CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

1.2. Comparing Cable Types

In this section, you examine several different types of cables and discover the uses of each type. Some of the cables are used inside your computer, and others are external. After you complete this section, you should be able to identify the basic types of cables and where they are used.

1.2.1. Ribbon

Ribbon cables are often used to connect components inside a computer, such as hard disk drives and floppy disk drives. They are made up of several wires laid out parallel to each other in such a way that they resemble a ribbon, as shown in Figure 1-1. These cables usually have keyed connectors on them that prevent them from being incorrectly connected to devices. Note the small tab halfway down the edge of the black connector: This tab matches a groove on the device that it is attached to.

Figure 1.1. Ribbon cables are usually found inside your computer.

You can read more about ribbon cables when connecting storage devices inside your computer, which is covered in Book II, Chapter 5.

1.2.2. Twisted pair

Twisted pair cables consist of three or four pairs of wires. The grading level is based on how the wires are arranged inside the cable, rather than the number of wires. In Figure 1-2, you can see how each pair of wires is twisted together at a specific rate, and then how all the pairs are twisted together. This procedure reduces the effect of cross talk ...