This is the story of how Apple reinvented the phone. The general outlines of this tale have been told before, most thoroughly in Isaacson’s biography. But the Samsung case—which ended last month with a resounding victory for Apple—revealed a trove of details about the invention, the sort of details that Apple is ordinarily loath to make public. We got pictures of dozens of prototypes of the iPhone and iPad. We got internal email that explained how executives and designers solved key problems in the iPhone’s design. We got testimony from Apple’s top brass explaining why the iPhone was a gamble.

Put it all together and you get remarkable story about a device that, under the normal rules of business, should not have been invented. Given the popularity of the iPod and its centrality to Apple’s bottom line, Apple should have been the last company on the planet to try to build something whose explicit purpose was to kill music players. Yet Apple’s inner circle knew that one day, a phone maker would solve the interface problem, creating a universal device that could make calls, play music and videos, and do everything else, too—a device that would eat the iPod’s lunch. Apple’s only chance at staving off that future was to invent the iPod killer itself. More than this simple business calculation, though, Apple’s brass saw the phone as an opportunity for real innovation. “We wanted to build a phone for ourselves,” Scott Forstall, who heads the team that built the phone’s operating system, said at the trial. “We wanted to build a phone that we loved.”

The problem was how to do it. When Jobs unveiled the iPhone in 2007, he showed off a picture of an iPod with a rotary-phone dialer instead of a click wheel. That was a joke, but it wasn’t far from Apple’s initial thoughts about phones. The click wheel—the brilliant interface that powered the iPod (which was invented for Apple by a firm called Synaptics)—was a simple, widely understood way to navigate through menus in order to play music. So why not use it to make calls, too?

In 2005, Tony Fadell, the engineer who’s credited with inventing the first iPod, got hold of a high-end desk phone made by Samsung and Bang & Olufsen that you navigated using a set of numerical keys placed around a rotating wheel. A Samsung cell phone, the X810, used a similar rotating wheel for input. Fadell didn’t seem to like the idea. “Weird way to hold the cellphone,” he wrote in an email to others at Apple. But Jobs thought it could work. “This may be our answer—we could put the number pad around our clickwheel,” he wrote. (Samsung pointed to this thread as evidence for its claim that Apple’s designs were inspired by other companies, including Samsung itself.)

Around the same time, Jonathan Ive, Apple’s chief designer, had been investigating a technology that he thought could do wonderful things someday—a touch display that could understand taps from multiple fingers at once. (Note that Apple did not invent multitouch interfaces; it was one of several companies investigating the technology at the time.) According to Isaacson’s biography, the company’s initial plan was to the use the new touch system to build a tablet computer. Apple’s tablet project began in 2003—seven years before the iPad went on sale—but as it progressed, it dawned on executives that multitouch might work on phones. At one meeting in 2004, Jobs and his team looked a prototype tablet that displayed a list of contacts. “You could tap on the contact and it would slide over and show you the information,” Forstall testified. “It was just amazing.”

Jobs himself was particularly taken by two features that Bas Ording, a talented user-interface designer, had built into the tablet prototype. One was “inertial scrolling”—when you flick at a list of items on the screen, the list moves as a function of how fast you swipe, and then it comes to rest slowly, as if being affected by real-world inertia. Another was the “rubber-band effect,” which causes a list to bounce against the edge of the screen when there were no more items to display. When Jobs saw the prototype, he thought, “My god, we can build a phone out of this,” he told the D Conference in 2010.