A toy robot system includes a toy robot and a surface over which the robot can
move. The surface is constructed from a number of modules of various types that
may be joined together. Each module (except for spacer modules) includes at least
one track segment along which the robot may move. Each module is square and each
track segment extends from the center of the module to one side. A code readable
by the robot is provided at the beginning of each segment so that the robot knows
what type of module it is entering, and a code is provided at the center of each
module so that the robot can calculate its position.
