This is a picture of my Grandma’s antique calculator, a TI-1200. Grandma used this calculator for over 30 years! Her TI-1200 was made circa 1975, which isn’t as old as I thought, but still pretty old considering that pocket calculators only became popular in the early 1970s. It’s so old that there are instructions on the back (see picture below), illustrating how to do basic calculations, and it was assembled in the USA.
We’ve come a long way since 1975! It’s amazing that we put a man on the moon before there were calculators. Now, most software packages for solving OR problems can be run on a desktop, and there open source resources for solving OR problems.
One of my regrets in life was that I never learned how to use a slide rule. My Dad tried to teach me how to do math with his slide rule, but I used the slide rule as a straight edge until it was no longer usable (Sorry, Dad). I promise to keep Grandma’s calculator safe.