Section 1.8: Input and Peripherals Devices

Unlimited number of devices can be connected to your computer. The most common devices besides mouse and keyboard include:

  • Bar code reader: Used for scanning barcodes.
  • Web and digital camera: Multimedia devices that are used to input video and audio. They commonly use USB or FireWire Connections.
  • Biometric devices: These devices are authenticating devices that authenticate a user on the basis of their unique physical features such as thumb, fingers, and retina, as shown in Figure 46:

Figure 46

  • Touch screen: Desktop and laptop devices that allow you to interact with the software by touching the screen.
  • KVM switch: This device allows you to use one keyboard, mouse, or a video display with a number of computers, as shown in Figure 47.

Figure 47

Most of these devices can be connected to the computer using Expansion slots. There are three types of expansion slots: ISA, PCI, and AGP.

Each of these types is different in their appearance and function. Some common types of connector used to connect the devices are:

Figure 48

  • DB: The D shaped connector having a metal ring and a set of pins, as shown in Figure 48. They are named on the basis of the pins used in them such as DB-25, DB-9, and DB-15. They can be either parallel or serial.
  • RJ (Registered jack): This is a plastic plug with small metal tabs, as shown in Figure 49. The RJ-11 connector has two metal tabs, RJ-14 has four, and RJ-45 has 8 tabs. The RJ -45 is used for Ethernet 10BaseT/100BaseT networking.

Figure 49

  • BNC: This connector consists of a metal wire surrounded by a shielding, as shown in Figure 50. It is used for 10Base2 Ethernet networking. It is always serial.

Figure 50

Figure 51

  • Centronics: This connector consists of a plastic block with metal tabs that is surrounded by a D shaped ring, as shown in Figure 51. It used to connect a parallel printer cable to the printer.