void LoadFile()
        {
            //_data = File.ReadAllBytes(filename);

            _dirty = false;
            ReloadButton.Visibility    = Visibility.Hidden;
            FileNameBorder.BorderBrush = _savedBrush;
            FileNameLabel.Content      = System.IO.Path.GetFileName(_filename);

            // todo - detect file errors & report properly
            var block = new IntelHex().ReadAllBlocks(_filename).FirstOrDefault();

            if (block == null)
            {
                _data                = null;
                Display.Content      = "No data?";
                PlayButton.IsEnabled = false;
                return;
            }

            _data = block.Data;

            var length = _data.Length;

            //BytesLength.Content = string.Format("0x{0:X4} bytes\r\n\r\n0000.{1:X4}R", length, length - 1);
            Display.Content = string.Format("0x{0:X4} bytes at 0x{1:X4}\r\n{1:X4}.{2:X4}R",
                                            length, block.Address, block.Address + length - 1);

            PlayButton.IsEnabled = true;
        }
        void LoadFile()
        {
            //_data = File.ReadAllBytes(filename);

            _dirty = false;
            ReloadButton.Visibility = Visibility.Hidden;
            FileNameBorder.BorderBrush = _savedBrush;
            FileNameLabel.Content = System.IO.Path.GetFileName(_filename);

            // todo - detect file errors & report properly
            var block = new IntelHex().ReadAllBlocks(_filename).FirstOrDefault();
            if (block == null)
            {
                _data = null;
                Display.Content = "No data?";
                PlayButton.IsEnabled = false;
                return;
            }

            _data = block.Data;

            var length = _data.Length;
            //BytesLength.Content = string.Format("0x{0:X4} bytes\r\n\r\n0000.{1:X4}R", length, length - 1);
            Display.Content = string.Format("0x{0:X4} bytes at 0x{1:X4}\r\n{1:X4}.{2:X4}R",
                length, block.Address, block.Address + length - 1);

            PlayButton.IsEnabled = true;
        }