Texas Instruments borked programming support for its calculators and hobbyists are mad

Cal Jeffrey

Posts: 2,398   +553
Staff member

Last week, Cemetech reported that Texas Instruments had patched out the ability to execute programs written in assembly language (ASM) or C. The move threw the TI-enthusiast community into an uproar.

After the firmware update, attempting to run any ASM or C program returns an error (below) reading, "Error: Invalid. Attempted to use a variable or function where it is not valid." According to a support email posted by TI-Planet, only the TI-84 Plus CE, TI-83 Plus CE-T, and the TI-83 Premium CE are affected.

According to a poster on Linus Tech Tips, Texas instruments removed the functionality in response to a video posted by a student and teacher showing how one can bypass Exam Mode on the calculators. Since TI prides itself on its testing security, it pulled support for the two programming languages.

The problem is that the video demonstrating the exploit used a calculator running a long-outdated version of the OS (5.2.2). The current operating system is 5.5.1 and will be the default in new calcualtors going forward. The poster's argument is that the video used software that was "obsolete" before the release of 5.5.1.

Furthermore, the enthusiast community has worked with TI for many years, sharing flaws like this privately with the company. That way, TI developers can patch exploits before they are revealed publically, like what just happened.

After the video was released, the community reached out to Texas Instruments, which assured them it would not do something as drastic as restricting the languages. Indeed, in the 5.5.0 beta, everything was intact. However, upon the public rollout, TI had revised the OS to 5.5.1 and removed the support for ASM and C. The calculators still run TI-BASIC and Python, but these languages are far too slow for advanced programming.

"It's the slowest Python implementation in a calculator," noted Cemetech. "TI-Planet clocked the put_pixel() fill rate at 48 pixels per seconds [sic]. The next two best calculators are 100x to 200x times faster. The next one is 1000x times faster."

The lowered performance makes simple ray-tracing and fractal programs impossible.

To make matters worse, removing the languages did not even fix the problem, say hobbyists on Planet Casio. Students can still modify hardware to rig the Exam Mode LED. They can also use outdated firmware since testing sites do not generally check to see that calculators are running the most current operating system.

For now, TI-programming enthusiasts will have to avoid updating for as long as possible. However, the community hopes to raise "enough negative backlash" to have Texas Instruments reinstate the support.

Image credit: CalcPlex

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summermick

Posts: 27   +35
I remember this taking calculus in high school and my teacher required us to buy TI-89, which we could and would use in AP exam and colleges...and when I went to college, my professors only allowed us to use TI-30 and also there is the TI 89 emulator. TI-89 is only for high school calculus students. I wonder who actually uses TI-89 on a daily basis.
 

brucek

Posts: 398   +443
If your test (or worse, your entire course) can be rendered obsolete by a programmable calculator, I'd start by fixing the test/course.

The world has programmable calculators and even smarter devices. Education should be about what the human can accomplish on top of those tools.
 
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p51d007

Posts: 2,423   +1,696
I remember the first programable LED calculator I had in the late 70's. Before any test, the teacher would make us pull the battery, to make sure we didn't have anything pre-programmed.
 

Evernessince

Posts: 5,103   +5,355
All exam equipment should be provided by those conducting the exam, especially when it comes to electronics.

Unless the devices can be exploited on site this should not be a huge deal.
 
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fadingfool

Posts: 154   +154
Over here on the other side of the pond Casio was the mainstay calculator of choice for A-levels and Bachelor degree in the late 80s. My Fx 7000GA got me through A-level and its bigger brother the fx7700G got me through my degree. You only had 422 bytes to play with (Basic-esque language) on the 7000 which was enough for a simple quadratic equation solver and not much else so there wasn't a lot of scope for cheating..... Got to give the kids some kudos if they are programming their way around restrictions - maybe fail the subject they are taking but give extra credit in their computer science course work...
 
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mbrowne5061

Posts: 1,483   +822
Over here on the other side of the pond Casio was the mainstay calculator of choice for A-levels and Bachelor degree in the late 80s. My Fx 7000GA got me through A-level and its bigger brother the fx7700G got me through my degree. You only had 422 bytes to play with (Basic-esque language) on the 7000 which was enough for a simple quadratic equation solver and not much else so there wasn't a lot of scope for cheating..... Got to give the kids some kudos if they are programming their way around restrictions - maybe fail the subject they are taking but give extra credit in their computer science course work...
The argument for 'give them a pass for the course' is if you programmed a calculator to do your math for you, you must really understand the material.

I don't personally agree with this argument, especially since you can just install a program someone else wrote (without understanding it) these days, but that's the argument.