https://blog.faceutil.com/2017/03/27/msx-%ec%8a%88%ed%8d%bc-%ec%8a%a4%eb%84%a4%ec%9d%b4%ed%81%ac-super-snake-%e3%82%b9%e3%83%91%e3%82%b9%e3%83%8d%e3%82%af-%e3%88%80/