public override ExecutionResult ExecuteInstruction(MmixComputer mmixComputer, Tetra tetra)
{
mmixComputer.rBB = mmixComputer.Registers[255];
// TODO there is a lot more to be understood here - http://mmix.cs.hm.edu/doc/instructions-en.html#TRAP
// for now, XYZ == 0 terminates the program.
if (tetra.Y == Constants.Fputs && tetra.Z == 1)
{
// get pointer from $255
var address = mmixComputer.Registers[255].ToLong();
byte letter;
var letters = new List <byte>();
do
{
letter = mmixComputer.Memory[address];
letters.Add(letter);
address++;
} while (letter != 0x00);
Console.Write(Encoding.ASCII.GetString(letters.ToArray()));
}
if (tetra.ToInt() == 0)
{
return(ExecutionResult.HALTED);
}
return(ExecutionResult.CONTINUE);
}
public override ExecutionResult ExecuteInstruction(MmixComputer mmixComputer, Tetra tetra)
{
var reg = mmixComputer.Registers[tetra.X];
ulong a = mmixComputer.Registers[tetra.Y].ToULong() + mmixComputer.Registers[tetra.Z].ToULong();
var bytes = mmixComputer.ReadOcta(a);
reg.Store(bytes);
return(ExecutionResult.CONTINUE);
}
public override ExecutionResult ExecuteInstruction(MmixComputer mmixComputer, Tetra tetra)
{
// register to store into
var reg = mmixComputer.Registers[tetra.X];
// multiply by 4 as ops are 4 bytes wide
long relativeAddress = 4 * (tetra.Y + tetra.Z);
// sign check as there isn't a ulong + long overload that handles negatives (I think)
ulong address;
if (relativeAddress > 0)
{
address = mmixComputer.PC + (ulong)relativeAddress;
}
else
{
address = mmixComputer.PC - (ulong)(-relativeAddress);
}
reg.Store(address);
return(ExecutionResult.CONTINUE);
}
public abstract ExecutionResult ExecuteInstruction(MmixComputer mmixComputer, Tetra tetra);
public ExecutionResult Execute(MmixComputer mmixComputer, Tetra tetra)
{
//Console.WriteLine(Symbol);
return(ExecuteInstruction(mmixComputer, tetra));
}
