Abstract: Character data is entered into a cathode ray tube display device from a keyboard or from a tape reader or the like selected by a key on the keyboard. The data is stored in a main memory inside the display device and simultaneously displayed on the cathode ray tube for composing and editing. An auxiliary memory is disposed between the display device and output devices such as tape punches so that data may transferred from the main memory of the display device into the auxiliary memory, and the data may be transferred from the auxiliary memory to the output devices while new data is being entered into the display device. Selected characters on the display, such as capitals, may be emphasized by displaying a dotted or solid line above or below the character or slanting the character. A cursor controlled by the keyboard is displayed on the cathode ray tube to indicate the position for entry or editing of data. Warning means are provide to give an indication when the cursor reaches the end of the display.