https://blog.faceutil.com/2017/04/28/%ec%9c%88%eb%8f%84%ec%9a%b0-7%ec%9c%88%eb%8f%84%ec%9a%b0-8-%ed%95%98%ec%9d%b4%ed%8d%bc%ed%84%b0%eb%af%b8%eb%84%90hyperterminal-%eb%8b%a4%ec%9a%b4-%ec%95%88%eb%82%b4-%e3%82%82/