这是一个利用at指令在vc++环境编写利用笔记本的com口控制modem拨打公用电话网电话的程序，程序调试可用。-This is a use at command in vc++ Environment prepared to use the notebook to control the com port PSTN modem dial telephone procedures can be used for program debugging.

手机AT modem的处理流程,包含at 命令的读取,解析和编码.-process of at modem in phone,including read data from com port, decode at commad, and incode at command to phone.