Recognising the growing need for a fast and versatile machine to handle the output from high-speed data-processing systems, Standard Telecommunication Laboratories, Harlow, Essex, has developed the Ferrodot magnetic printing process. Most of the disadvantages suffered by existing high-speed printers have been eliminated, and, since the processes of character selection and symbol forming are performed by conventional electronic logic circuits, it can be expected that the upper limit of operating speed will advance in step with future progress in electronic logic.