superscope introduced some errors here:

Code:
src/mess/drivers/snes.c: In function UINT32 snes_superscope_offscreen_input(const input_field_config*, void*):
src/mess/drivers/snes.c:127: warning: comparison is always false due to limited range of data type
src/mess/drivers/snes.c:127: warning: comparison is always false due to limited range of data type