What Are the Two Types of PATA Cables?

The two types of Parallel Advanced Technology Attachment cables, also known as Integrated Drive Electronics and Intelligent Drive Electronics, vary in how many conductors are built in to the cable. The two nearly identical looking types are referred to as 40-conductor and 80-conductor cables. PATA was the primary means for connecting internal hard drives and optical drives to computers until the Serial ATA standard replaced it. The term PATA was retroactively introduced after the introduction of SATA.

PATA 40-conductor cables were the first of the two cable types to be introduced and can be used with IDE devices that support transfer speeds of up to 33 Mbps. The PATA 40-conductor cable features three plugs that can be used to connect two devices to a computer over a single motherboard port. It is highly prone to electrical interference through the cable, however, because of the ribbon design's lack of shielding. The 40-conductor version is limited to a maximum 18-inch cable size, as shorter cables are less prone to interference.

PATA 80-conductor cables are a revision to the cable standard that can handle data transfers of up to 133 Mbps and have improved insulation against electrical interference. The 80-conductor cables improve over major problems in the initial version and should be used whenever possible. The 80-conductor cable doesn't feature additional connection wires. Instead, the additional 40 conductors are in the cable to separate the wires that actually transfer data and reduce electrical interference. While the 80-conductor revision is less prone to interference, it still is limited to 18-inches.

Devices designed for 40-conductor PATA cables will work with 80-conductor PATA cables. However, devices that support the higher-speed connection offered by 80-conductor cables should not use the 40-conductor cables. It's possible to connect one 33 Mbps peripheral device and a 150 Mbps peripheral device to the same 80-conductor cable. Visually, you can tell the two apart by inspecting the connectors: the 80-conductor version is missing a pin slot whereas the 40-conductor version isn't. Additionally, the 80-conductor version is a few millimeters wider and has twice as many half-sized wire bumps on the ribbon compared to its predecessor.

Floppy drive channel cables look similar to PATA cables, but are a different standard. Floppy cables use a similar-looking ribbon to PATA and feature 34 connector pins compared to PATA's 40. The floppy cables and ports are marginally smaller than PATA cables and ports. Without directly comparing the two types of cables, the similar-sized floppy cables can be easily mistaken for PATA cables. The floppy connection port may be located next to the motherboard's PATA ports, making it easy to tell the two port types apart by size.