Great demo but can you confirm that the music is real and not added to the video ? Funny to see that this calculator runs way faster than my good old Atari STe (tho there's more than that to be taken into account) !

The audio comes from a mobile phone. The calculator has no audio hardware on board.

@tomae : thanks for additional info ! I was really wondering whether calculators had gone so powerful as to emulate a full ATARI ST :)