1. A foldable alpha numeric keyboard device configured to input data items into a computer or similar processing device, said keyboard device comprising a first electrically conductive fabric sheet and a second electrically conductive fabric sheet; an interface circuit configured to supply voltages to and receive outputs from said keyboard; wherein said keyboard is configured to produce an output in response to a mechanical interaction and said interface circuit is arranged to respond to said mechanical interaction and to provide a data item to said computer or similar processing device.