https://blog.faceutil.com/2017/04/30/mame-%eb%a1%9d-%ec%95%a4-%ec%b2%b4%ec%9d%b4%ec%8a%a4-locknchase-%eb%8b%a4%ec%9a%b4-%eb%8b%a4%ec%9a%b4%eb%a1%9c%eb%93%9c-down-%e3%89%aa/