Abstract: A process for controlling line spacing, including the steps of clearing or setting line pitch variable mode in a first state; checking keyboard input in a second stage; determining whether the keyboard input indicates line pitch variable mode, and performing a function corresponding to keyboard input in a third stage if the keyboard input does not indicate line pitch variable mode; setting the length specified in a fourth stage if the keyboard indicates a specified length of line spacing; in a fifth stage, if the keyboard does not indicate a specified length in the fourth stage, returning the carriage through feeding by the length of the variable line pitch and returning to the first stage when the keyboard input in the fifth stage does not indicate a return function, line feeding by the length of the variable line pitch and returning to the first stage when the keyboard input indicates an index key; in a seventh stage, if the keyboard input in the sixth stage does not indicate an index key, performing a reve