Abstract: A display for use in a computer, for example a word processor or a personal computer, includes a device for forming a help message on the display. The help message can provide help when an error occurs in operation. Also a help message can be provided for a current mode when a help key in depressed thus assisting the operators even though there is no error.

Abstract: An enlarged pattern generator generates an enlarged dot matrix pattern from an original dot matrix pattern by providing up to four mutually adjacent dots. Presence and absence of neighboring dots are examined regarding each dot in the original dot matrix pattern in order to determine whether less than four dots should be provided in the enlarged pattern corresponding thereto.

Abstract: A motor speed control system controls the rotation speed of the motor in accordance with the pulse width of a speed control pulse signal applied to the motor speed control system. The speed control pulse signal is not directly applied to the motor, but is converted to a voltage signal having a voltage level which corresponds to the pulse width of the speed control pulse signal. The converting system includes a charge/discharge circuit for varying a charge voltage level of a capacitor in accordance with the differences of the actual rotation speed of the motor and the desired rotation speed of the motor represented by the speed control pulse signal. The charge voltage level stored in the capacitor is applied to the motor to drive it.

Abstract: A character pattern to be recognized is divided into a predetermined number of parallel segments of equal width extending in one direction and character information on respective ones of the segments is read out via a line of photoelectric cells. Two pieces of the character information on two adjacent segments are evaluated together in developing symbolic information indicative of the correlation between two adjacent segment patterns. By the action of simplified feature extraction systems, a plurality of two-dimensional features are established in accordance with all combinations of the symbolic information which have been derived throughout the scanning procedure. The symbolic information is developed particularly with regard to the number of loops within the character pattern, the shape of the left edge portion, the shape of the right edge portion, the shape of the upper edge portion and the shape of the lower edge portion of the character pattern.