The electronic calculator was made by Yi Man-yeong (1924-2013), former professor of Hanyang University, in 1964 following the two predecessors that he developed in 1962 and 1963 respectively but were lost by fire. The calculator is designed to use an electronic system based on vacuum tubes to calculate high-order differential and integral equations, form input-output terminals that can be practically used for experiments, and output the calculated values in the form of waves on a CRT monitor. The invention was productively used for the education and research of control engineering during the 1960s and 1970s, playing an important role in the development of science and technology in Korea.