Apple had developed the iPhone in secret over those two and a half years, and for many inside the company, the device had only been known by the codenames “M68” and “Purple 2.” Apple was focused on surprising everyone with the iPhone, and that meant that many of the engineers working on the original handset didn’t even know what it would eventually look like.
To achieve that level of secrecy, Apple created special prototype development boards that contained nearly all of the iPhone’s parts, spread out across a large circuit board. The Verge has obtained exclusive access to the original iPhone M68 prototype board from 2006 / 2007, thanks to Red M Sixty, a source that asked to remain anonymous. It’s the first time this board has been pictured publicly, and it provides a rare historical look at an important part of computing history, showing how Apple developed the original iPhone. Link