public void OnPower()
    {
        IsStarting = true;
        TextAsset code = Resources.Load("start") as TextAsset;

        // draw logo
        Texture2D logo    = Resources.Load("logo") as Texture2D;
        int       xcenter = (DisplaySystem.WIDTH - logo.width) / 2;
        int       ycenter = (DisplaySystem.HEIGHT + logo.height) / 2;

        _screen.SetFontColor(Color.white);
        _screen.SetBackColor(Color.black);
        _screen.Clear();
        _screen.DrawImage(xcenter, ycenter, logo.width, logo.height, logo.GetPixels());

        _runner.RunCode(code.text);
    }