电子钟电脑校正时间程序 （主要演示Vc环境下，串口可靠操作及相关通讯协议，完整代码，内有封装串口读写类，自主开发，并附开发说明文档）-Electronic clock computer correction time program (The main demo Vc environment, serial reliable operation and related communication protocols, complete code, with the package ser