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多年来个人计算机的串口与并口的功能和结构并没有什么变化。串口的出现是在1980年前后,数据传输率是115Kbps-230Kbps,串口一般用来连接鼠标和外置Modem;并口的数据传输率比串口快8倍,标准并口的数据传输率为IMbps,一般用来连接打印机、扫描仪等。原则上每一个外设必须插在一个接口上,如果所有的接口均被占用,就只能通过添加插卡来增加接口。串并口不仅速度有限,而且在使用上很不方便。为此,人们开始寻求新的接口标准。于是就有了今天的USB和IEEE 1394。
Over the years personal computer’s serial port and parallel port function and structure and no change. Serial port appears before and after 1980, the data transfer rate is 115Kbps-230Kbps, the serial port is generally used to connect the mouse and external Modem; parallel port data transfer rate eight times faster than the serial port, the standard parallel port data transfer rate IMbps, the general use To connect the printer, scanner and so on. In principle, each peripheral must plug in an interface, if all the interfaces are occupied, you can only add the interface card by adding a card. Serial and parallel port not only speed is limited, but also very inconvenient in use. To this end, people began to seek new interface standards. So there is today’s USB and IEEE 1394.