Boot2 downgrade

[Xadhoom]

Hi guys, I have a problem with my ti nspire cas touchpad (the black one). When I bought it two years ago it had the 2.1 version of the os. I don't know why, but following the update guide on the texas instruments site something went wrong. The 3.0 update installed made the handheld believe that she is a clickpad one and not a touchpad, so I have that different key mapping.
After some resets, re install, update try (now it has 3.6 os on it) i discovered on the forum that the error may lay in the boot2 installation. At that time I tried to downgrade via the serial port, following the online guides and using a b75937 usb-ttl adapter (it has a CP2102 chip on it) but with hyperterminal I didn't manage to get a connection.

Now I ask you:
It's my specific usb-ttl that it's not right for this?
In alternative I have an Arduino UNO board, could be more effective?
It's hyperterminal fault?
I read about lrzsz, in alternative to hyperterminal. I installed cygwin for using it on windows 8, but I don't know how to use it. Could someone explain me?
Alternatively, there is an equivalent program that I can use on mac OSX instead of Windows 8?

Thanks for reading!

[critor]

Downgrading the Boot2 won't be that simple, as OS 3.6 is going to reflash it the next time it boots.

You need to use Nlaunchy to prevent this.
If you have OS 3.6 and can install Ndless, you can downgrade the Boot2 though software, using the nsNandMgr tool :
archives_voir.php?id=10080

But I'm not sure the Touchpad keypad being recognized as a Clickpad keypad problem is related to the Boot2.
Usually it's :

• either that the keypad is not firmly inserted (or that there is a problem with the connection)
• either that you have a TI-Nspire TouchPad prototype (development model) - they use a different Touchpad keypad whose support was dropped in early 2.x versions

[Xadhoom]

Thanks for the answer!

For a better identification of my model, I took some photos:

https://onedrive.live.com/redir?resid=5 ... lder%2cjpg

I don't know if it's a prototype, I saw other nspire cas touchpad and seemed identical to mine.
And before the first update to 3.0 the handheld worked properly, even the touchpad was fine.

I managed to install ndless, download boot2 1.4 from this site and start nsNandMgr. As the readme says I put boot2 in the ndless folder, but I don't know the procedure to replace boot2 3 with 1.4.

[critor]

Thank you for your photos.


Unfortunately, you got a prototype - according to the "DVT" and "EVT" strings in the serials on the back of the calculator and of the keypad.

The last known TI-Nspire OS supporting the included special "touch" circuit is 2.0.0.1188.
Support was removed before OS 2.0.1.

So the only known options would be :

• either downgrade to OS 2.0.0.1188
• or get and use a ClickPad keypad

[Xadhoom]

So, the mistery is finally solved, thank you VERY MUCH

I was already thinking about getting a clickpad keypad, on ebay.com there are many on sale for 5 dollars plus shipping.
But I would prefer to downgrade in order to have the original functionality and appeareance of the calculator.
In order to downgrade to OS 2.0.0.1188, I have to do it via usb-ttl adaptor, or I can use nsNandMgr to remove the minimal installable OS downgrade protection?

In the first case, there is a better program than hyperterminal that works with windows 8 or mac osx?

[critor]

You just need to remove the downgrade protection with nsNandMgr, and then to send OS 2.0.0.1188.

[Xadhoom]

ok, yesterday I tried to remove the downgrade protection, but the program said that boot2 was invalid and to reboot.
Today I retried and did these steps:

install ndless
start nsNandMgr
removed the downgrade protection (for a second the screen changed, I managed to read NAND and some other things)
tried to send tinspirecas_2.0.0.1188.tnc via tinspire computer link software, but the update was rejected as it said it was an invalid OS

retrying again (3rd time) the procedure I accidentally swapped the Boot2/Diag boot order, and couldn't manage to reverse it with the same menu option. Rebooting the handheld now shows the diagnostic menu, and now I don't know how to get back to the OS.
This happened even yesterday, but I don't know how I managed to exit the diag menu: the problem is that with the limited functionality of the keyboard I can't press arrows, and so I am blocked when it asks to press them.

[critor]

Yeah, it's normal.
OS 3.6 does reject every older OS by itseld.

You need to :

1. install OS 3.6
2. install Ndless 3.6
3. install nsNandMgr
4. run nsNandMgr, ask it to remove or reset the downgrade protection, and confirm it did succeed
5. remove OS 3.6 using the maintenance menu (hold while pressing and releasing 'reset' on the back - menu should appear at around 50-60% of the loading bar - don't let the loading bar reach 100% and OS 3.6 restart, as the downgrade protection will be back)
6. send the older 2.0.0.1188 OS at the Boot2 "Install OS" screen

[Xadhoom]

I did all the steps, but the computer link software refuses to install the OS (I used the 2.0.0.1188 tnc file found in the download section).
Now I will reinstall 3.6 (i assume that all versions are good, I'll try with OS TI-Nspire™ CX CAS (v 3.6.0.546)) and redo the procedure.

On step 4, how do I confirm that the removal of downgrade protection had succeded?

Thank you again for all your help

[Xadhoom]

Ok, I don't know what's wrong but I can't install 2.0.0.1188. I did all the steps listed above, but nothing. Where I could be wrong?