The history of UI/UX is always a fascinating read. Even as I speak japanese, I had never thought that « x » and « o » were batsu (cancel) and maru (validate) – and that the « x » metaphor was also shown on Playstation controllers.
The search for the origins of the « x » go back to Atari TOS, but I think the author should have been looking for text-based graphical interfaces that were being used in DOS and other non-graphical OS at the time.
Awesome little piece anyway.
Update: apparently, the « X » sign in Windows was not used to close the window, but to open a menu…
@soufron L’auteur se trompe à propos de Windows : le bouton de gauche ne fermait pas mais ouvrait un menu. On double-cliquait pour fermer.
— Rubin Sfadj (@rubin) August 13, 2014
Re-update: There is more to the batsu/maru story. In Japan, O is yes, and X is no. But it was reverted in occident to take into account the idea that western people cross checkboxes when they validate something.