Abstract: A portable apparatus for applying information in the form of words, numerals and/or other characters to the frames of diapositives has a housing with a pocket which receives a frame to be provided with information. A stop arrests the frame in an optimum position for the application of information by an electronic printer of the type used in pocket-sized or table-model calculators. The printer is connected with a memory which can receive information for transmission to the printer, as well as with a display unit so that the person using the apparatus can observe the information which is about to be applied to a frame in the pocket. An electronically actuated transporting system is provided to introduce frames into, and/or to withdraw frames from, the pocket.