Appearance difference between serial port and parallel port

Difference between serial port and parallel port:

1. Difference in appearance: the socket of serial port is generally a pin, and the socket of parallel port is a pinhole. The most obvious difference is the serial com port and the parallel printer port on the computer.

2. The data and information transmission modes are different. The serial port can only be transmitted by single line, and the parallel port can be transmitted by multiple lines.

3. Different transmission speeds: the parallel port is faster than the serial port.

The data transmission rate of the serial port is 115kbps ~ 230kbps.

The parallel port transmission rate is generally 1mb/s, and the data transmission rate of the new VXI bus interface can be as high as 50mb/s.

4. Different transmission distances: the transmission distance of serial port is longer than that of parallel port.

The distance of serial communication is generally less than 50m.

The longest communication distance of parallel port can reach more than 1000 meters.

Serial interface is abbreviated as serial port, also known as serial communication interface or serial communication interface (usually COM interface), which is an extended interface using serial communication. Serial interface refers to the sequential transmission of data bit by bit. Its characteristic is that the communication line is simple. Only a pair of transmission lines can realize two-way communication (the telephone line can be directly used as the transmission line), which greatly reduces the cost. It is especially suitable for long-distance communication, but the transmission speed is slow.

Parallel interface refers to the interface standard that uses parallel transmission mode to transmit data. There are dozens of types from the simplest parallel data register or ASIC chips such as 8255 and 6820 to the more complex SCSI or IDE parallel interfaces. The interface characteristics of a parallel interface can be described from two aspects: 1 The width of the data channel transmitted in parallel, also known as the number of bits transmitted by the interface; 2. characteristics of additional interface control lines or interactive signals used to coordinate parallel data transmission. The width of data can be from 1 to 128 bits or more, and the most commonly used is 8 bits. 8 data bits can be transmitted at a time through the interface. The most commonly used parallel interface in the computer field is the LPT interface.