Open Source Free Pascal RPN Calculators

TRURL is a suite of desktop calculators with reverse Polish notation (RPN) written in Object Pascal. Additionally, it comes with a free reusable class library (RPN Engine) as a toolbox for creating your own calculator. TRURL is an acronym for "TRURL is a Reusable Universal RPN Library". Class Libraries: • RPN Engine: Full-featured calculation engine for Pascal-based RPN calculators • Segmitator: Library for virtual seven-segment displays Applications: • TRURL A: Simple demo app for the RPN Engine • TRURL B: RPN calculator in the design of the famous calculators by Dieter Rahms for Braun • TRURL G: Desktop RPN calculator inspired by the UI of the DSKY unit of the Apollo Guidance Computer (AGC)

HPN is a functional - as opposed to microcode - cross-platform emulation of a classic 1970s Hewlett-Packard scientific calculator for any command-line interface. Its operations completely model the historical and groundbreaking HP-35 series, and functions to support the HP-45 and the later HP-65, 67 and HP-15C are in the pipeline.