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This chapter is from the book

Interfaces and Cables

All storage devices in the computer are connected to the motherboard through cables. For your A+ exam, you just need to know a few basics about each cable. The term hot swappable means the drive can be connected and unplugged while the PC is running. Pin 1 is always the pin with the blue, red, or pink stripe. Both the device and the motherboard specify (usually with inhumanly small numbers) which side is pin 1. If no indication shows how to orient the cable, put pin 1 closest to the Molex power plug.

Table 31-2 compares the features of different drive interfaces.

Table 31-2 Drive Interfaces


Drives per Channel

Number of Pins

Hot Swappable

Need to Know (In Order of Importance)





Old standard.


Two drives per channel.

Jumpers assign master and slave drives.


8 or 16



Typically found on servers.


Drives are arranged along a bus-like cable with terminators on both ends.


Jumpers or dip switches assign drive numbers in binary.





Small cable improves air cooling.

Faster than PATA.

One drive per channel.

No jumpers, no master, and no slave.





Only for the FDD.

Pin 1 is usually oriented closest to the power connector, but look for the red stripe.

Some old FDD cables support multiple FDDs. They have a twist in the middle of the ribbon connectors.


Each day there is some homework. Today’s homework is to memorize the information in Table 31-2.


Each day there is also some funwork. It is important that you see the wider scope of a career as an A+ technician. Computer repair is not just pocket protectors, badly repaired glasses, and screwdrivers. It is home theater, surveillance systems, cell phones, credit cards, Facebook, Xbox, and World of Warcraft. You’re studying not for the sake of memorizing facts and information, but to add to your technical skill sets and learn to enjoy what you do. And let’s not start with how cool cybersecurity is. Can you imagine what the music and entertainment industry would look like without computer geeks?

Today, spend some quality time and observe all the ways computers touch our lives. Is there some “computery geekness” in medicine, military, banking, aerospace? How about a person using an iPad in a Starbucks to FaceTime a friend in Europe? Just imagine what goes on behind the scenes to make that happen. That is what we do. That is our world. We make that happen. That is some really cool stuff.

Here’s another example of the results of our world. Right now, I am drinking coffee paid for via credit card in a Barnes and Noble. I am listening to Pandora Radio (Daft Punk’s Tron: Legacy soundtrack) on my cell phone with noise-canceling headphones. I’m on my favorite laptop using a wireless mouse and Microsoft Word, and just got a text from one of my students about her super-fast gaming computer with six monitors. Do you see the bigger picture? This is our world, and it is awesome. Welcome.

Study Resources

For today’s exam topics, refer to the following resources for more study:

  • Cisco Networking Academy Curriculum. Chapters 3 and 11
  • CompTIA A+ Cert Guide by Mark Edward Soper, Scott William Mueller, and David L. Prowse. Chapters 3, 7, and 12
  • The Complete A+ Guide to PC Repair by Cheryl Ann Schmidt. Chapter 7
  • The Comprehensive Guide to Managing and Maintaining Your PC by Jean Andrews. Chapter 8
  • All-in-One CompTIA Certification Exam Guide, Seventh Edition by Mike Meyers. Chapters 11 and 12
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