Silicon Chip Magazine ran a competition in 2021 to build a noughts-and-crosses machine based on one that Australian electronics legend Dick Smith built from par

Silicon Chip Magazine ran a competition in 2021 to build a noughts-and-crosses machine based on one that Australian electronics legend Dick Smith built from parts from an electromechanical phone exchange. They ran a series of articles on it, including an electromechanical one of which unfortunately only the first page is available online although it gives you an idea: https://www.siliconchip.com.au/Issue/SC/2024/March/Electromechanical+Tic-Tac-Toe https://www.siliconchip.com.au/Issue/SC/2024/March/Electrome.... If you can find the articles there's a lot of detail in them on how to do it with minimum circuitry. Someone had also done it with relays a few years before Dick Smith, https://www.vintagecomputer.net/cisc367/Radio%20Electronics%20Dec%201956%20Relay%20Moe%20Plays%20Tic-tac-toe.pdf https://www.vintagecomputer.net/cisc367/Radio%20Electronics%.... There's an even earlier one very briefly mentioned in this 1949 newsreel, https://www.youtube.com/watch?v=SlNxBb_27CA https://www.youtube.com/watch?v=SlNxBb_27CA