Understanding Computer IO Ports

Input/ Output port enables you to connect hardware devices such as the keyboard, flash drives, mouse, printer and scanners to the system. It is the entry and exit point for data from the system. A port is used to connect the system and a device together, using a connecting cable, so that they can communicate together. The different ports available are usually located at the back of the system case or they may also be located at the front side of the system case.

Types of ports:

The ports have different shapes and size and so before purchasing a device you must check if you can attach a device to the system using the port available on the system. Based on this the ports are classified into different types:

  1. Serial ports: A serial port is like a single lane road that sends and receives one bit of data at a time. Thus, eight bits of data in one byte travel one bit at a time, one behind the other. The serial port connector is also known as the communication or Com port and can have 9 or 25 pins. A serial port is used to connect devices such as the mouse, plotters, PDA docking devices, bar code readers, scales, device control circuits and external modems to the system.
  2. Parallel ports: A parallel port is like an eight lane road that transmits eight bits of data at a time. It is like eight cars moving on a wide road side by side. The parallel port connector has 25 pins to connect devices such as printers, scanners, external hard drives and tape drive backup devices.
  3. PS/2 ports: The PS/2 port is used to connect the keyboard and mouse to the system. The ports are available in a colour that matches the colour of the plug connecting the mouse and keyboard. This port uses 6 pins to connect the devices.
  4. Universal Serial Bus (USB) Ports: The USB port is a rectangular port that is used to connect a variety of devices to the system. The USB port also supplies power to the device such as web camera, if the device does not use an external power source. To use the USB device you must just plug the device into the USB port, as most USB device offer Plug-and-play support. You must install the USB drivers before using the USB port.
  5. Infrared ports: Devices use the infrared ports to communicate with the system without using wires. The devices send out infrared signals that enter the system through this port.
  6. Bluetooth ports: Bluetooth is technology which allows wireless communication between devices within a ranged distance. A Bluetooth adapter is required for the computer and a Bluetooth compatible device to communicate through Bluetooth
  7. IEEE 1394 BUS: The Institute of Electrical & Electronics Engineering (IEEE) 1394 is a standard for the external bus that enables fast and high serial data transfer between the system and the connected devices. The IEEE can transfer data at the speed of about 400 Mbps.

Troubleshooting problems with the I/O ports:

Problems with the I/O ports result in errors being displayed while using the device, the operating system may crash while using the device. The device may also not function if the device IRQ line conflicts with another device. A hardware device may not work if there is some problem with the I/O port, the system or with the device itself.

  1. Check if the device is properly connected to the port.
  2. Remove the device from the port and connect it to another vacant port.
  3. Scan the system for viruses.
  4. Uninstall and reinstall the device drivers.
  5. Check if the card for the port is properly attached to the motherboard.
  6. In the BIOS settings, check if that particular port is enabled.
  7. Try attaching the device to a different system to check if the device is functioning properly, if the device works on the other system then the port is spoilt.
  8. Troubleshoot the device.