TI-Nspire Hack Enables User Programming

An anonymous reader writes "Texas Instruments' most recent, ARM-based series of graphing calculators, the TI-Nspire line, has long resisted users' efforts to run their own software. (Unlike other TI calculator models, which can be programmed either in BASIC, C, or assembly language, the Nspire only supports an extremely limited form of BASIC.) A bug in the Nspire's OS was recently discovered, however, which can be exploited to execute arbitrary machine code. Now the first version of a tool called Ndless has been released, enabling users, for the first time, to write and run their own C and assembly programs on the device. This opens up exciting new possibilities for these devices, which are extremely powerful compared to TI's other calculator offerings, but (thanks to the built-in software's limitations) have hitherto been largely ignored by the calculator programming community."

Comments

Re:WHY?

[fuzzyfuzzyfungus]

Either it is reflexive control freakery or, more likely, it has to do with the demands of standardized testing.

TI's calculator division makes its money(and justifies its margins, I'm not sure that the price of a TI-83 has fallen to anything except inflation since I had to buy one back in secondary school) by being the de-facto standard calculator for education. Sure, a few of the hardcore nerds in engineering still have their HP somethings, and anybody doing real crunching will graduate to a full computer running one of the mathematical packages; but TI is it everywhere else.

The Wikipedia page mentions several features aimed specifically at educational testing: "The TI-Nspire also features a "testing mode" LED indicator, designed to stop potential cheating, informing test supervisors that the calculator is still denying access to saved files and possibly restricting geometry features on the handheld during the test. It also features a timer. At the end of a test, the supervisor is required to check the calculator's timer to see if it has not been removed out of "testing mode"." Essentially, because it is commonly used on tests, the educational customers who drive most of the sales(directly or indirectly, some districts purchase, some mandate, some just encourage) would really like the calculator to be a "trusted" black box capable of doing only what it says on the tin, not doing arbitrary computer tasks(like storing notes, or doing symbolic integration and differentiation when the kids are supposed to be learning that).

If it is possible for people to write their own stuff, in something more than a crippled little scripting language, it becomes possible to subvert these testing controls.

Re:ti in the past never really supported assembly/

[langelgjm]

What's more, TI actually released assembly programs that would install new features on the calculator. I have a TI-86 from years ago and just recently installed a TI-provided statistics package that gives me the various distributions, test, etc.