Elektor
Published in the 7th issue of Elektor in november 1975 and featured a Tennis game in its simplest form: two paddles and a ball. The design used 13 TTL chips (74xx series) in analog mode. Later in 1976, Elektor published several improvements in issues 11 and 13.
https://www.pong-story.com/pics/mags/elektor1175/Elektor1175.pdf