TI Calculator DRM Defeated

josath writes "Texas Instruments' flagship calculator, the Nspire, was hacked to allow user-written programs earlier this year. Earlier this month, TI released an update to the OS that runs on the calculator, providing no new features, but only blocking the previous hack. Now, just a few weeks later, Nleash has been released, which defeats this protection. The battle rages on as users fight for the right to run their own software on their own hardware."

Re:at the end of the day:

[Ash Vince]

As for calculators, they should not be allowed on exams at all, or in classrooms. Math is not about pushing buttons, and if every math problem (even in physics and chemistry) a student encountered required them to find a solution without the assistance of a calculator, we would not have to water down math exams just to ensure that more than 50% of the students pass (maybe I am being a bit optimistic about the extra practice...).

You are obviously to young to know that engineers have always used calculators. Before these new fangled electronic things people used slide rules, they could do almosy as much as a modern calculator.

http://en.wikipedia.org/wiki/Slide_rule [wikipedia.org]

Re:Not to Diminish the Achievement...

[Anonymous Coward]

Because they're commonly used for standardised testing. YOU try to convince a high school teacher you aren't going to cheat on your internet enabled multi application device.

Re:why?

[h3nning]

10 years ago when I was at a university they also said that they would reset to factory defaults, this never ever happened, though. Probably because senior citizens are hired to supervise exams here in Norway.

Also, even if they did, the calculator I had could store data and programs in flash, which wouldn't be affected by a factory reset.

The only way a factory reset would have affected me was that I would have had to turn RPN back on.

Re:Just fake the UI

[nattt]

We just used to slot some cardboard or sheet plastic in the back of the calculator - Casio fx7000-G so that when the teach pushed a pen in to hit the rest switch, it just hit the plastic and didn't reset the calculator.

Re:what

[Firethorn]

Pushing reset results in visible screen changes. You can both have firmware fake a reset in that case or have the cheating system embedded into the firmware.

If the calculator won't reset, then they're either going to do a closer check for cheat stuff or just not let you have the calculator(hope you brought a backup!).

Re:Solution

[Vahokif]

Well they can do that now. There must be a way of making a case that you can't open without breaking it.

Re:what

[BrokenHalo]

I don't know anything about the nSpire, but my TI-89 has a few different ways of resetting it, some more pervasive than others. The most common key-sequence results in the appearance of a progress-bar thingy for a few seconds, and the UI reverts to the default, and programs, expressions or variables assigned to general memory are deleted. However, programs (user-generated or otherwise) assigned to so-called "archive" memory are not deleted, so a simple script to restore your favourite settings is easy enough to maintain.

Re:what

[FluffyArmada]

The nspire is actually pretty freaking smart about resetting. Instead of actually needing to do a full reset, it has a fancy test-taking mode. You hold down the escape+home(on) key while the calculator is turned off, then you'll get a dialogue asking if you want to enter 'press to test' mode. Once you enter that mode, the calculator resets, and reloads the firmware without deleting anything you've been working on, and a little led on the end of the calculator will blink every few seconds to show that you're in the right mode. And then, the only way to exit the mode is to plug the calculator into either another calculator or a computer with the TI software. But, once you exit the testing mode, all of your stuff will be right where you left it. It can be a huge pain in the ass, but honestly, if TI wants to make cheating really hard, this is sure a good way to do it. Of course, once the DRM on the calculator is defeated... it's going to be fairly trivial to replace the testing image with something more useful... or even just use some assembly code to flash the led.