I think i found a secret mode on the casio fx-82MS. It allows you to have calculation history and a few more stuff.
1- press shift + clr
2- press 3
3- VERY quickly press = and on
4- if you dont do it fast enough it wont work, and you might have to do it multiple times
if it works, the screen will be dim and instead of a "0." appearing, a "0," will appear
is this something special or?