Ａ／ Ｄ 或Ｄ／ Ａ 转化过程中， 往往要制作一专门的功能卡，但由于既要完成数、模的转化功能，又要考虑与微机配合衔接问题（ 接口地址及交叉电源的设置） ，一般来说制作和调试上比较烦琐。本篇提出利用现代计算机高速度运算的特点，利用程序直接通过串、并行口来与外界进行数据交换，从而达到简化Ａ／ Ｄ 或Ｄ／ Ａ 接口卡的硬件制作。 A / D or D / A conversion process, often have to make a special function card, but because it is necessary to complete the number of mold conversion function, but also to consider with the computer interface problems (interface address and cross power settings) In general, production and debugging more cumbersome. This article proposes the use of modern computer high-speed computing features, the use of programs directly through the serial and parallel port to exchange data with the outside world, so as to simplify the A / D or D / A interface card hardware production.