Device Cables

Floppy drives may be fading into history, but one myth has stuck around nearly since the beginning: the "red stripe" indicating pin 1 on the data cable does not always face the same side as the power connector. As seen below, both drives have pin 1 on the "left" side as seen when facing the connector, but the top drive has the power connection on the "right" side when viewed from this same perspective. The photo below also shows the data cable orientation for all drives we've tested: pin one is on the same side regardless of the locations of other connections.

Most floppy cables are now "keyed" with a block below the connector, but many floppy drives such as the bottom one in the photo above are designed to defeat this protection.

ATAPI and Ultra ATA drives have pin 1 on the "other" side of the connector as seen when facing it - on the right in the photo below - it's been many years since we've seen a nonstandard drive. A key is located on the top of all 80-conductor ATA cables to prevent upside-down insertion.

Floppy and ATA drive power connectors are keyed to fit one way. Of these two connector styles, floppy power is easiest to force on the "wrong way" and should be visually inspected to ensure proper placement.

Serial ATA power and data cables are keyed on the sides as seen on the drive below. Some Serial ATA drives are also able to accept older 4-pin ATA power connectors - the sticker warns that builders should chose either serial ATA or "legacy" power, but not both.

Some PCI Express graphics cards require more power than the slot is able to provide, and use the 6-pin input connector shown below. This connector must never be confused with 4-pin or 8-pin motherboard power, as its polarity is the opposite of those!

AGP cards that required additional power used a 4-pin connector as described for floppy or Ultra ATA drives.