To explore the capabilities of the VEX Robotics System, we chose to build our simplified version of iRobot's PackBot (see ). The goal was for the robot to be able to climb stairs and small piles of debris using only VEX components. Sounds like a tall order, right? You bet. Fortunately, our friends at Radio Shack were kind enough to allow us to preview some of the exciting accessories planned for the VEX system, including tank treads, a programming kit, ultrasonic rangefinder sensors, and optical shaft encoders. ROBOT magazine provided us with a wireless remote camera distributed by Shulman Aviation to complete our PackBot's control package.