6 replies to this topic

[LtIvan]

I have two calculators, a CASIO fx-82AU PLUS II and a SHARP EL-531WH, (which one do I preffer? the Casio, although the Sharp does have Binary, Hex, etc and Boolean operators).

 

FIRST

For both I notice when you save data in statistic mode and then turn the power off and then back on again, it still tores the memory, this was not a surprising fact.

 

I was just wondering what type of memory the Casio (maybe the Sharp if someone else knows) has to store memory when turned off.

What I trying to say is the memory volatile or not? Does in use flash memory? a form of RAM or a ROM?

 

I also then pull the casing apart to see what type, all I noticed was the big black thing in the centre which I presumed was the IC?

 

SECOND

Also if you don't know about the Easter egg on most Casio calculators when you hold down Shift and 7 and press ON, then press 9 then Shift several times to get to Contrast then the button function check.

 

When it goes on

LY711X VerA 

SUM OA69 OK

Pd- Read OK 

Press AC

 

What does it mean?

[LtIvan]

These sites helped:

http://educationfore...ator-works.html

http://www.engineers...rticles/cob-ics

 

Now I know it's called a COB IC, but does it store the memory and how?

 

Please reply.

[Viliami]

COB IC can't store any more memory, the can only be programmed once and then they are ROM.

I don't know what type of RAM the fx-82AU plus has but you can test if the RAM is volatile or not by unscrewing the calculator and taking the batteries out.

Wait for at least 15 minutes then put them back in, if all your memory is gone, than the RAM is volatile.

 

If all your memory is gone, then that means that the calculator stores all of the memory in the RAM and even when you turn it off it is still powering the RAM.

 

If your memory is not gone, then I don't really know, the RAM is most likely still volatile but it doesn't need to powered when off.

I think it might have some sort of memory (maybe flash?) on the calc to store all the settings, contrast, math history, etc..

When you turn off the calculator it copies the RAM memory to the actual memory, during this process it usually shows a picture of the CASIO logo, and then powers off for real. No RAM needs to be powered anymore. Then, when you power it back on, the memory is copied back onto the RAM and then it comes up with the previous state you were in when you turned the calculator off.

If your calculator shows the casio logo when powering off, then it's more likely that it has some kind of long term memory.

[kasio]

The Casio FX-82AU should have EEPROM however some models appear to have a form of SRAM instead, your milleage may vary. If the memory is kept after the method you said, its EEPROM. My FX-82ES and FX-82GT Plus both keep it forever. I have hacked the EEPROM on my FX-82ES with a software bug

Edited by kaikun97, 25 January 2016 - 09:49 PM.

[EnderFire09]

Although not much is known about the memory type, there are some cool hacks for the fx-82AU PLUS II

 

First note that all of the hacks only work on the LY711X VerA with the checksum of 0A69. You can check in diagnostics mode. To enter diagnostic mode, just look it up, there are plenty of tutorials on how to use diagnostic mode, out there.


If the calculator freezes/crashes, press [ON].

Firstly, all of the hacks use REG hackstrings, hackstrings that involve the small 'A', the small 'B' and 'r' and there are two types of REG hackstrings, ones that involve STAT Submode 0 and ones that involve the MathIO overflow (divide bracket) bug.


Firstly to get into STAT submode 0 you press [MODE], 2, then you press AC/on then [ON] around 0.5 seconds after pressing AC/on. Note that this may be hard for the first few times you try, but you will get better the more you do it.
If you are successful, you should see that the STAT indicator is on and REG is available in the STAT menu Shift, 1. If you are not the go back into COMP mode and try again.


In the REG Menu Shift, 1, 5, you will see 5 characters. We are interested in 2 of them, 'r' and the small 'A'


To get 'r', press Shift, 1, 5, 3.

To get the small 'A', press Shift, 1, 5, 1


sqrt - square root symbol


STAT submode 0 REG hackstrings


1. small 'A' by it self - Enters Mode 68

2. 1(1(1(1r - Enters Mode 68 with MathIO

3. A(BCr - Puts the input into table input mode and corrupts the ram, causing the hackstrings to have different results until you press [ON].

4. 1sqrt(1sqrt(1sqrt(1sqrt(1sqrt(1sqrt(1r - teleport cursor far to the right, past the start of the cache, causing basic overflow.



Now for the MathIO hacks


To get 'r' in MathIO you must type Pol(0,1) then press [=], then press ÷, 9, and then press [LEFT BRACKET] until you cant type any more left brackets. Then press [=], then AC/on, ▲, AC/on, [BACK].

Now your should have 'r' and a bunch of other characters next to it. Delete everything except for 'r'


Now for the COMP, MathIO hacks:


1. (7979(7979(7979(7979r - Enters Vector mode, which is not supported by the fx-82AU PLUS II

2. A(BCr->M v/[] (Square root) - Enters Mode 68 with LineIO without crashing the calculator, Press AC/on, then [BACK], delete every thing except for the box. Now move the cursor to the left of the box, then press [RIGHT] once. Initially, you cant see what you are typing until you have typed about a dozen characters. You have now achieved basic overflow.



Terms


1. Mode 68 - see http://casiocalc.wikidot.com/mode-68

2. Basic overflow - see http://casiocalc.wik.../basic-overflow



For more information please visit http://casiocalc.wikidot.com/ and https://community.ca...s-plus-hacking/

[CalcLoverHK]

@EnderFire09
Um, this thread was made years ago and all people here are unlikely to come back to UCF to post or unable to receive message from you. And also just put link of your topic here and not the whole content (this is some kind of spam IMO).

[siealex]

1. (7979(7979(7979(7979r - Enters Vector mode, which is not supported by the fx-82AU PLUS II

Does this mode actually work?