(Using serial cable to realize dual-machine interconnection With the deepening of automated office, it is very urgent to set up a small local area network for office use in small and medium-sized enterprises. However, as you who have never been in contact with network technology, do you feel at a loss for the selection of office LAN, or feel unfathomable about some technical problems encountered in the networking process? Here, we have specially invited some classic cartoon characters that everyone is familiar with. Starting from the simplest dual-machine interconnection, we will tell you the stories related to network selection from the simple to the deep.)