Ndless is back for OS 3.9!

You should actually forget OS 3.9 which doesn’t bring anything interesting for users expect the usual anti-Ndless/anti-downgrade protection.

Get the new DowngradeFix 3.9 to uninstall OS 3.9 and (re)install OS 3.6, compatible with Ndless 3.6, the TI-Nspire calculator jailbreak. Make sure to follow all the steps described in the tutorial.

Many thanks to the usual enthusiasts who worked  hard on it behind the scenes.

You will now be able to try out the Ndless-powered MicroPython port and its PyWrite editor. Python is an interesting alternative to Lua and the #1 programming language for learning programming.

downgradefix 3.9

22 thoughts on “Ndless is back for OS 3.9!

  1. My TI-Nspire CX CAS does not appear in the TI software after it shows “Downgrade protection disabled” after I’ve replugged in the calculator to the computer, is anyone else having this problem?

    1. This may happen time to time. Here are the steps to follow:

      • Press the reset button on the back of the calculator. Let the calculator reboot.
      • If diags software shows up instead of the OS, select option “0. Additional function”, then “Go to OS mode”. Reset again the calculator with the reset button on its back.
      • Try again DowngradeFix which should now work.
      1. Yeah I ran into the diagnostics screen a few times while trying this, I ended up playing around with the timing of when I disconnected the cable and reconnected it to finally be able to try and install OS 3.6. My installation of 3.6 ended up getting stuck, so I reset my calculator and it said it didn’t have an OS on it when it rebooted so I just installed 3.6 at that point. Probably not the most ideal way to use this tool (i.e. basically corrupting OS 3.9 to be able to install 3.6 again) but oh well, I’ve got ndless on my calculator now so who cares! :D

      1. After putting the downgrade fix on my calculator, (if I recall correctly, you might want to try different combinations of timing when you disconnect the cable if this doesn’t work for you) I left the the calculator plugged in, ran the program from the calculator, then when it said connect the calculator, I unplugged it then replugged it in and I’m pretty sure it still detected it then. But like I said, if that doesn’t work for you, try and keep the cable in longer or shorter or unplug it sooner or later, there’s got to be a combination that works for you. Hope that helps.

    1. Quoting my answer on omnimaga : The decision to release a downgrade utility was made to avoid uselessly investing time into an upgrade of Ndless for this OS version which doesn’t bring us anything new, and which would require much more effort.

  2. My new Ti Nspire CX with trailing letter “S” is not stable on anything lower than the factory The downgrade is always successful but after downgrading I cannot disconnect my CX from a power source (computer or charger) without it going into a reboot cycle.

    I have tried 3.9.0.xx and 3.6.xx.

  3. I am having a NEW nspire CX CAS ending with a T— which is not supported for the downgrade. Are there anything for me to do? I REALLY want to install Ndless on it…

  4. Look, I had OS and used endless to get 3.6 version. But now my TI has a reboot cycle. How can I fix it?

    1. You need to install OS again. Any other OS is not supported on your calc. Ndless 3.9 is available for OS

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