A data processing system with memory access comprising an operating system for supporting processes, such that the process are associated with one or more resources and the operating system being arranged to police the accessing by processes of resources so as to inhibit a process from accessing resources with which it is not associated. First and second powered wheelsuspension assemblies are connected to the main frame near respective first and second ends of the main frame. A disposal line is fluidly connected to the canister and includes a second valve that is positionable between an open position and a closed position.