https://blog.faceutil.com/2017/03/30/msx-%ed%95%8f%ed%8f%b4-pitfall-%ed%94%bc%ed%8a%b8%ed%8f%b4-%e3%83%94%e3%83%83%e3%83%88%e3%83%95%e3%82%a9%e3%83%ab-%d1%8c/