PATA Device Cables – CompTIA A+ 220-1101 – 3.1

PATA is a common storage drive connection type on many legacy computers. In this video, you’ll learn about the PATA connector, storage drive connections, and the differences between a PATA and SATA data cables.


If you’re working with some legacy equipment, you may find storage devices inside of those computers that are connected with a ribbon cable just like this one. This is a connectivity called PATA or the Parallel AT Attachment. You might also see this referred to as Parallel ATA or simply ATA. The name AT Attachment comes from one of the original PCs created by IBM, which was the PC/AT and the AT attachment standard was the one used to connect drives within that system.

There have been a number of different versions of PATA through the years. And originally we didn’t even call it PATA. We called it IDE or Integrated Drive Electronics. This was a name created by the hard drive manufacturer Western Digital. They even had an updated version of IDE called Enhanced IDE or EIDE.

Through the years, the speeds of PATA continued to improve and you can find versions of PATA that range from 16 megabytes per second through 133 megabytes per second as a total throughput. There are also other drives that can connect to PATA, not just hard drives. You may even find CD-ROMs or DVD-ROMs that have a PATA connection on those as well. So although you may find motherboards and other equipment that are referring to an ATA drive or an IDE connection, today we refer to all of these as Parallel ATA or PATA.

Here’s an image of two different types of PATA cables. The one on the top is a 40 wire PATA cable and the one on the bottom is an 80 wire PATA cable. With both of these cables, there is a connection on one end that is a 40 pin connector for the motherboard and then there are two separate 40 pin connectors later on down the ribbon cable. On the 40 wire cable, the first device that you would connect is referred to as device 0 in the PATA standard. And the device connecting on the end of the cable is device one. Those two are swapped on the 80 wire cable. Device one is the first interface on the cable and device 0 is at the end.

The 40 wire cable was the original PATA cable. And then as we increase the speeds for PATA, we needed some way to decrease the amount of crosstalk between all of these wires, so we doubled the number of wires while keeping the number of pins on the connectors exactly the same. And this minimizes the crosstalk over these higher speeds that are used over 80 wire cables.

This is a 40 wire cable. And if we put an 80 wire cable right next to it, you can see visually they’re quite different, because the 80 wire cable obviously has twice the number of wires inside of the ribbon cable.

The PATA connectors are also quite large relative to the SATA connectors you might already be familiar with. This motherboard has a PATA connector right at the bottom and it’s quite large compared to the other connectors. If we zoom up, we can see all 40 pins inside of that connector. And you’ll notice that one of the pins is missing. That’s because this 40 pin connector is symmetrical. So that missing pin allows us to properly orient the cable into the right format when we’re plugging it into that connector. You might also notice there’s a notch at the bottom as well, which also helps when orienting the cable.

If you look at the end of the cable, you’ll see how this works. There’s a notch built into the PATA cable. And you can see in all of these PATA connectors that we are missing that hole that’s in the connection so that you couldn’t possibly plug it in in the wrong orientation. Here’s a better look at the interface on the motherboard. You can easily see that there is a notch at the bottom. And there’s your missing pin right in the middle of the PATA connector.

The connector that you would find on a storage device is identical to the connector that you would find on a motherboard. It’s this 40 pin symmetrical connector. You can see the notch in the bottom and the missing pin right in the middle of the PATA connector.

As I mentioned earlier, PATA is a legacy technology. It’s not one you’d commonly find in our newer systems. But if you do run into one of these 40 pin ribbon cables, then it’s probably a PATA device that you’re working with. Next to this PATA data cable is a SATA data cable. And you can see that it is much smaller than this very large ribbon cable used for PATA, and it takes up much less space inside of our systems than this older PATA technology.