'Not' in-game menu is double the direction you don't want. Enter>two quick pushes.
Yeah, but you have to have something else mapped first, as mame doesn't allow a map of just a not: "not joy1 b1" is not valid, but "joy1 up not joy1 b1" is valid. So you have to push the non-not key/button(s) before you do a the double push. And mame has to have at least one non-not mapped
before the double pushes work. Examples: "enter, A, A" doesn't register; "enter, A, A, W" registers as "A W" (both A and W need to pressed at the same time); "enter, A, A, W, W" doesn't work; and "enter, A, A, W, W, E" registers as "A NOT W E", which is the same as "A E NOT W" (both A & E keys have to be pushed, but the W key).
(If you understood all that, I'm sorry; I've been a bad influence.

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