Hi, I own both a UK Casio fx-CG100, and a French Casio Graph Math+

Something curious I've realised is that, despite using the same OS updater exe, they still have small regional differences such as:
- Format button behaviour being completely different on the GM+
- The CG100 lets you enable exam mode for the UK, IB, Portugal, and Texas, while the GM+ only lets you select French exam mode
- The GM+ has a red LED by the 2.5mm port which flashes red during exam mode, while the CG100 doesn't (the traces are there on the motherboard, but the LED is completely missing)
- The CG100 has an option in the System Manager to change the Country of the calculator, letting you select between International, Portugal, UK, and US, while this setting is completely missing on the GM+
- Both calculators allow you to change the language of the OS, with the options being the same

Investigating further, I decided to dig into the updater exe a little bit to try and figure out more about the firmware. After a bit of digging, I did manage to extract an 11.9MB binary, which I presume to be the firmware, and a 67.5kB binary, which I presume to be the bootloader. Running the firmware through the strings utility on Linux, I eventually found a section of the firmware with every dialogue for the English language (I presume it's some sort of table, but I'd have to do much more reverse engineering on this firmware file than I have the skill for to figure out how it works). Jumping to the section containing strings pertaining to the Exam Mode menu, you'll curiously find that all five regions - France included - exist here:


While doing this, I did interestingly find that both calculators identify themselves as a CP400 according to lsusb.

The CG100 is running version 02.00.0202 with MPM installed, while the GM+ is running version 02.10.2202

Considering that both the GM+ and CG100 use the same updater (and hence the same firmware file), I do believe this points to the calculator itself deciding whether it's a GM+ or a CG100.
I suppose the question I want to ask here is how does it decide that?

For reference, I have attached an image of what shows up on either calculator when you press "Enter Exam Mode"

I do apologise if this question is a little noobish or whatever - I simply find this quite intriguing