Method and apparatus for performing true right justification applicable to character printers utilizing variable character spacing. The method of the present invention may be applied to any printer that is capable of variable character pitch settings in response to external control signals. In addition to such a printer, apparatus includes a word processing terminal, and a microcomputer dedicated to the terminal and printer and designed to map the features of the terminal into features available in the printer. In addition to the functions of initialization, data discrimination, control code examination, and vertical carriage positioning, two other functions are provided, one of which does mapping and horizontal carriage positioning, the other of which comprises a service routine used by the other functions to read, write, or store characters and to calculate dimensional values. Horizontal carriage position is controlled so that extra space on a line is distributed by increasing the space between individual characters depending upon the results of calculations determining pairs of pitch values and character quantities for each line of text.