You might be the reason for my story. I helped a bunch of other people cheat but I didn’t, and it was not directly intentional.
We had TI-89s too but we were required to erase all memory and show the output message to the teacher to be allowed to use it.
I was really into some game on my calculator and didn’t want to lose it from wiping my memory. So, I wrote a program that would mimic all the steps as if you erased it and return the same output at the end. Everybody was asking me to share it and they used it on the next test. I did too but I didn’t have anything saved to use to cheat.
Really depends on the restaurant.
The smaller or local places where we are have all mostly switched to the handheld mobile devices.
The fast food places are all still front register POS style.
The larger chains or fancier restaurants are mostly still take your card away and run it then return for a signature.
I imagine the holdouts either don’t want to make the technological and cost investment to update (big chains) or they feel the mobile device is too “low class” (fancier restaurants).