Basic TI-Nspire and TI-Nspire CAS share the same hardware. Yet, installing a CAS OS on a basic TI-Nspire is not possible, nor is possible installing a basic OS on a TI-Nspire CAS. Thus, this impossibility is not due to the hardware but to many software protections without which TI wouldn't be serious when selling both models at different prices.
The TI community always wanted to use TI calculators at their best and long looked for using a CAS OS on a basic TI-Nspire.
The
first solution was found using Ndless 2.0, a software -
whose creator wishes to stay anonymous - decrypting the OS on computer and the little calculator software OSLauncher, developed by Lionel Debroux. Starting from a basic TI-Nspire with OS 1.7, 2.0.1 or 2.1.0 and running Ndless 2.0, it was possible to launch the CAS version of the OS sharing the same number and vice versa.
Note that the OS was only launched - not installed. The mod was temporary, cancelled by any reboot of the calculator.
Since OS 3.0.1, installing an OS 2.1 or older isn't possible anymore - officially. This is due to a minimum installable version number written in the NAND chip in a zone out of the file system. Even though there is an
unofficial method to get rid of this problem, this method cannot be used on TI-Nspire CX, as the first OS supported by their new hardware is 3.0.1.
From now on, this is not Lionel but Compu who
updates OSlauncher for using it with Ndless 3.1.
We did not write much about it because of many inconveniences of this new version, making it almost impossible to use for most users:
- OS launching fails most of the time (95%)
- you have to put the launching program in the Ndless startup folder to increase the success rate
- OSes 3.1 and 3.2 just freeze when hot-launched - you can only launch OSes 3.0.1 and 3.0.2, which are different from OS 3.1 and mess the ressources id:
- like the above version, the mod is temporary and cancelled by any reboot
- you have to reinstall Ndless on the hotlaunched OS and cannot do it from the calculator
- and finally, it doesn't work on TI-Nspire CX at all
In a
previous news, I revealed that my basic TI-Nspire prototypes were detected as TI-Nspire CAS when using OS 3.1 or later.
Such an information must have gone unnoticed this summer, yet everything finally came clear in my head. A routine detecting the type of hardware has been changed since OS 3.1, making OSLauncher not working anymore. We may suppose that OS 3.1 was modified for this purpose, using the updated routine on the OS startup.
This -apparently useless - information made us find today a way of changing permanently a basic TI-Nspire prototype in a TI-Nspire CAS !
Once again, TI-Planet achieves what was impossible !
What was so different between my TI-Nspire prototypes and the commercial versions ?
Let's have a further look using a software that I made :
TI-Nspire identify themselves with two values:
- an id of the model, stored in the NAND
- a bit stored in the ASIC chip, giving again the type - basic or CAS - of the model
The model ID stored in NAND specifies entirely the TI-Nspire model:
- 0C for TI-Nspire CAS
- 0D for TI-Nspire Lab Station Cradle
- 0E for TI-Nspire
- 0F for TI-Nspire CX CAS
- 10 for TI-Nspire CX
- 11 for TI-Nspire CM CAS
- 12 for TI-Nspire CM
The model type, store in the ASIC chip, respecifies if the TI-Nspire is CAS or basic:
- 0 for a basic TI-Nspire
- 1 for a TI-Nspire CAS
Permanently modding a TI-Nspire model into another one sharing the same hardware can be achieved by changing these two values.
It is possible for the id stored in the NAND, which is publicly documented. We already did something like that for
modifying the Boot2, the
diagnostic software or even for
reinstalling previous versions of the OS.
However, the ASIC is that fat undocumented chip from TI.
Unfortunately, even if we had documentation, we don't even know if this chip is flashable...
Let's get back to my basic TI-Nspire prototypes, identified as TI-Nspire CAS by the computer since OS 3.1.
There must be something looking more like "CAS" on them... Everything looks normal on the
About... screen, which shows an id starting with 0E :
But if we use the software previously used...
... we finally find the difference ! The ASIC chip doesn't have the value giving the type of the model, which defaults here to all bits high.
On these prototypes, changing only the id in the NAND should change them in CAS models. Let's do it using the tool menu!
The calculators can then be rebooted: they will remove the basic OS and wait for a new CAS OS to be sent.
Here's a video with such a modded TI-Nspire prototype on which you'll see that the mod is permanent as I reboot the calculator:
It took us time, but people who were scammed into buying TI-Nspire prototypes online finally get something far more interesting than production Nspire! Source with access to fullsize images and to the tool download page:
http://tiplanet.org/forum/viewtopic.php?t=10331&lang=enMany thanks to Bisam and SilverOne for helping me translating this big news into english.Many thanks to Bsl, Goplat and Jimbauwens, who made me able to develop this tool after exchanging about dumping/flashing for several years now.
