I was gifted this calculator watch by a member of my Facebook Group. I have to say I love it as I always wanted a calculator watch when I was at school in the late 70s early 80s. I never owned one back then but I am sure glad to have one now. NSC stands for National Semiconductor who I know from some many generic LED modules I find in my 70s LED collection. I dont know much more than this so if your reading this and you know a bit of history behind the company I would love to hear from you.