说明：  并口制作A/D转换接口电路,利用VC++提供的现成函数,可以直接控制和读写标准并口,具有无需打开机箱、开发成本低廉,制作方便等特点。
(Parallel production of A/D conversion interface circuit, using VC++ Provided ready-made function, you can directly control and read and write standard parallel port, with no need to open the chassis, the development of low-cost and easy production.)