A printer is provided having a print cartridge which includes at least one reservoir for storing printing fluid, a printhead in communication with the reservoirs and a refill port arranged to mate with a corresponding connector of a refill cartridge, a cradle for removably receiving the print cartridge which includes a controller for controlling the printer, and a connection interface for connecting the print cartridge to the controller. The refill port includes inlets corresponding to, and in fluid communication with, each of the reservoirs. The connection interface is configured to receive control signals from the controller for causing, when the refill port is mated with the refill cartridge, refilling of the reservoir, and when the refill port is not mated with the refill cartridge, the printhead to print the printing fluid.