I know it is impossible to prevent a calc from sending a program to another calc (or maybe it is), but is it possible to not allow a program to be run on a different calc?

I had an idea where the program is coded to store a bunch of 0's to a variable, and then checks to see if that variable is set to all 0's. If it is, then the program finds some data unique to the device that it's running on, and alters itself to write that to the variable instead of a bunch of 0's. If it's not set to a bunch of 0's then it checks to see if this device's unique data is the same as the coded one to make sure it's the same calculator. If it's not, the program has been transferred from someone else.

I can't find a good tutorial on altering memory with ICE, and don't know if there is a value in the memory that is different for every device, or if you can even edit a program while it's running. Just wanted to know if it was possible.

My idea might be stupid, I don't know much about the calcs other than TI-BASIC and most ICE commands, but nothing dealing with memory. If there's any other ways that might do the same thing, it would be cool to know, I have a TI 84+ CE if you didn't imply that already

In general if you wanted to hardware-lock, the information you'd have to use is the calculator ID. You can retrieve that with syscall 000340.

To edit a program while it's running, you're asking for what we usually refer to as "writeback" where changes to a program in RAM are saved when it exits. I found an old topic about implementing SMC on the CE, which seems to conclude that it works basically the same as on the monochrome calculators.

As for how to do that in ICE.. I don't know nearly enough about ICE to be able to say how, but it's probably doable since it's fairly easy to do in an assembly or C program.

I knew there had to be something unique to all devices, this would work.


Ok, and this doesn't brick the calculator or anything if you do it right, correct?


Yeah, I need to figure out how to use the memory functions with ICE. Thanks, this helped a lot!

Just so you are aware, using the product ID isn't a bullet proof method since a user can change it to whatever they want using CERMASTR: https://tiplanet.org/forum/archives_voir.php?id=1581757