Difference between Serial Port and Parallel Port

Computer ports are like gateways that allow devices to connect and communicate with the computer system. These ports are physical sockets on the computer where we can plug-in various peripherals. Each port type is designed for a specific function. For example, USB ports connect devices like keyboards and mouse, Ethernet ports provide internet access, and display ports connect monitors. In this article we will see serial port and parallel port in detail.

What is Serial Port

A serial port is an interface that is used for connecting the serial lines to attain the serial communication. These ports can dock a 9-pin D-shaped connector that connects to the transmission line, is called DB-9 connectors. Serial communication gained by single wire and only the single stream of data is transferred from one end to other. Therefore, like parallel transmission, in serial transmission data speed mismatch is not a problem. The length of the wire can be increased as needed. The transmission speed of serial port is comparatively lower than that of a parallel port. Serial ports are typically implemented in the modems, connecting devices, controllers, mouse and also in security cameras. DB-9 pin connector diagram is given below.

Advantages of Serial Port

• Serial ports can transmit data over longer distances compared to parallel ports, making them suitable for applications that require communication over extended cable length.

• Serial ports use the fewer wires and a simpler circuitry resulting in a lower manufacturing costs and the easier implementation in a various devices and systems.

• Serial communication is a less susceptible to the crosstalk and a electromagnetic interference ensuring the more reliable data transmission especially in a noisy environments.

Disadvantages of Serial Port

• Serial ports typically have a slower data transfer speeds compared to the modern interfaces like a USB or Ethernet limiting their usefulness in a high bandwidth applications.

• Many new computers and devices no longer include a built in serial ports requiring the additional adapters or a converters for the connectivity with a legacy equipment.

• Serial ports often require a manual configuration of the parameters like baud rate and parity, making them a less user friendly compared to the modern auto configuring interfaces.

What is Parallel Port

Unlike serial port, a parallel port can move a set of 8 bits at a time on eight different wires. That's why it is faster in comparison to the serial communication. Unlike a serial port, it uses the 25 pin connector that is called a DB-25 connector. To eliminate a cross talk and errors all the bitstreams need to transfer a data at the same speed in a parallel communication. But that is impractical. For this reason the transmission lines are preferred to be short in a parallel communication. Parallel ports are typically the implemented in zip drives, printers, hard drives, CD-ROM drives etc. DB-25 pin connector diagram is given above.

Advantages of Parallel Port

• Parallel ports can transmit multiple bits simultaneously, allowing for faster data transfer speeds compared to traditional serial ports, especially for short-distance communications.

• Parallel ports have a straightforward hardware interface, making them easy to implement and interface with various devices, particularly in embedded systems and industrial applications.

• Many parallel port implementations support DMA, allowing for efficient data transfer between peripherals and system memory without significant CPU involvement.

Disadvantages of Parallel Port

• The Parallel ports are susceptible to a signal degradation over a longer distances restricting their effective cable length to the typically less than 2 meters which limits their use in a long distance communications.

• Parallel port connectors are bulkier compared to a modern interfaces occupying more space on the devices and making them less suitable for a compact or the portable equipment.

• The multiple data lines in parallel ports can generate more electromagnetic interference, potentially causing issues in sensitive electronic environments and requiring additional shielding.

Difference between Serial port and Parallel Ports