The MIT AI Lab’s second mobile robot, MOBOT-2, has a number of unique design features. In this paper we describe two of them in detail. First, MOBOT-2 has an extremely cheap 32 processor distributed control system. The processor system, called BARNACLE, runs asynchronously with no central locus of control. Unlike almost all other parallel processors this one has no expensive communications routing network. The communication topology is determined by a distributed patch panel. All computing is done onboard the robot. Second, MOBOT-2 has an onboard arm. It is lightweight, but has an extremely large working volume. The arm is controlled by the parallel processor.