Abstract: A data input system of a multi-window mode in which a plurality of logic pictures can be displayed on a physical image screen of a CRT display. An input data once stored in a specified area of a memory is displayed in a selected one of the logical pictures. The system includes at least one logic picture designating device equipped with an indicator lamp, and transfer keys for designating one of the display fields in the logic picture. In accordance with combinations of designation and non-designation of the logic pictures, a data input path of the stored input data to the logic picture in which cursor is present or the logic picture in which cursor is absent is exchangeably selected, whereby the data stored in the specified memory area is transferred for display to the field designated by the transfer key in the selected picture through the input path as established.