A handheld mobile communications device comprising: a support structure; an antenna mounted on the support structure for transmitting and receiving radio signals; radio signal processing circuitry positioned on the support structure to process the radio signals; a speaker and microphone arrangement positioned on the support structure and operatively connected to the radio signal processing circuitry; a printhead positioned on the support structure to carry out a printing operation; a capping mechanism configured to selectively cap the printhead when the printhead is not in use; and printing processing circuitry positioned on the support structure, the printing processing circuitry being configured to: generate dot data; supply the dot data to the printhead; and control operation of the printhead.