My HP-41CX

One of 3 HP calculators I used in college.  This HP-41CX got me through those ugly Chemistry finals when I programmed it with some interactive formulas.  I was actually telling Sam earlier today about RPN logic and its advantages.  I could have shown him in person but I needed some 4 odd-size batteries.  The HP-41C flew on seven Space Shuttle missions and were programmed to recalc reentry in the event of main navigation computer failure.  To think that any cheap game console today has more computing power than this $400 calculator (at the time) is just mindboggling. Even harder to fathom is the fact that I wore this on my belt at school for a couple years.