/// <summary>
/// The OTDR instruction.
/// </summary>
byte OTDR()
{
FetchFinished();
var portNumber = Registers.C;
var address = Registers.HL;
var value = ProcessorAgent.ReadFromMemory(address.ToUShort());
ProcessorAgent.WriteToPort(portNumber, value);
Registers.HL = address.Dec();
var counter = Registers.B;
counter = counter.Dec();
Registers.B = counter;
Registers.ZF = (counter == 0);
Registers.NF = 1;
Registers.SF = counter.GetBit(7);
SetFlags3and5From(counter);
if (counter != 0)
{
Registers.PC = Registers.PC.Sub(2);
return(21);
}
return(16);
}
/// <summary>
/// The OTDR instruction.
/// </summary>
byte OTDR()
{
FetchFinished();
var portNumber = Registers.C;
var address = Registers.HL;
var value = ProcessorAgent.ReadFromMemory((ushort)address);
ProcessorAgent.WriteToPort(portNumber, value);
Registers.HL--;
var counter = Registers.B;
counter = (byte)(counter - 1);
Registers.B = counter;
Registers.ZF = (counter == 0);
Registers.NF = 1;
Registers.SF = counter.GetBit(7);
SetFlags3and5From(counter);
if (counter != 0)
{
Registers.PC = (ushort)(Registers.PC - 2);
return(21);
}
return(16);
}
/// <summary>
/// The OUT (C),0 instruction.
/// </summary>
byte OUT_C_0()
{
FetchFinished();
ProcessorAgent.WriteToPort(Registers.C, 0);
return(12);
}
/// <summary>
/// The OUT (n),A instruction.
/// </summary>
byte OUT_n_A()
{
var portNumber = ProcessorAgent.FetchNextOpcode();
FetchFinished();
ProcessorAgent.WriteToPort(portNumber, Registers.A);
return(11);
}