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WP 43S Project


A brain storming area for the development of the 43S calculator. Just a collection of ideas and goals for the moment. Everything is subject to change on a whim including the name.


To create the best ever RPN calculator.

  • A feature super set of the HP-42s.
  • A (mostly) feature super set of the WP 34S.


  • Proper alpha keyboard like the 34S or 41C series.
  • Menu based or XEQ alpha based – there will be too many functions for the keyboard. Maybe both menus and XEQ alpha.
  • Typed values like the 42s and later RPL machines.
  • Fully assignable keyboard with the 41C series hold to see function, keep holding to cancel.
  • Less cluttered keyboard than the 34S – fewer shift keys, less overloading and complexity in the keyboard state engine and no hot keys.
  • Dynamic memory allocation.
  • I/O of some kind (serial, USB, SD).
  • Modular software design to allow independent development of (native) functions.
  • A less limited font – sub and superscripts for every available character.

Data Types

  • Reals (decimal or binary or both?)
  • Long reals (again decimal or binary – leaning towards binary here to make use of lots of existing libraries)
  • Integers (binary integers like the 16C/34S or unlimited precisions ones like the 50g or both?)
  • Strings
  • Complex numbers
  • Arrays (at least one and two dimensional, at least real and complex)
  • Fractions (i.e. exact rationals)
  • Intervals (?)
  • Quaternions (?)
  • Units


  • Likely ARM embedded system on a chip based.
  • Lots more memory (flash and RAM) than the 34S (128kb & 2kb respectively).
43s/project.txt · Last modified: 2012/05/14 02:17 by pauli