Which calculator would you reccomend?

[Vtile]

HP35S is only in current production from HP. HP15C as a original calculator, is smaller much more a pocket calculator, but the HP35S is a bit more modern in its UI and features. That means it can do a few more tricks, by just pressing a few buttons.

If you end up with HP15C, then I personally would go with the SwissMicros clone (the bigger unit) as it do have 1200+ lines of program memory vs. 350 lines in original HP15C, which is a huge difference what you can do with the device. That is if I would pick a 15C which I would not do, while it is a lovely calculator, but the age unfortunately starts to show on it (missing some features and UI is a bit tedious to use, compared ie. from 1980s calcs.). Still a really lovely scientific calculator and really powerfull in right hands and so simple that you can memorise the whole UI and use it with blind eyes.

Personally I would wait and see if the Prime is OK to use.