casio fx-570

here is a classic from the early 80's. by the time this model came out casio had pretty much finalised the content of a scientific calculator; trigs, fractions, stats, physics constants and number bases. also extras like combinations and permutations. it is not programmable as was positioned at a mid price range.

the screen is clear and 10+2 (11 internal digits) and the plastic buttons operate nicely with sensible spacing. the unit is powered by two g12 batteries and comes in the ubiquitous flip over wallet style case.

later remakes like the fx-570d added more constants, a delete key, complex numbers and fancy annunciators, but i still prefer the keys on these older models to the new ones.