Plus421.3.15 - App Store

Plus42 is an advanced scientific programmable calculator, based on Free42. Free42, in turn, is a complete re-implementation of the HP-42S scientific programmable RPN calculator, which was made from 1988 until 1995 by Hewlett-Packard. Free42 is a complete rewrite and contains no HP code whatsoever.

Plus42 builds on Free42 and adds: Algebraic expressions modeled after those used on the HP-27S and HP-17B/19B; attached units and unit conversions modeled after those used on the HP-48/49/50 series; directories for more organized storage of programs and variables; a larger display, with 8 rows and 22 columns (131x64 pixels) by default, which the user may resize at will; time value of money and amortization schedules; and two-dimensional plotting of functions, with ability to zoom and pan, and find integrals and roots from points in the plot.

Version History Fixed RLN and RRN for negative numbers in BSIGNED mode. 1.3.15 May 5 Fixed crash in REFMOVE.

More accurate GAMMA for integer arguments. 1.3.14 Apr 22 Fixed potential crash in VARMENU. 1.3.13 Jan 14 Fixed crash in menu logic. 1.3.12 10/29/2025 Fixed crash in EQN-> R/S when EQNS does not yet exist.

When a new program was created by inserting END, the new program could end up being locked initially. Fixed. 1.3.11 10/16/2025 Fixed a couple of rare crashes. 1.3.10 07/03/2025 Applying units in PRGM mode didn't work when the RPN stack was empty. Fixed. 1.3.9 06/30/2025 Fixed potential crash on app restart. 1.3.8 06/05/2025 Fix for unreliable state file saving. 1.3.7c 06/04/2025 Now hiding shadowed labels from MVAR catalogs.

Fix for certain rare crashes. 1.3.7a 06/01/2025 Better handling of ACC=0 in INTEG.

More accurate C.E^X-1. 1.3.6 05/21/2025 Fixed a couple of equation editor bugs. 1.3.5 05/13/2025 Fixed handling of shared matrices in PUTMI.

Fixed handling of subnormal complex numbers in 1/X.

Added SLN, SRN, and ASRN to CATALOG-> BASE.

Added current base to the BASE mode status indicators, and made the indicators more compact.

Fixed skin key highlighting for hardware keyboard keystrokes, when using certain skins with complicated key mappings.

Fixed potential crash when loading state. 1.3.4 05/06/2025 BASE menu: Implemented SLN, SRN, and ASRN. These functions are can be typed as Shift-SL, Shift-SR, and Shift-ASR, respectively, and RJ can now be typed as Shift-LJ.

More accurate DET, INVRT, and matrix division for 2x2 matrices.

When spelling out built-in function names, '-' is now accepted as an alternative for '→', to make conversion functions easier to type.

Menu keys that execute different functions when pressed with Shift now show their alternate function while Shift is active. (This behavior can be disabled and enabled using the new STATIC and DYNAMIC settings in the new MENUS submenu of the MODES menu.)

Decimal version: BS→N and BD→N were rounding their results to 16 digits. Fixed. 1.3.3 04/29/2025 (1.3) BASE enhancements: shift and rotate functions, bit manipulation functions, floating-point conversions, and optional digit grouping. See the Free42 web site for all the details.

(1.3.1) BASE: Fixed DECINT behavior for -2^(WSIZE-1).

(1.3.2) RLN, RRN, RLCN, and RRCN did not drop the stack. Fixed.

(1.3.2) Fixed a couple of bugs in the equation editor. 1.3.2 04/25/2025 BASE enhancements: shift and rotate functions, bit manipulation functions, floating-point conversions, and optional digit grouping. See the Free42 web site for all the details.

(1.3.1) BASE: Fixed DECINT behavior for -2^(WSIZE-1). 1.3.1 04/25/2025 BASE enhancements: shift and rotate functions, bit manipulation functions, floating-point conversions, and optional digit grouping. See the Free42 web site for all the details. 1.3 04/24/2025 NEWEQN and EDITEQN functions (EQN.FCN menu). These create or edit equations and strings in place, in the stack and in programs, without needing to go through EQN mode.

Moved equation settings from MODES to EQN.FCN, and moved BASE settings from MODES to BASE, to make them easier to find and to declutter the MODES menu.

(1.2.8a) Fixed pop-up keyboard behavior with dialogs in the equation editor. 1.2.8a 04/19/2025 NEWEQN and EDITEQN functions (EQN.FCN menu). These create or edit equations and strings in place, in the stack and in programs, without needing to go through EQN mode.

Moved equation settings from MODES to EQN.FCN, and moved BASE settings from MODES to BASE, to make them easier to find and to declutter the MODES menu. 1.2.8 04/18/2025 Fixed crash in RCOMPLX/PCOMPLX when the stack is empty (NSTK mode).

More accurate integer powers of complex numbers. Specifically: special cases for pure real, pure imaginary, and numbers of the form a+ai and a-ai.

Fixed VIEW for long values.

Added XSTR option for EQN→STO→X and EQN→STO→PRGM.

The file selector wasn't sorting the directory listing. Fixed. 1.2.7 04/10/2025 Fixed crash when saving an equation without having modified it. This bug was introduced in the previous release.

Improvements in error handling when evaluating equations. 1.2.6 02/19/2025 SOLVER and ∫f(x) now allow selecting programs outside the current directory.

Equation lines were being truncated to a maximum 100 of characters when they were displayed or printed. Fixed.

Implemented Swipe to Delete in the file selector dialog. 1.2.5 02/17/2025 Equations can now be embedded in programs, using X2LINE or EQN→STO→PRGM. Equation lines can be plain, which means they push the equation object onto the stack, or they can be EVAL lines, which evaluate the equation in place. Equation lines can be toggled between plain and EVAL lines using the EVAL function in PRGM mode.

The CUSTOM menu didn't stick reliably, due to a bug introduced in 1.2. Fixed. 1.2.4 02/14/2025 Fixed crash when trying to load invalid skins.

Added IDENT function. This returns the app's version number as a negative integer, in -aabbccdd format, with 1.2.3f formatted as -1020306, for example. The number is negative in order to distinguish Plus42 from Free42, which returns positive numbers from IDENT.

XROMs are now decoded immediately when pasting.

Switched ^ and ↑ in the character set. The change is transparent to the user, but it restores code compatibility with the encoding of ↑ in Free42. 1.2.3 02/08/2025 User-defined units with SI prefixes didn't work in the CUSTOM menu. Fixed. 1.2.2 01/27/2025