Hi!

My wife just (to be honest: it was 10 minutes ago) told me without obvious reason: "You know, what is your most useful gift ever? The hp-calculator! And what else? I wouldn't exchange it for any of your other calculators!"
This is an hp-21s (stat-math) that I bought her for christmas long ago, must have been 1985 or '86, we were still at university then and it was the most expensive one I could afford. She has been using it ever since (over 20 years now, hard to believe how time goes by) and prefers it over Excel when calculating the average marks of her students and for similar tasks that teachers have to do.
By the way: It runs on its second set of batteries, not only voyagers have low power consumtion!

Greetings, Max

I think in the its first decade of use I changed the N cells in my 41CV twice at most. Thereafter, after a period of dormancy, it was malfunctioning and I burned thru several sets of batteries, probably with all of the flicking he power on and off to revive the display (it had broken posts within and the consequent internal contact issues), till FixThatCalc rescued it. Now, I have all of these new peripherals (IR module, thermal printer, wand) that I desired in my youth but couldn't afford. I wonder what the battery life will be like now?

Les

Had to be 1987 or later (the Hp museum states 1998) as the 21s wasn't around before that!

That said, my wife loves her Hp27s and wouldn't swap it for any of the newer trash either (and occasionally, she does look at the newer stuff as well). She has looked at the Ti-83/84 series and is appalled that the solver for the Ti's is so limited in comparison to a supposed much less powerful Hp 27s.

I have a TI83+ and actually have been surprisingly impressed with the speed of the builtin Gauss-Kronrod integrator. Haven't had much occasion to use the solver. How is it limited?

Les