Why are the HP Prime and HP-35s so unpopular?

[Dave Britten]

(01-24-2021 02:29 PM)aurelio Wrote:  Unpossible to disagreee with you, Max
In the 80's casio sold a lot of calculator with photovoltaic cells, I have still one of that I've used daily on the field (not RPN, sigh, not scientific...) togheter with the 25c and the 41, why HP never tryed to introduce those devices in the best calculators, just a matter of efficiency at that time of the photovoltaic cells, why at least as a backup source?

It's odd that HP never tried including a solar cell on the Voyagers, given how incredibly low their power consumption is. Casio made a few programmable calculators with a solar cell back in the '80s and '90s, though they tend to be fairly limited in their capabilities. The recent fx-50FH and fx-3650PII are probably the most capable, with the former having more memory, but the latter being able to do numeric integrals and derivatives.

Personally, for calculators that need more power than just a coin/button/solar cell, I prefer AAs or AAAs, since I can put in my choice of NiMHs, and know that I won't have any trouble finding fresh ones 10 or 20 years down the road. Or even just grab a pack of alkalines at a gas station or pharmacy if I'm really in a pinch! Kinda why I like the OmniBook 300 too.