fx-9750GIII Storage Memory Crash
Posté le 26/10/2020 10:10
Updated in 2023-12-7 UTC+8
Introduction
In August 2020, I encountered the problem on my fx-9750GIII where I couldn't use my storage memory. Later, I found that a file with impossible name "僂ASSE.g1m" appeared in my calculator stoarge and couldn't delete it in any available ways. After investigation it's confirmed that this file was originally "-CASSE.g1m" from Calcraft. The reason of having a Chinese character is that the hex code of "僂" is the combination of the hex codes of "-" and "C".
Affected models
Possibly all USB Power Graphic 3 models
- fx-9750GIII: CalcLoverHK,
PhantomOverrideAlpha,
laomo,
0070,
zhuchaokn
- fx-9860GIII:
yukki410
- Graph 35+E II:
yet to be seen
Characteristics
- Unable to modify the storage memory (even "Initialize All" won't work)
- LINK app shows error "Data conversion failed."
- Windows reports error 0X8007045D (I/O device error) when attempting to modify the storage content
- (Uncertain, happened once) A file with impossible name (e.g. 僂ASSE.g1m)
Possible procedures
1. Install
C.Basic for FX (important as while it's possibly the main cause, it's also used to execute the workaround syscall below)
2. Create a new program file in
SMEM mode and save it without typing anything, then re-open the file
OR open an existing file in
SMEM mode
3. Type something randomly and delete what you've exactly typed (even typing and then deleting a single letter works, just make sure the final modified file is exactly the same as the original one)
4. Save the file by pressing [EXIT]
5. The moment when you get a "Can't delete file" error pop-up with error code -6 is where this bug is triggered
At first it seems like nothing happened after the error, but as the time passes under normal use, C.Basic starts to pop up the same error more frequently and eventually even a modified program with a single letter added can't be saved.
Reasons
Deducing from the error description ("Can't delete file"), it appears that C.Basic saves a file by deleting the original file first and creating another one with exactly the same content as the modified one. If there is no actual change in the latter one however, C.Basic may confuse between both files and thus being unable to delete the proper file, while forgetting to change the Bfile status from "file opened" state to "ready" state.
However, such problem also appears in other users' GIII calculators without C.Basic, and the reasons for them are unclear.
Workaround
Warning! This method can only be used on the USB Power Graphic 3 models!
Kudos to yukki410 for discovering this method!

Execute Syscall(0x205) in C.Basic and restart the calculator.
Edit (2023-12-7):
I did more tests on this bug after Sentaro21's return on C.Basic development. Unfortunately, the SMEM on my fx-9750GIII is now permanently unusable without C.Basic after initializaing. Somehow it successfully deleted the whole memory while keeping the SMEM in the locked state. Nevertheless, it confirmed a few things.
> This bug can happen even under C.Basic's default settings.
> You may notice a significantly slower speed of saving program while repeating the procedures.
> Suprisingly Syscall(0x205) becomes one of the main causes of this bug. If you manage to trigger the bug using the workaround/still fail to access SMEM after doing it, DO NOT initialize the whole calculator and keep it as is. C.Basic is probably your last resort to dodge this problem.
If you have any other method to solve this problem, feel free to post it here! Thanks for your help and also @Lephenixnoir @Yatis for helping me tackle the problem ever since the encounter of this bug
Citer : Posté le 29/07/2025 21:57 | #
Yes! I've confirmed that the filesystem setup function is something normally called when the OS boots. Yatis and I reverse-engineered that part. I'm back to working on the rescue program. More news tomorrow.
Citer : Posté le 31/07/2025 13:34 | #
The setup crashed but I've been reverse-engineering more and I'm converging towards a brutal but surely effective solution. Still on it...
Citer : Posté le 01/08/2025 17:48 | #
This has been going on for way too long. Summary of the people affected so far
@CalcLoverHK @Mexischillax @Valou94
Does the OS update option of the SYSTEM menu work? You can try to connect it to the PC and start any of the update programs. If you have the latest OS it will tell you that. You don't have to do an actual update, I just want to know if the communications work or not.
Citer : Posté le 01/08/2025 18:15 | #
I just succeeded in using the low-level format function from the OS update option in the SYSTEM menu. That was on OS 3.40, but there's every reason to believe it will also work on 3.70.
We might have a solution to this problem on our hands (finally).
Citer : Posté le 01/08/2025 18:36 | #
It also worked on 3.70. I hope you have the SYSTEM thing. *-*
Citer : Posté le 01/08/2025 21:57 | #
Hello merci beaucoup de m'avoir tagué, je rentre demain de vacance, je t'informerai si jamais cela fonctionne, encore merci !
Citer : Posté le 02/08/2025 16:46 | #
CalcLoverHK reports:
> Hm
> Instant restart after pressing [F3] on both black and white fx-9750GIII
> @Lephenixnoir Nothing changes
Sigh, I'm hoping it'll at least work for someone. x) I'm grasping at straws, ngl.
I still have some faraway leads, at least...
Citer : Posté le 14/08/2025 08:12 | #
I'm here sorry... Having school exams lately.
What is the OS update option of SYSTEM menu? how should I test it?
Sorry again, it's been a really long time and I cant remember...
When I plug in the calculator and press F1 [USB Flash], it comes up with "Preparing USB DO NOT Disconnect" for a few seconds then it shows "Data Conversion Failed".
Citer : Posté le 14/08/2025 08:16 | #
I can't modify any existing files on my calculator, it just says the function failed... (same as 2 years ago)
Citer : Posté le 14/08/2025 10:28 | # |
Fichier joint
Good luck with your exams!
If you go to the SYSTEM menu, and then press F6 followed by F5, you get to the official OS update mechanism. Compared to using OS ERROR mode, this one is better because in OS ERROR mode the filesystem is not mounted/prepared. You can test if it works by starting an OS update, plugging into the computer, then launching any official updater (like version 3.60, just to name one randomly). If you already have a more recent version (or even the latest) the update will fail with an error message "You already have the latest version". If you can get to that message it means the OS update feature will work as expected.
I realize I never attached the program that I sent CalcLoverHK over chat, oops. Here's how to use it:
1. You need to have version 3.40 or 3.70. If you don't have it and you can upgrade to 3.70, that would be easiest for me. Otherwise I need to do more reverse-engineering.
2. Go into SYSTEM mode, F6, F5 (OS update) and plug the calculator into the PC.
3. Run the g3_reset_windows.exe file from the Windows command-line.
You should get a menu with a few options. The only one that matters is "Low-level reset" (I think F3).
4. Press F3 and hope that you get a progress bar for maybe 10-15 seconds, then back to the menu. If that happens press F6 twice to reboot.
If, like CalcLoverHK, you get a crash instantly when pressing F3, that means low-level format couldn't run, and I need to figure out why and keep debugging.