Abstract: Additional attachment for key operated machines comprises a frame which covers the keyboard and which holds the desired entire number of symbols. The frame has the shape of a perforated plate which is fixed to the keyboard. Additional keys are located in the perforations of the plate and are in alignment with the keys of the key operated machine. The cover plate is placed in a detachable manner on the surface of the perforated plate. The cover plate is perforated in agreement with the perforations of the first plate and is equipped with the desired symbols.