Hi and welcome to the forums

Q1: Nope, Ndless requires a copy of OS 3.1 or 3.6 to be installed.

Q2: Don't install OS 3.9 if you plan to use Ndless. There's no way to downgrade back to 3.6 if you do so (except with extra hardware if your calculator is old enough and even then it's not guaranted)


I recommend OS 3.1 or 3.6 personally.

Do you mean the non-CAS CX handheld? I unfortunately don't know how to switch from a CAS OS back to a non-CAS one if you have the non-CAS model, but if you meant the CAS model, then there is probably an option somewhere to locate the OS file on your computer. I think it's a .tco file (or .tcc if you got a CAS model). Just don't use the Find updates/Update unit options in the menus because that will install OS 3.9, which you don't want to happen.

If you literally want to remove the 3.2 OS before installing 3.6, then you need to access the maintenance menu and remove the OS from there. I forgot the key combination, though since I don't use my TI-Nspire CX much. It's probably somewhere online or on the forums.

Ok I think I found it: https://github.com/Excale/nLaunchy

In the readme file, you need to follow the Uninstallation steps. Also, to access the maintenance menu, I found the key combo and it's Doc+Enter+EE. While holding these down (your fingers must be 15 inches long ), use a pen to push the reset button on the back and keep holding the Doc+Enter+EE down until the maintenance menu appears.

AFAIK it's not possible right now to use 3.6 CAS on non-CAS HW.