I had a 15C in high school as well, as my father was a geek and told me he'd only buy me a calculator if it was RPN. I loved it, but I wore it out by the time

I had a 15C in high school as well, as my father was a geek and told me he'd only buy me a calculator if it was RPN. I loved it, but I wore it out by the time I got to college and I replaced it with a 32SII. I've still got that one, but it long since died and won't turn on.