I've got one around somewhere. Back in '84 in high school, I was carrying it around in my backpack playing around with it and was on my way to my physics final and dropped my TI calculator and smashed it to bits. I wound up taking the final using the slide rule. Made an 'A' too. My first day at Texas A&M I bought an HP 41C calculator. I still use it frequently, and it's still on the original batteries. That thing is a tank.