Just watched these videos and it’s amazing how these games had like 90 degree turning movements
I agree.
They should be good resources on zooperdan's site although I never really dug into those : https://www.dungeoncrawlers.org/resources/gamedev/.
Heroine's Dusk is one where the sources are open and well documented : https://github.com/clintbellanger/heroine-dusk/tree/master/release.