Last week we shared a look at the click wheel-inspired iPhone interface that ended up being scrapped in favor of iOS. Now, Sonny Dickson has shared a video and gallery of images comparing two early prototypes of the iPhone: Tony Fadell’s P1 project and Scott Forstall’s P2.

The P1 is the click-wheel interface that we shared last week, with the touch input method being applied to the iconic scroll wheel. The P2, on the other hand, is the basis of what we have today, using individual icons to depict specific functions of the device.

Throughout the process, both projects ran on Acorn OS with the same hardware, with Apple testing countless different variations. Additionally, both the P1 and P2 teams were very competitive throughout the development of the iPhone, as they needed to impress Steve Jobs.

Given we’re just a day after the 10th anniversary of the first-gen iPhone, it’s interesting to look back at what could have been and to see the prototypes Apple was testing Check out the full comparison video between the P1 and P2 below and view a gallery of images here.

Contrary to the P1 interface, the P2 OS used individual icons to interact with the phone rather than a scroll wheel. It was the first true touch and app driven phone experience.

When the iPhone was undergoing development, both projects ran what is known as Acorn OS and ran on the same hardware. Both teams were extremely competitive because both project teams wanted to impress Steve Jobs