PC Hardware in a Nutshell, 3rd Edition

Ribbon cable fundamentals

On first glance, ribbon cables appear to be dead standard. They’re nearly all light gray nowadays, although you may encounter light blue, white, or rainbow ribbon cables on older systems. All of them use a contrasting colored stripe to indicate pin 1 (brown in the case of the rainbow cables). They use only two types of connectors (described later in this section), both of which are female and only one of which is commonly used nowadays. For a ribbon cable with a given number of wires, it might seem that the only distinguishing features are how long the cable is and whether it has connectors for two devices or just one. Problems may arise, however, if incompatible keying methods are used on the two connectors that need to mate.

Warning

So-called “round” ribbon cables have recently become popular, particularly with makers that cater to gamers and other enthusiasts. A round ribbon cable is simply a standard cable that has been sliced longitudinally into smaller groups of wires. For example, a standard flat 40-wire IDE ribbon cable might be sliced into ten 4-wire segments, which are then bound with cable ties or otherwise secured into a more-or-less round package. The advantage to round ribbon cables is that they reduce clutter inside the case and improve airflow. The disadvantage is that doing this damages signal integrity on the individual wires because signal-bearing wires are put into closer proximity than intended. We recommend you avoid round ribbon ...