YaRPNcalc is an RPN calculator written in C# targeting the .NET Compact Framework. It's designed for the limited screen size of Pocket PCs. YaRPNcalc is freeware. Its wide range of features inlcude: • Big buttons • Simple to use • RPN input method. Two line visible stack • Basic arithmetic operations • Different display modes (Auto, Fixed, Scientific, Engineering) with possibility to choose number of decimal places • Different bases (Dec, Hex, Oct, Bin) with possibility to choose between 8, 16 and 32 bit 'word size' • Deg and Rad angle modes • The usual stack operations (drop, swap, clear) including undo • Arithmetic functions • Logic functions • Statistics functions • Combinatorics functions • Conversion mode, including user conversions • Constants library, including user constants • Short and long display modes in constant library with possibility to show value • Quick constant and quick conversion function • Colour coding • Stores last settings • Optionally stores the stack • Regional settings aware (decimal point symbol and thousands separator) A powerful and free RPN calculator for Pocket PCs.