Mystery of the Wii U GamePad port

Nintendo Wii U GamePad - White (Renewed)

White | Wii U Gamepad Dust cover

The Wii U was Supposed to Support two Gamepads, but Nintendo diverted

I've compared the prototype E3 gamepad against the retail version. Nintendo did make some changes after the E3 in 2011 when they exhibited the console. : r/wiiu

What Happened to the Wii U GamePad's Potential? - Editorial - Nintendo World Report

Nintendo at E3: Wii U, Pro Controller, 'Miiverse' online services, and new games - The Verge

Meet The Wii U Gamepad, Nintendo's Answer To Gaming On The iPad

Wii U GamePad: 5 ways we'd fix the Nintendo controller

The surprising (mundane) tech behind the Wii U's magical GamePad

Trash to Treasure - Wii U gamepad with elite mod