In the olden days, plugging something into your computer—a mouse, a printer, a hard drive—required a zoo of cables. Maybe you needed a PS/2 connector or a serial port, the Apple Desktop

In the end, I think the universality of it is what really took off. That was what we were trying to do.

JP: COMDEX was a huge show in Las Vegas, and [in 1998], we rented a big hall, and we actually had a big showcase as well. We rented a big pavilion where we did a press event, and we attached the full 127 devices to one PC, and we hired Bill Nye The Science Guy to plug in the last one to kind of show how this one port on the PC could support—we had a whole stage full of different printers! We went around and shook a mouse and shook a different mouse—or print something here, and print something there.

Okay, but: why wasn’t the plug reversible?

AB: Good question. We had looked at it, but the whole goal here was to make it very inexpensive, and at that point, we were trying to solve all the USB problems with two wires. At that point, if you added wires to make things flippable, you have to add wires, and you also have to add a lot of silicon. Wires and pins cost real money, so we decided to keep it as cheap as possible. With serial port and parallel port, there were versions that were 25 pins and 36 pins and so on and so forth. The cables were very thick and expensive. We were trying to solve all the problems. We went in favor of fewer wires. In hindsight, a flippable connector would have been better.

AB: Our goal was to say that this interface should be such that it should work on a mouse and it should also work on a high-end printer or on digital cameras. That’s what we were looking at, the range of products. At one end, we wanted it simple enough, so there could be very low costs. At the other end, we wanted to make sure that it could be scaled and, just as we speak today, we’re running the USB at tens of gigs. The original one was running at 12 megs. We’ve come a long way in scaling.

The call from Microsoft’s Betsy Tanner that saved USB

JP: One of the people we met at Microsoft was Betsy Tanner, and at the time, she was the engineering manager for the mouse. I talked to Betsy and said, “if there ever comes a day that you’re not going to use USB for your next Microsoft mouse, I need to know.” And she says, “okay, that’s a fair request.”

We were designing USB—originally, it was supposed to be a five megabit-per-second bus, which at the time was faster than anything else that normally would come at the back of the PC. It’s not fast by today’s standards, but at the time, it seemed fast. And the reason we wanted high speed was so you could fan it out through hubs, and basically, however many devices would be attached to that single port would be sharing that bandwidth—not necessarily all being used simultaneously, but we wanted it to be fairly robust. Well, Betsy called me one day and said, “Jim, you asked me to call you if we’re not going to be using USB for the mouse. I’m calling you to tell you we’re not going to be able to do it because we have a problem.”