The first home game to feature a password system was 1983’s Survival Island for the Atari 2600. Password-backed games began appearing a little more than a year into the NESs North American lifetime. Nintendo itself was promoting a line of Password Pak-branded games at CES in the summer of that year. Passwords opened up a new level of possibilities for gaming, but they were still limited before becoming unreasonably long and even short of writing down passwords on slips of paper.”]
Source: https://tedium.co/2019/02/21/video-game-save-state-history/