一、前言目前,国内已有各类微型机,大致可分为学习用单板机、个人计算机、通用系统三类。这三类微型机还不能满足过程控制用户及专用设备制造厂的需要,主要问题是缺少合适的过程输入/输出通道,结构上也难以扩充。我们吸收国外先进技术, I. Foreword At present, there are all kinds of mini-computers in China that can be divided into three types: learning single-board computers, personal computers and general-purpose systems. These three types of microcomputers are not yet capable of meeting the needs of process control users and specialty equipment manufacturers. The main problem is the lack of suitable process input / output channels, which is also structurally difficult to scale. We absorb foreign advanced technology,