uninstall Ndless

[hastern]

As I collect handhelds at year end, I see that some students have installed Ndless.

Are there any procedures to uninstall this beyond deleting?

[hastern]

OS was 3.2.3, so I think maybe Ndless wasn't actually running.  but still would like to make sure with someone more conversant in the program.

[Lionel Debroux]

Hi,

> OS was 3.2.3, so I think maybe Ndless wasn't actually running.

Indeed, the third generation of Ndless works only on OS 3.1.0.392.

> Are there any procedures to uninstall this beyond deleting?

N/A if the calculators were running OS 3.2.3... but the procedure for
uninstalling Ndless has obviously always been described in the README ;)

Ndless and nLaunch / nLaunch CX / nLaunchy do not prevent anyone from
using the heavy hammer: enter the maintenance menu on each individual
calculator, reformat the entire memory, and transfer a fresh OS upgrade.


On a side note: transferring a fresh OS upgrade, tailored to the
standardized test's restrictions, is how standardized tests should
always have been handled on the Nspire...
Implementing the PTT mode, which was proven last year to be trivial to
tamper with, was a waste of resources... and we saw this year that
erasing the OS + sending a fresh OS upgrade is the only way to get rid
of nLaunch / nLaunch CX / nLaunchy, which are legal because they enable
running Linux on the calculator, but they also enable "permanently"
installing the CAS OS on the non-CAS model in a reboot-proof manner.
Are the standardized testing regulation authorities even aware of that
fact, which I already mentioned on the group earlier this year ?


Lionel.

[alcoonslists]

Lionel,

Can you fill me in/remind me about bypassing the PTT? How would a student do that with an up-to-date OS? Or if it is not appropriate to give the details here, my question is can you break PTT without loading an alternate OS?

Thanks,

Al
-------------------------
Albert Coons
aco...@bbns.org
Buckingham Browne & Nichols School
Gerry's Landing Road
Cambridge, MA 02138
(617) 800-2264

AP Statistics Web Site: www.bbn-school.org/us/math/ap_stats

> --
> --
> To post to this group, send email to tins...@googlegroups.com
> To unsubscribe send email to tinspire+u...@googlegroups.com
> For more options, visit this group at
> http://groups.google.com.au/group/tinspire?hl=en-GB?hl=en-GB
> The tns documents shared by group members are archived at
> https://sites.google.com/site/tinspiregroup/classroom-news/welcome-abouttime
>
> ---
> You received this message because you are subscribed to the Google Groups "tinspire" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to tinspire+u...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>

[hastern]

thank you.
since I didn't download or install this stuff, I didn't have the readme or faq handy.
appreciate your help.

Howard.

[Lionel Debroux]

Hi,

> Can you fill me in/remind me about bypassing the PTT?

Starting from June 2012, immediately after the release of OS 3.2.0.1212,
multiple independent programs tampering with the PTT mode in OS
3.1.0.392 were released on the community's message boards. The short
timespan between the release of OS 3.2.0.1212 and the release of the
PTTKillers leaves no doubt, the PTTKillers are a retaliation to TI not
listening to users and trying to curb valid, alternate uses of their
platform.
The programs were censored by moderators, obviously, but several dozens
of copies were downloaded nevertheless. All programs were simple in
concept and in implementation (like my original OSLauncher from spring
2011), they usually provided access to user documents and native code
programs while in PTT mode.

> How would a student do that with an up-to-date OS?

It could easily be done if the up-to-date OS is installed + launched
through nLaunch / nLaunch CX / nLaunchy.
Tampering with the PTT or running the CAS OS on the models sold as
non-CAS is not the main goal of these tools (at least, that's what we
can guess from the fact that the anonymous, unknown authors of nLaunch
and nLaunch CX did not boast about their program's ability to kill all
protections, although the programs do), but they enable doing it.

Before launching the OS, these programs patch the OS to adjust a
filename, and on OS 3.1.0.392, to optionally install Ndless. They could
perform other arbitrary patches, including fiddling with the PTT in more
or less detectable ways. From the moment arbitrary code can be executed
on a platform, it can modify arbitrary code and data and thereby
influence behaviour in arbitrary ways.

And since getting rid of the three nLaunch requires removing the OS and
transferring a fresh one, reflashing right in the exam testing room (at
least the calculators which can be brought from home to the testing room
by students) is the only solution, assuming it is /really/ important
that the test be taken without a CAS.

> Or if it is not appropriate to give the details here, my question is
> can you break PTT without loading an alternate OS?

Since Ndless and the three nLaunch (which can, among other effects, be
used to break the PTT, but also have plenty of valid, legal uses - which
is why TI isn't attacking the community's websites, they have hopefully
learnt the lesson of the "TI signing key controversy") involve a crafted
OS upgrade, I guess I should answer, strictly speaking, "not that I know
of".
If by "alternate OS", you mean Linux + userspace (and external
CAS-capable software)... indeed, this will have no PTT-type restrictions.
But I'm not confident I have understood your question, and therefore,
not confident that I'm replying correctly... perhaps my reply to your
second question contains what you're looking for ?


Bye,
Lionel.

[alcoonslists]

Thanks for the great detail. So, if I am reading between the lines, I would tell the teachers in my department (who are users, but not technical users) of the NSpire that:

1) Students can load a program into the Nspire which,
2) Even when they go into PTT mode after arriving for a test,
3) allows them to access documents.

To avoid this we would have to have them essentially reload the OS when they arrive.

Do I have the gist of it?
---------
Also, how would a teacher (easily?) identify a calculator with this ability or in this mode, or is that not obvious?

Thanks,

Al
-------------------------
Albert Coons
aco...@bbns.org
Buckingham Browne & Nichols School
Gerry's Landing Road
Cambridge, MA 02138
(617) 800-2264

AP Statistics Web Site: www.bbn-school.org/us/math/ap_stats

[alcoonslists]

1. Anyone have any idea about the normal summer major update to the computer software and HH OS?

2. Anyone else have problems with the software running on Mac OS 10.8.3 as follows:

a) Not quitting correctly (hanging), and
b) When launching the software by double clicking a tns document, having the software launch into a blank document (not the document you double clicked). If you then double click the document again it is loaded into the software.

I identified these problems quite a while ago and let TI know.

PS. Happens on different Macs and different Mac OSs.

Thanks,

Al

[Adriweb]

On Wednesday, June 5, 2013 2:27:28 PM UTC+2, Al Coons wrote:

Thanks for the great detail.  So, if I am reading between the lines, I would tell the teachers in my department (who are users, but not technical users) of the NSpire that:

1)  Students can load a program into the Nspire which,  

2) Even when they go into PTT mode after arriving for a test,
3) allows them to access documents.

Correct if students know about ndless, know about this hack and also find a way to actually download the files somewhere (as said before, they get censored rapidly), and know how to enable it

 

To avoid this we would have to have them essentially reload the OS when they arrive.

Correct.

PTT hacks are generally done (well, the ones I've been able to look at, since they diseappear quite fast) effective by putting them into the (Ndless') "startup" folder so that, as Lionel said, they can copy the actual documents to the other virtual PTT root. Before going in PTT, one could check of there is a PTT-hack in such a folder. But maybe there have been some other hacks that I don't know of that act differently.

 

--------- 
Also, how would a teacher (easily?) identify a calculator with this ability or in this mode, or is that not obvious?

Pretty much by going to the document browser and see if any files are here ?

 

Adrien Bertrand ("Adriweb")

[Lionel Debroux]

> > Thanks for the great detail. So, if I am reading between the
> > lines, I would tell the teachers in my department (who are users,
> > but not technical users) of the NSpire that:
> >
> > 1) Students can load a program into the Nspire which,
> > 2) Even when they go into PTT mode after arriving for a test,
> > 3) allows them to access documents.
> >
> Correct if students know about ndless, know about this hack and also
> find a way to actually download the files somewhere (as said before,
> they get censored rapidly), and know how to enable it

Or can make such files by themselves and share them across a group of
students. The programs that we've seen are simple in concept and
implementation, showing that tampering with the PTT mode is easy.

> > To avoid this we would have to have them essentially reload the OS
> > when they arrive.
> >
> Correct.
> PTT hacks are generally done (well, the ones I've been able to look
> at, since they diseappear quite fast) effective by putting them into
> the (Ndless') "startup" folder so that, as Lionel said, they can copy
> the actual documents to the other virtual PTT root. Before going in
> PTT, one could check of there is a PTT-hack in such a folder. But
> maybe there have been some other hacks that I don't know of that act
> differently.
>
>
> > ---------
> > Also, how would a teacher (easily?) identify a calculator with
> > this ability or in this mode, or is that not obvious?
> Pretty much by going to the document browser and see if any files
> are here ?

Yeah, that's probably the easiest way to detect most of the programs
that we've seen so far. But there could be programs aiming at being more
stealthy. For instance, patching out the tests + branches which disable
some math functionality while in PTT mode wouldn't be detectable through
the document browser.


Trustworthiness of a given calculator model in a given standardized test
is a problem, which will only get worse with the increasingly complex
pieces of hardware and software that calculators are. TI, as the market
leader in many countries, is more impacted than the other manufacturers,
but all manufacturers are hit by the problem.

One way to solve the problem would be to make teaching and exams closer
to the real world, simplify the rules, and save everyone money, by:
* nuking silly artificial restrictions such as "no CAS", "no trig
functions", etc. The French school system is far from being perfect, but
that's something we get right, IMO.
* letting users use auxiliary programs and documents, of course. We
can do that in the main standardized test in France.
* as a consequence, eliminating the need for protection modes, for
separated non-CAS and CAS OS and models, for reflashing calculators in
the exam room, etc.
In the real world, when solving real-world problems, getting the result
right, and providing a proper explanation, usually requires knowing the
basics (the theory behind the result) anyway. Calculators are great
tools, but one needs to check the orders of magnitude and whether a
result / solution feels good, on various criteria (when attempting to do
things correctly, at least).
If the exam's questions are done the right way, calculators help those
who know their stuff, and don't help (or even hamper, by slowing them
down) those who don't.


Alternatively, it's possible to persist in error, in exams disconnected
from real-world problem solving, in failed attempts to restrict
functionality, and nevertheless have to resort to high-cost and
heavy-handed measures such as erasing the entire contents of the NAND
Flash memory through the maintenance menu, and reflash an OS upgrade
tailored to the exam's needs (forbidden functionality merely compiled
out), right before the exam is taken, just in case.
I strongly doubt that the undermined models can be banned outright,
especially if they're in widespread use, because it would severely
distort the exam's fairness: an allowed calculator model is used for
most of the school year, so students get used to it; but several weeks
before the exam, it becomes forbidden ???

Note that this in this direction as well, special testing modes and
suchlike half-measures are eliminated as well, by treating anything as
untrustworthy (like the Nspire series is, even if TI keeps trying to
achieve this aim, nLaunch shows that they have royally failed) and
therefore simply reflashing the calculators with a tailor-made OS.
This will bear high, recurrent costs, obviously.


Ramblings over :)
Lionel.