HP 19C versus HP 95C

[rprosperi]

I always presumed, perhaps without much thought, that the logic for this was to use the volatile registers as 'workspace' for program variables, and thus typically populated when the program is run (so volatile is OK), while the Continuous registers should be used for storing constants one needs at hand (physics constants that may be unit system dependent, results of some financial calculations or a bank balance, result of a program run, etc.) for arbitrary look-up or to use in a subsequent program run.