A system can include a first housing that includes a processor and memory accessible to the processor; a second housing that includes a display operatively coupled to the processor; a hinge assembly that rotatably couples the first housing and the second housing, where the hinge assembly includes permanent magnets that generate a first magnetic field and a second magnetic field orientable with respect to each other via rotation of the second housing with respect to the first housing, where the first magnetic field and the second magnetic field include an aligned orientation, generate a clockwise restoring torque responsive to rotation in a first rotational direction from the aligned orientation, and generate a counterclockwise restoring torque responsive to rotation in a second, opposite rotational direction from the aligned orientation.