For consistency with the computer the programmer is working with, the word size can be set to different values from 1 to 64 bits.

The codes displayed while entering the program generally correspond to the keypad row/column coordinates of the keys pressed.

and Royal Consumer Information Products, Inc. introduced the HP-15C Collector's Edition, which comes with an undocumented mode to emulate the HP-16C as well.

The original firmware still had a bug where numbers whose hexadecimal representation ends in E or F are displayed incorrectly in decimal mode, which was fixed by a community effort in October 2023.

Several emulators, including official by HP, are available for desktop computers, web browsers, smartphones and other calculators.

[17] The WRPN Calculator, a public domain open-source HP-16C simulator, is one of the oldest yet active software project of the such type.