What is a modern-day HP-16C?

[edryer]

There is no modern day HP-16C (the DM16L perhaps if you deny yourself the pleasure of HP's aesthetics and feel).

Whilst many later calculators could emulate the functionality (through obtuse key depressions and functions) often getting to the function required would take longer than actually using it, couple this with no direct (or one step indirect) key-mapping.

I work with the ARM architecture doing a lot of reverse engineering with IDA Pro, and frequently require bit manipulation to check/debug stuff and in this situation far prefer the 16C over both software emulations and other calculators with triple the functionality for well less than half of the price of a used 16C!

Having the physical calculator handy also encourages playing about, testing stuff, and I can say after a few weeks with the 16C it has become very intuitive to use.

Outside of low level code work though it is useless (two transcendental functions), and I switch to a TI-86 (another underrated classic available often for $20 or so) for Matrices and all my Linear work.