We have developed a digital servo, which self-calibrates offset and gain, for use as a servo for magneto-optical disk drives. This self-calibration scheme was incorporated into the focusing servo and tracking servo. We used the discrete block format for media. Our test using the prototype drive revealed that the manufacturing dispersion of components could be absorbed and that servos showed a sufficiently high stability. Also, we confirmed that the developed digital servo system had comparable compatibility margin for recording and reading to the conventional continuous servo system.