这是一个多路温度巡检仪，包括温度上下限的设定和显示等。- introduced a multi-channel and wide range temperature data logging instrument of the main circuit structure and working principle, the whole system in order to AT89C51 single chip at the core

Video-DVM is a very cheap DVM that shows how an output as complex as a videocomposite signal can be generated entirely in software: two I/O pins and three resistors are all the hardware required. Connected to any TV set it displays voltages, included

59秒精确定时，记录一分钟内的任意时刻，定时器是一个多任务定时提醒软件，安装于电脑上或其它所需要的地方。-59 seconds accurate timing, logging one minute any time, the timer is a multi-task time to remind the software installed on your computer or other necessary places.

实现简单的聊天功能，包括在线聊天消息记录。-Achieve a simple chat features, including online chat message logging.