USB's 'Biggest Annoyance Is Reversibility', And It's Meant To Be That Way

Ajay Bhatt
Chief Client Platform Architect at Intel

In the modern days of computing, people have been accustomed to plugging in a mouse, a smartphone, or a thumb drive using a USB. Despite being a universal plug, plugging in the plug requires efforts.

In most cases, users of USB would get it wrong in the first time, and need to flip the plug around to make it slide in. In other cases, it can also be maddening difficulty to plug it in correctly, despite having it positioned in the correct orientation.

This is a shared experience. Some people call this the 'USB Paradox', the seemingly impossible process of making a 50-50 guess wrong twice.

For users, it seems like the design of USB is flawed. By making it reversible, the process of sticking something through a USB slot should be a breeze. But according to its inventor, it's meant to be that way.

Ajay Bhatt was the leader behind the Intel team that gave the world the USB in the mid-'90s. The Indian-born American was the architect who helped defined and developed the widely used technology, as well as AGP (Accelerated Graphics Port), PCI Express, Platform Power management architecture and various chipset improvements.

"The biggest annoyance is reversibility," Bhatt acknowledges.

But he also said that designing USBs to be reversible would have doubled the cost of the technology, requiring double the wires and double the circuits. This is why USBs were designed to be irreversible on purpose.

Ajay Bhatt
Ajay Bhatt was the leader behind the Intel team that gave the world the USB in the mid-'90s

USB is short for 'Universal Serial Bus', a near-ubiquitous connection interface that allows users to plug devices into a computer.

Bhatt's idea for the USB was inspired by his own experience as a user dealing with frustrations of tumbleweed of tangled wires, with each requiring different type of port. He wants USB to be the connector to rule them all, and also a product that bypasses the needs for separate floppy disk or driver to install each application.

"Both as a user and a developer, I saw that at that time, available interfaces were complex and very user unfriendly," Bhatt said, believing that people should be able to enjoy computers without such hassles.

But companies had an inherent fear of breaking the existing compatibility functions.

Bhatt initially pitched the idea to other tech companies, including Apple and Microsoft. But there, he received a lukewarm response, and only Intel - the company he was working for at the time - was bold enough to make the investment in his idea.

The team at Intel which was led by Bhatt, anticipated the user frustration. They had the idea of making a round connector which has less room for error, but opted for a rectangular design with a 50-50 change to plug it in correctly.

"In hindsight, based on all the experiences that we all had, of course it was not as easy as it should be," Bhatt said.

Ajay Bhatt - USB
At the time of its invention, USB was meant to be the connector to rule all connectors

When trying to persuade all major computer companies to adopt the seemingly flawed USB model, "It took us some time to prove that this technology is indispensable," Bhatt said.

USB is designed to grip the plug to its port with the force from the receptacle, with no screws, clips, or thumb-turns used by some older connectors.

And one of the things that made the design acceptable, was because it was cheap.

Despite owning hundreds of patents, Bhatt has not made any money from his USB designs. This is simply because Intel owns all the patents, and decided to make it open and royalty free from the beginning

"I don’t do these things for money. I did this to bring about change, and it’s not very often that somebody gets a chance to bring about this big a change," said Bhatt. "We were not worried about notoriety. In the end, it's a team sport - my feeling is that if everyone adopts your idea, then you've succeeded. Notoriety should be given to the technology."

"As an engineer, I’ve been handsomely rewarded by the company,” Bhatt added. “And I couldn’t do this kind of work anywhere else. I have nothing to complain.”

As technology progressed, different types of USB designs were created. Some were invented to prevent users in accidentally connecting two power sources, for example. But the design was then ditched with the advent of multi-purpose USB connections (such as USB On-The-Go in smartphones, and USB-powered Wi-Fi routers), which require A-to-A, B-to-B, and sometimes Y/splitter cables.

This eventually gave birth to USB-C plug, which is reversible.