Sources have published photographs of the first-generation Apple iPad prototype, which received a mysterious secondary port located on the left side of the device.
Presumably this is the second 30-pin connector. Apple originally planned to use a dual docking system in its first tablet. The second port is on the left side of the device.
Prototype Apple developer Giulio Zompetti said the second port was removed during the development phase of the DVT. The development of Apple hardware innovations usually goes through the stages of EVT (Engineering Verification Test), DVT (Design Verification Test), PVT (Production Verification Test) and other stages.
One of the first-generation Apple iPad prototypes was auctioned off on eBay in 2012.