(Edit: I am assuming you were asking how it's possible I didn't use it, not how it's possible that people were copying programs onto their calculators.)

I don't know. It's been too long. We must have done graphing on paper.

I don't remember a lot of coursework in math that required me to produce a decimal value. For example, we wanted √2 instead of 1.414.

In physics, I think we used regular calculators.

I used to be bewildered at my parents not remembering certain things from high school. But, now I'm living it :).