How to upgrade your fx-82es, fx-83es and fx-85es to a fx991esWatch
1. Check what version you have - on the back, just above the made in China sign, there is a letter in a circle: if it’s a B, unlucky because you can’t do the mod, however if it’s an A you can.
2. Open up your calculator - on the back there are six screws, using a Phillips screw driver, remove these and then lift off the back, revealing the circuit board.
3. Find the P4 jumper - on the circuit board there are six screws, between the middle two is a little white P4, to the right of this is a small split silver circle. Take your graphite pencil and colour this, making sure the whole thing is covered.
4. Put it back together-now put the back, back on and screw the screws into the holes.
This procedure basically makes the calculator confuse itself about which model it is; models only differ at the jumps. Casio did this to make the calculator suitable for all exams, as in China, you can't use an fx-991es in an exam.
I think I kinda like this.
It's a little bit cheating though, as over here 991 are banned in exams too.
Where are you? By the way all but two of the buttons stay exactly the same and the only two that change are X^3 which can be substituted with the X^y button. The other button is Abs which is rather useless.
Leeds Uni. They banned the 991. Well, they have in maths, physics and engineering.
And thanks for posting OP, I was going to buy a FX-991 but I might see if I can find a version A FX-82, 83 or 85 as they're quite a bit cheaper.
I'm guessing the Ti89 is banned also? It's my main calculator and can basically do anything symbolically. I don't see why it's banned, when it just means that you can quickly do simple calculations and integrations, that long hand would take much longer. It's silly really as in the work place,you'd use a calculator.
Basically they've banned everything that isn't on this very short list. They recommend the fx-85.
I guess they banned it because in the right hands it's easy to cheat. You can do more than just the intergration etc with it. You can program lots of formulas, set up tables etc. The 991 is a very powerful tool.
The TI-89 though is a different story. Symbolic algebra and calculus, linear algebra, graphing, custom programs...
aparantly in china some maths teachers told the whole class to modify their calculator to cheat in the exam. so the department of education banned fx-82es's version A in the exam. casio provided free version B replacement for the student who owned version A.
I have a 991 that I use most of the time and an 83-es that I save for exams. My school buys loads of the 83s and sells them to the students for £4.50 because they're an educational institute and don't have to pay tax (or something).
Attached, however, is a picture of all the little bits of paper I stuck on the calculator so that I didn't have to remember all the positions from my 991.
In case you can't read what they are:
(from left to right, beginning from the top)
CALC / SOLVE / =
INTEGRAL / d/dx / :
x^3 / DEC
Nth ROOT / HEX
10^x / BIN
e^x / OCT
arccos / E
arctan / F
left arrow (reverse ENG) / i
Hope it helps.
Out of curiosity... how would you program, say ? Obviously I wouldn't actually use the calculator for that, just wanted an example.