This topic is about jailbreaking the TI-Nspire CAS+ with OS 1.0.554.

Crossposting from TI-Bank and UTI, in case anyone can help with ideas or tests.



I have done some tests for months by my side. Here are my results so far:


1)a) Calculator "Send OS":

The "Send OS" menu is disabled.
Even when you connect the calculator to a computer, to a TI-Nspire/Nspire CAS, or even to another TI-Nspire CAS+.

According to tests I had asked for to Datamath, the "Send OS" menu was enabled on previous CAS+ OSes (1.0.4xx, 1.0.3xx). But I've never seen those older prototypes anywhere outside  the Datamath museum.


1)b) Calculator file architecture:

According to a basic link tool I've developped:

The CAS+ doesn't understand ".." folder
It has no "/phoenix" folder.

Visible folders are only:
"/"
"/phx"
"/phx/documents"
"/phx/tmp"

And nothing interesting in those folders.

So, the OS is not visible in the filesystem.

Notice: with so few files, the systems reports 5.9Mb used in the 27.8Mb Flash file system... Where are those Mb?...


2) Maintenance menu:

Do not try menu+enter+p. It doesn't show a menu, but does remove the OS.


3) Diagnostic menu:

I haven't managed to trigger the diagnostic menu.
With Esc+Menu+G, the calculator just doesn't turn on until you remove the batteries... Strange...


4) Ndless 1.4/1.7:

Great news! Trying to install Ndless 1.4/1.7 crashes the calculator!

You can still move the pointer and turn the calculator off and on.
But that's all.
All other keys seem useless...
And except about the pointer, the screen is not updated and seems frozen: no "low battery" or "low ressources" indicator flashing, no control key flag...

Seems the main program/OS loop is crashed/stucked, but that interrupts are still working.

It would be great to try to install Ndless 1.0/1.1/1.1.1...


5) Computer "Send OS":

The TI-Nspire Computer Link 1.0 looks for ".tnc" OS update files.
If a CAS+ calculator is connected, you immediatly get a "bad file" error when trying to flash the 1.1 CAS OS, or even the 1.1 OS renamed from ".tno" to ".tnc".

I've used a Java decompiler. The sources were not 100% ok (won't compile again - syntax errors), but here is what I have understood about the "Send OS" code. Note, I might be wrong.

- I think the ".tnc" file is not sent to the calculator.
- The ".tnc" file is decompressed on the computer in a temporary folder.
- All included files are sent one by one to the CAS+ in the "/phx/tmp" folder.
- The code checks that you've sent a ".img" file, and a "manifest_img" file.
- Then, the code calls a native method installOS() with the calculator pathes of both above files.

I've made various tests by sending such files to the "/phx/tmp" folder, but the native installOS() just triggers a "Bad File" exception without telling me anything more.

Notice: even after sending severall Mb of data in the "/phx/tmp" folder, the free space remains unchanged.


That's all for today.


I've got 2 identical TI-Nspire CAS+.
If you've got any idea of other interesting tests, just tell me.



What would be interesting to do with the CAS+ is:
- installing Ndless 1.0/1.1/1.1.1
- installing Ndless 1.4/1.7
- dumping/reflashing the 1.0 OS
- dumping the 1.0 boot2
- flashing a 1.1 OS
- flashing a 1.1 boot2

Let's put the blame where it belongs - this is not a bug in OS 2.1; this is a bug in the old version of BOOT2.

When BOOT2 1.1 has finished loading the OS, it calls the memset function, to clear the memory that was used to hold a copy of the TI-Nspire.cer file. But they mistakenly passed to memset the size of TI-Nspire.img instead. If TI-Nspire.img is greater than approximately 5800000 bytes, then memset ends up trying to write past the end of memory, so it crashes. OS 2.1 is the first OS large enough to make this bug visible.

So that doesn't happen with the 2.1 CAS because it doesn't have the TI-84+SE ROM and is a little smaller ?

TI-Bank has newsed about a bug with OS 2.1, which permanently freezes you TI-Nspire basic ClickPad if you've got boot2 1.1.

http://ti.bank.free.fr/index.php?mod=news&ac=commentaires&id=882

If you've owned your calculator for a while and already installed OS 1.4 or newer, you probably have boot2 1.4 and aren't concerned by the problem.

But if you've just bought your calculator, it may come with boot2 1.1...
And when you connect it to your computer, that stupid TI-Nspire Computer Link tells you to install OS 2.1...
Some minutes later, your TI-Nspire is totally useless.

This is a major bug that many Nspire owners most likely ran into since July, when OS 2.1 came out.

@critor: Wow, that's really shitty on TI's part. They really need to fix that.

My posts about that bug on the official french Nspire  forum are just ignored, or are getting rude answers from the moderators (T3 teachers paid by TI), saying that this is not a bug and that I don't know what a bug is...

Your calculator is freezing permanently although you've done nothing unofficial... If it's not a bug, then I guess it's a feature?... :p

(they were trying to explain that it was the users fault, for buying outdated Nspire, and trying to install an OS not supported by the hardware... I guess they don't understand anything, like Ti-Cares...)

Thanks for the clarification.

There is a way to get the 1.1 OS working with a TouchPad keypad on a basic TouchPad.

- install Ndless
- launch a Ndless program, like the particle demo
- hot-swap your ClickPad keypad with a TouchPad keypad

The OS is now working with the TouchPad keypad.
Many keys will be messed up, and the arrow keys won't work at all.
Up to now, there is no fix for that.

But, you'll need the ClickPad keypad again, if your calculator ever reboots...
And I don't remember well, but I think the calculator will reboot if you turn it off then on with the TouchPad keypad...


So, I'm sorry but you need to keep the ClickPad keypad.

Quote from: critor on November 01, 2010, 03:38:16 pm

Quote from: dman2073 on November 01, 2010, 03:33:03 pm

Quote from: critor on November 01, 2010, 03:26:16 pm

On a basic TouchPad:
1) put a ClickPad keypad
2) install OS 2.1
3) send and launch Nleash
4) install OS 1.1

On a CAS TouchPad:
1) install OS 2.1
2) send and launch Nleash
3) install OS 1.1
4) boot OS 1.1 with the TouchPad keypad
5) while the calculator is on, hot-swap the TouchPad keypad with a ClickPad keypad

I followed the instructions exactly but I get an endless reboot.

Have you been able to install OS 1.1?

If the endless reboot happened before that, it means that Nleash didn't work well.
Just use the maintenance menu to remove the OS, and try again.

If the endless reboot happened after installing OS 1.1, the problem comes from the keypad.
Which model are you using: basic or CAS TouchPad ?
With which keypad: ClickPad or TouchPad ?

I'm using a basic touchpad.  I borrowed a clickpad so I could do this

You didn't answer my main question...
Let's say it another way.

Are you trying to say that you are getting continuous reboots with:
- a basic TI-Nspire TouchPad
- and the ClickPad keypad
- and the OS 1.1
?

It has worked for me without any problem.
I've even taken a photo which is available online.
My basic TouchPad datestamp is P-0110A.

What is your datestamp?

Quote from: dman2073 on November 01, 2010, 03:24:37 pm

ScoutDavid- i'm confused is it possible to do it on a regular touchpad?

No, there is no OS 1.1 for the touchpad, it never existed.

?

OS 1.1 does exist...

The only problem is that OSes 2.x which are preinstalled on all TouchPad Nspire install a downgrade protection against all OSes older than 2.0.0.

You just need Nleash to destroy that protection.
It works on both basic and CAS TouchPad Nspire.

Moreover, it's easier to get a usable OS 1.1 on a basic TouchPad than on a CAS TouchPad, as explained above:
http://ourl.ca/7106/135366