Building a simulator for a robot with many degrees of freedom and various sensors, such as Sony’s AIBO4, is a daunting task. Our implementation does not simulate raw sensor values or actuator commands, rather we model an intermediate software layer which passes processed sensor data to the controller and receives high-level control commands. This allows us to construct a simulator that runs at over 11000 times faster than real time. Using our simulator we evolve a ball-chasing behavior that successfully transfers to an actual AIBO.