XDA Developers on MSN

Someone discovered the reason why controllers use "A, B, X, Y" buttons, and it was answered 32 years ago

A/B marked primary buttons, X/Y marked secondary buttons. A 1993 Nintendo Power Q&A confirmed the CAD origin of the ABXY labeling. Nintendo kept ABXY; Microsoft swapped A/B positions — switching from ...

The Controller Button Layout Mystery That Nintendo Power Magazine Solved Back In 1993

With the exception of Sony controllers, most other gaming controllers use the A, B, X, Y layout, and for the most part gamers ...