function SerialPort_ReadAllValues(
  BaseAddr: word;
  var I_CTS, I_DSR, I_RI, I_DCD: boolean): boolean;
begin
  result := SerialPort_ReadModemStatusValues(
  BaseAddr,
  I_CTS, I_DSR, I_RI, I_DCD);
end;

function SerialPort_ReadModemStatusValues(
  BaseAddr: word;
  var I_CTS, I_DSR, I_RI, I_DCD: boolean): boolean;
var
  Data: DWord;
  Addr: DWord;
begin
  if FHandle = INVALID_HANDLE_VALUE then exit;
  Addr := BaseAddr + 6;

  // read value on COM port if system IS NOT WinNT
  if Win32Platform <> VER_PLATFORM_WIN32_NT then
  begin
    try
      Case DataType of
        DataType_Byte :
          asm
            mov edx,Addr
            xor eax,eax
            in al,dx
            mov Data,eax
          end;
        DataType_Word :
          asm
            mov edx,Addr
            xor eax,eax
            in ax,dx
            mov Data,eax
          end;
        DataType_DWord:
          asm
            mov edx,Addr
            xor eax,eax
            in eax,dx
            mov Data,eax
          end;
      end;

    except
      result := false;
      exit;
    end;
  end
  else

  // read status value on COM port if system IS WinNT
  begin
    try
      if ZLIOStarted then
        Data := ZLIOPortRead(Addr, DataType)
      else
      begin
        Data := 0;
        result := false;
      end;
    except
      result := false;
      exit;
    end;
  end;

  // extract bits value for individual status line
  I_DCD := ((Data and 128) = 128);
  I_RI := ((Data and 64) = 64);
  I_DSR := ((Data and 32) = 32);
  I_CTS := ((Data and 16) = 16);
  result := true;

end;