Probability (including factorial, random numbers and Gamma function).Statistics (including curve fitting and forecasting).All basic scientific functions (including hyperbolic functions).Peripherals: HP 82240A infrared printer.Expandability: Officially no other than IR printing (32 KB memory upgrade and over-clocking hardware hacks are possible).
![hp 42s rpn scientific calculator hp 42s rpn scientific calculator](https://i.ytimg.com/vi/PUG9olEkXOw/maxresdefault.jpg)
As this calculator is regarded amongst the best ever made in terms of quality, key stroke feel, ease of programming, and daily usability for engineers, in the HP calculator community the 42S has become famous for its high prices in online auctions, up to several times its introduction price, which has created a scarcity for utility end users. Additionally, it features a two-line dot matrix display, which made stack manipulation easier to understand.
![hp 42s rpn scientific calculator hp 42s rpn scientific calculator](https://i.ebayimg.com/images/g/OPsAAOSwp7de-2hu/s-l400.jpg)
The 42S, however, has a much smaller form factor than the 41, and features many more built-in functions, such as a matrix editor, complex number support, an equation solver, user-defined menus, and basic graphing capabilities (the 42S can draw graphs only by programs). Since it lacked expandability, and lacked any real I/O ability, both key features of the HP-41 series, it was marketed as an HP-15C replacement. Perhaps the HP-42S was to be released as a replacement for the aging HP-41 series as it is designed to be compatible with all programs written for the HP-41. 12 display digits (15 digits internally), exponent ±499ģ×1.5V button cell batteries (Panasonic LR44, Duracell PX76A/675A or Energizer 357/303)