A display device is described that comprises an electronic paper display but that does not include a power source that is capable of providing sufficient power to update the electronic paper display. Instead, the electronic paper display can only be updated when receiving external power via a digital data and power bus. The bus also provides pixel data for content to be displayed on the electronic paper display and at least one externally generated bias voltage level for the electronic paper display. The display device further comprises a processor that configured to drive the electronic paper display.