Abstract: In a word processor a string of characters entered serially via a keyboard into a plurality of positions are centered about a particular point on a line of a record medium by providing a storage medium having a plurality of addressed cells which are serially assigned to the positions on the line of the record medium, the cell addresses ranging between first and second values. The cell assigned to the position which includes the particular point receives the first character of the string while all subsequent data characters are considered as pairs of data characters.