Not sure who gets this message, but a sad thing happened to me today. My HP12C finally quit. I kinda figured it was coming and was prepared. I had fresh batteries. The first set since it was new. The calculator was purchased in 1985 (Spring) and has never needed replacement batteries. WOW - over 15 ears of pretty heavy use on the same set. Truly amazing even for this great machine.
One of my favorite things about it is watching peers try & use it. Once they learn, they end up with an HP product, but the initial look on their faces is priceless.