Post Reply 
Casio College fx-80 : which IC hides inside ?
06-02-2016, 05:11 PM (This post was last modified: 06-02-2016 05:11 PM by Mark.)
Post: #5
RE: Casio College fx-80 : which IC hides inside ?
Thanks, Damaltor :-) but... I already saw that, ironically, the result (8.99116141) is shared by 2 different processors : The Hitachi HD36130 and the -probably twins- NEC D1897/1898G !
Maybe we've got here the same CPU core+firmware made by 2 of the major Japanese chipmakers. I remember having seen 2 other ones (again one from Hitachi, the other one from NEC) with the very same instruction set -and again in Casio machines.

These chipmakers later merged with a 3rd one (Mitsubishi) to become Renesas. The connections between them seem to have old roots. It also tells us that these calculators were sold in such quantities that a second source was needed to follow the market : production yields weren't as high in the seventies.

Honestly, it's not a fundamental question, just curiosity for fun. Anyway, the historical scope keeps its mysteries, even if many are unveiled by studying the patents : many companies didn't care about keeping accurate records of their activities, 30-40 years ago the calculator market evolved at a break-neck pace. But it already acted like the software industry : chip architectures had a surprisingly long lifetime... our beloved hp's are there to illustrate that.

In a few words : I simply have liked to know if someone had actually dismantled his/her fx-80 in order to answer the question :-)
Find all posts by this user
Quote this message in a reply
Post Reply 

Messages In This Thread
RE: Casio College fx-80 : which IC hides inside ? - Mark - 06-02-2016 05:11 PM

User(s) browsing this thread: 1 Guest(s)