6 of 7: Frank Lee, second face on left, a Drexel University game-design professor, watches Sydney Nixon, right, and Lydia Solomon, center, plat the classic Atari video game Pong displayed on the facade of the Cira Center in Philadelphia on Friday April 19, 2013. Hundreds of built-in LED lights embedded in the north face of the Cira Centre were used to replicate the familiar paddles and ball with gamers controlling giant, table-mounted joysticks across the Schuylkill River from the building. (AP Photo/ Joseph Kaczmarek) ( Photo)

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