Mappings before version 1.5

USB Button   SNES button   NES button
--------------------------------------
0            B
1            Y
2            SELECT
3            START
4            A             START
5            X             SELECT
6            L             A
7            R             B

Mappings since version 1.5

USB Button   SNES button   NES button
--------------------------------------
0            B             B
1            Y
2            SELECT        SELECT
3            START         START
4            A             A
5            X
6            L
7            R