Abstract: When a character key is operated, the apparatus reads display character size data for the inputted character, which corresponds to a selected print character size, in S40. Display dot pattern data corresponding to the starting character code in a text memory is then read out. The thus read out data is stored in the location designated by a display position pointer value of a display data buffer in S42. The print fullwidth data for the inputted character code is then read out in S43 so as to calculate the display fullwidth data for display in S44. The display fullwidth data is added to the display position pointer value to determine the next display position pointer value in S45. The display dot pattern data corresponding to the next character code is placed into the location designated by the next display position pointer value in S42.