OS 3.2.4. It is not available yet on Texas Instruments' website, but the latest TI-Nspire CX made ​​come with a new OS, the 3.2.4.1237 (source).

The TI-OSes include an "anti-downgrade" protection, a minimal installable OS version that they write in the NAND memory between the Boot2 and the Diags, an inaccessible area to different official reset procedures.

When installing, the OS 3.1.0.392 increases this minimum version to 3.0.2.1785 if the number was lower.
Similarly, the OSes 3.2.0/3.2.2/3.2.3 increase it to 3.1.0.392.

It officially becomes impossible to reinstall an OS version prior to the programmed number.
In practice, it was possible via two methods:

• using a Ndless utility reprogramming itself this version number
• using the nLaunch OS-pitcher who installs and launches the OS completely ignoring that version number

According to  a report this morning on TI-Planet, it seems that the OS 3.2.4.1237 greatly increases the minimum number of installable version that ... to a value which now refuses to install any previous OS to date, including OS 3.1, 3.2.0 or even 3.2.3!  D:

Therefore, if your new TI-Nspire comes with OS 3.2.4 or if you update your calculator with this OS, it officially becomes impossible for you to use Ndless because requiring the OS 3.1 and this just a few days of the exams. :(

The added bonus, the CAS-engine bugs introduced with OS 3.2 and not present on the OS 3.1 such as roots quotients are still here, and the prohibition to return to a version with CAS that worked better is simply incomprehensible from the point of view of users, even just a few days of the exams.

But does it remains always possible to override the anti-downgrade protection with nLaunch?

The OS 3.2.4 contains as added bonus a new version of the boot2: 3.2.4.4 against 3.1.0.16 since the OS 3.1.0.392.

nLaunch exploited a flaw in the boot2 3.1.0.16, and you can bet, I think, that it has been corrected.

Therefore it also becomes officially impossible to use nLaunch and number of legitimate applications like:

• make cohabit the OS 3.1 and 3.2 on the same calculator to enjoy the best of both worlds with both Ndless programs (3.1) and Lua programs (3.2)
  
• Launch a Linux OS

It can be assumed that this OS 3.2.4.1237 is a response to the recent use of TI-Nspire CX launching TI-Nspire CX CAS OSes to the Portuguese exams that prohibit CAS, possibility that allows nLaunch although this has never been the goal of the authors (not mentioned in the ReadMe).

The only feasible and untested bypass to date would be the reprogramming of the boot2 3.1.0.16 via a TTL / USB adapter (called RS232) to connect to the Dock of the TI-Nspire:

So we especially recommend you to not update your calculator to OS 3.2.4, if ever it appeared in the coming days.

And if you already have a TI-Nspire CX with OS 3.2.4, to date you must certainly not erase it. Indeed, as it is not available on TI's website and as all existing OS are rejected, you will find yourself with a calculator without any OS usable! Again, a few days of the exams, it is not very smart ...  ::)

• source of the information on TI-Planet

That's absolutely awful. TI's taking the same route as Apple and I hate it.

I'm not sure to understand your reaction....

What else did you expect from TI ?

(Except the fact that this anti-downgrade protection "surprised" us by coming on a "rare" 3.2.4 and not on 3.6 as expected, granted.)


I guess the purpose of these news is to warn people that they should not update to this 3.2.4 OS if it gets available.


However, for those who already have it and tried to downgrade, and then got stuck without a OS, we've asked TI to give the OS (since it's the only installable version) so that they can at least get out of this issue.

Except the fact that this anti-downgrade protection "surprised" us by coming on a "rare" 3.2.4 and not on 3.6 as expected, granted.

I think that what hapened with portuguese exams made emergency to block nlaunch. The OS 3.6 is not ready yet, so, it's a fast reaction step.

Yes. Excuse me.

I'm not sure to understand your reaction....

What else did you expect from TI ?

To grow up and have seperate builds for Exams only and builds for Users only.

That's absolutely awful. TI's taking the same route as Apple and I hate it.

TI has some kind of a reason : they want their calcs to be accepted in exams (even though as others (like Levak) said, there are other solutions than blocking everything). But Apple doesn't even have any reason.

Anyways, the thing that shocked me is not that TI still didn't change their mind about that stupid idea of blocking everything, but the fact they made that update just before the French exams without providing a way to unbrick a calc one could have tried to downgrade.

This isn't what we're waiting for TI It almost seems like they only see the evil and not the good(games and other tools) in what we do.