Casio College fx-80 : which IC hides inside ?

[jebem]

Thank you for the additional information, Marc.
I agree with you that it can be very risky to remove the LCD.

I'm looking now for one of these models in my local auction sites.
Apparently these are kind of rare models when compared with older models like the fx-29 or 39.
I am trying to not order from USA due to customs on top of s&h costs, but I understand that would be much easier to find a good specimen from there.