}
}
public void ADCImmInstruction(byte Instruction)
{
InstructionLength = 2;
byte Fetched = ROM.GetByte(PC_Register + 1);
int Carry = Status_Register.HasFlag(StatusFlags.C) ? 1 : 0;
byte Sum = (byte)(A_Register + Fetched + Carry);
A_Register = Sum;
if (A_Register == 0)
{
Status_Register |= (StatusFlags)StatusFlags.Z;
}
if ((A_Register & (1 << 7 - 1)) != 0)
{
Status_Register |= (StatusFlags)StatusFlags.N;
}
if ((~(A_Register ^ Fetched) & (A_Register ^ Sum) & 0x80) != 0)
{
Status_Register |= (StatusFlags)StatusFlags.V;
}
if ((A_Register + Fetched + Carry) > 0xFF)
{
Status_Register |= (StatusFlags)StatusFlags.C;
}
Debug.WriteLine("ADC #" + Fetched + " - Identifier byte: " + Instruction);
}