A developing cartridge may include a housing configured to hold toner. The mixer drive shaft is guided in a laterally displaceable manner such that the driver of the mixer drive shaft is situated on the center axis of the mixer rotor independently of the cross-sectional ratio of the containers of the double cartridge. The switch device establishes an inter-station key for the two stations which are connected to the switch device directly, by which the embodiments of the present invention ensure the confidentiality and integrality of user data between the stations. The IP address of the user’s current location is used in concert with the terminal’s identifier, which is itself an IP address, to route incoming computing communications connection requests to the current location of the user.