This side up — Finally

Submitted by gwolf on Sat, 11/20/2010 - 23:38

Can I count myself in a majority of people that feel that, while the USB standard is a great advance regarding the way we used to connect our stuff to the computer some years ago (when we used a different cable for every friggin' device we had, and we had to care about having only one parallel and two seral ports in regular configurations, and don't even get me started on port settings — speed, parity, etc.), every time we hold a USB cable in our hand we feel one of the designer teams decided to play a prank on humanity by making the connector's orientation basically unguessable?

By the frustration this square thingy inflinges on us (being any other decent cable used on a computer either have a visually recognizable shape or just round and thus omnidirectional) I think that the rate by which I get the connector with the correct side up (or front, or right, or whatever) is way lower than 50%.

Anyway, I found that the standard does provide for a (IMO quite dubious but still better than guesswork at the port) way to distinguish which way up - Quoting from Wikipedia's entry on USB connectors:

(…)The side of the connector on a USB cable or other product with the "USB Icon" (trident logo) should be "visible" to the user during the mating process.(…)

Officially, the USB 2.0 specification states that the required USB Icon is to be "embossed" ("engraved" on the accompanying diagram) on the "topside" of the USB plug, which "provides easy user recognition and facilitates alignment during the mating process."

There are several caveats which make this less than ideal, some of which you already thought of, some others are in the referred article and I won't reproduce them. I am just amazed that... USB has been around for almost 15 years (and has been the most popular connection type for ~10 years). And I have never seen anybody apparently knowing this rule.

This was a public service announcement in the hopes you will be happier people armed with its knowledge.

markuz's picture

My way to find the right way.

On the connector type "A", I'm used to look for the empty squares, when I find them i know the side up. Another way to know it is by looking at the port and look where the piece of plastic is.

Anonymous's picture

Seeing which side has the

Seeing which side has the logo (I've always known about it, by the way) still is not enough since in many cases the ports are oriented vertically, in which case should the logo go to the left or to the right?

gwolf's picture

The rule still applies

The rule says the connector's logo should be facing the user – So, I'll have to check at my office tomorrow: My computer has two vertical USB connectors. If the computer is supposed to sit at my right, the logo should be facing left. If it is supposed to sit at my left, the logo should be facing right. And I should be fined for breaching the standards, as I find it better to have the box at my right.

Oh, and at home, I have an aging iMac G5. The ports are... At the back. So, am I supposed just not to use them?

ulrik's picture

Apple's cables

Apple's cables used to all follow that rule, including matching the symbol on the cable to the symbol on the box. So for the decendants of Apple ought to have guesses this long ago -- if anyone did survive the old gray macintosh era.

Marcos Dione's picture

Not only that...

... as you show in the only image of the post, there are different connectors, forcing us to actually have one cable per peripheral, even when we don't want them connected all the time. Right now I have an external disk with the squarish (M) connector in the middle of that image, a smartphone with the smallest (XS) to the left and a GPS with the second from the left (S) 1. And of course there are two more types of connectors than the ones you show there. Even more, as the wikipedia page mentions, some companies are using the USB cabling/signal standard, but uses their own connector shapes! So, here again applies the phrase «the goo thing about standards is that you can define your own».

Also, the 'usb logo engraved' rule is not followed by most of the USB thingies (pendrives, etc) manufacturers, so you still have to guess/doublecheck. I have a wireless mouse transceiver that's so small that it can't even fit the logo.

  • 1. These aren't the official names for this ports, buy they could have been.
gregoa's picture


heh :)

same here. each time I touch a USB cable I swear at whoever decided to design them in this way.

Marius Gedminas's picture

I cannot claim to have known

I cannot claim to have known this rule, but I've noticed that the embossed USB logo is on top when I plug the micro-USB cable into my N900, and that saved me from having to try twice every damn time.

Ryukage's picture

Too bad no one follows the rules

I was aware of this rule, however, the rule is useless because the manufacturers don't follow it. Most USB cables have the icon on the correct side, however some OEMs, most notably Dell, have a habit of mounting the ports upside-down. My Memorex TravelDrive doesn't even have a USB trident icon on it, though it's clear which side is "up" (however, I have to turn it upside down to plug into a Dell computer). A Dell pen drive I have goes right-way-up into Dell's upside-down ports, but has to be plugged in upside-down on most other brands of computer.

There's also a rule in the USB spec that limits how large the USB connector can be, so that it doesn't block adjacent ports. Unfortunately, manufacturers seem to have no regard for that rule, either. Most WiFi dongles and SD card adapters completely disregard it, as does that Dell pen drive I mentioned.