Not as much fun as the real thing. I've owned several HP calculators, going back to the 1980s. My 15C might be my favourite, actually, although my 35S is simi

Not as much fun as the real thing. I've owned several HP calculators, going back to the 1980s. My 15C might be my favourite, actually, although my 35S is similarly pleasant to use. Frankly, though, the loveliest were those early-era ones that had rounded backs that were so comfortable to hold and use with just one hand. For me, they are the true classics for use in the lab or the field. I also used a large desktop as a student. It might have been a 9100, but I'm not sure. The keys were great (always a prime aspect of HPs) and it was hooked up to a little plotter that was very handy for seeing what a complicated function looked like. Come to think of it, the only non-HP calculator I ever used was a Sinclair Scientific. It was really fun, but it only lasted a few years before it had electrical problems. But for one-hand use, it was amazing. And it was tiny and weighed very little. It had a sweet little plastic case to protect it, so you could put it in a pants pocket with keys and there was no problem. Good times with RPN.