Release 0.9.20 "Corpus" - Polynomials and algebraic expressions

This release focuses on support for polynomial, root finding and algebraic expressions, and on making evaluation of algebraic expressions behave closer to algebraic mode on the HP50G, i.e. treat ' like the HP50G treats a backquote expression or an expression entered in algebraic mode.

New features

• LU command generating LU-decomposition for matrices
• REF, RREF and RREFP commands to put matrices in Echelon form
• Order command to reorder variables in the current directory
• PEval, PRoot and Zeros commands for polynomials and expressions
• Unique and QuickUnique commands to keep unique values in a list
• DEPND and INDEP commands to set dependent/independent variables
• Implicitly recognize xlib and constants by name, e.g. c or Dedicace
• Flags to control the above, AutomaticConstants and AutomaticXLibs
• Preserve symbol case for existing variables
• Creating symbols matching builtin names using the Ⓥ prefix, e.g. ⓋHelp
• Value comparison for Sort or Unique now works with expressions
• Simplification now factors common ratios, e.g. A*X+B*X
• Primitive and derivative of a polynomial
• Several new constants lifted from the R47 constant catalog
• Hyperbolic secant functions sech,csch, coth, and their inverse
• CrDir can now take a list as input to create multiple directories

Bug fixes

• Crash in solver in case of error evaluating some intermediate step
• Correctly put parentheses in 'sin(x+1)' rendered in text mode
• Occasional object_error in as_text() on simulator
• Crash in IFT / IFTE if given invalid input
• Detection of expression vs. RPL programs during evaluation
• Crash in quotient or decimal conversions given erroneous input
• Parsing of 0+ⅈ, was incorrectly parsed as 0ⅈ
• Negating 0 no longer shows -0
• No longer allow incorrect mixing of ranges and uncertain numbers
• Dividing a polynomial by a number now divides constant terms
• Correctly split expressions that contain a single term when testing equations
• Fix simulator race condition while loading the keymap
• STO will no longer overwrite a directory with a non-directory value
• Purge will no longer erase non-empty directories, PGDir is now needed
• RAr constant uncertainty was incorrectly set to 0
• Swap keyboard legacy and 42k keymaps in simulator

Improvements

• Purely imaginary values such as 0+3ⅈ now render as 3ⅈ
• The LNAME command now returns a list in algebraic expressions
• Σ, ∏, ∂ and ∫, COMB and PERM now partially evaluate as on HP50G
• Refactor detection of symbolic arguments in functions for scalability
• Refactor detection of algebraic functions for scalability
• Signal when ui_refresh() takes too long due to internal race condition
• Do not drop input in multisolver when a wrong value is given
• Quick exit when parsing empty commands
• Rounding for →ℚ more accurately respects displayed precision
• Internal factoring with square roots and fractions to_sqrt, used in PRoot
• Internal integer and fraction square root, used in simplification
• Reorganize the polynomials menu to bring useful functions at first level
• Accept polynomials and tagged expressions in plotting commands
• Do not default imaginary part to 1 in complex::make (was error prone)
• Optimize the integer power case for range objects
• Zero detection for expressions and polynomials in simplifications
• Makefiles no longer emit confusing mv output in make compare
• New stack_buffer facility in the runtime to keep multiple exansions on stack
• Add ISOL tests for sec, csc, cot functions
• Consolidate project guidance into AGENTS.md
• Simplify simulator beep control logic: -N blocks beeps, -n restores them
• Refresh implementation status
• Update documentation for PGDIR, STO and RCL new capabilties
• Internal facility to swap arbitrary stack levels
• Update man page
• Add recorder_scope-compatible instrumentation for GC and available memory
• Accelerate display of constants/equations/library menus

Release 0.9.19 "Spirit" - More constants, more space left

This release includes a larger-than-usual number of changes, mostly to make room for more constants. A side effect is that we gained a lot of
additional space for the DM42, giving us a lot of headroom for future developments. On the other hand, this may cause unexpected bugs. If
you run DB48x on a DM42, please check for anything out of the ordinary and report it.

New features

• Hierarchical constants library, with astronomy data for planets
• fonts: Add astronomy-related glyphs and a few more
• simulator: RPL evaluation with -e, to preload the calculator
• simulator: RPL console evaluation mode with -E (prints to console)
• simulator: RPL evaluation from file with -f and -F
• simulator: headless mode with -H (no window showing)
• simulator: screen capture with -C for scripting
• simulator: Persist window geometry across runs
• simulator: Persist calculator state on exit
• ui: Enhanced behaviour for EEX key (skips to exponent)
• variables: Store and recall to path
• GCD (GreatestCommonDenominator) and LCM (LeastCommonMultiple)
• Quote command
• Hitting EXIT while editing clears menu

Bug fixes

• variables: Memory corruption when replacing object with subobject
• Fix parsing bug causing partial load of .48k keymaps beyond @
• arrays: Strip tags from array and index in get and put
• solver: Improve solver precision in Std mode
• constants: Correcting the standard uncertainty of several constants.
• constants: Correct the Tau mass relative uncertainty.
• Make sure simulators get the correct help file (distinct .qrc files)
• Show empty menu when entering empty directory in 1-line mode
• Accept decimal / fraction conversions for arrays containing names
• Make it possible to reload Demo.48s after initial run on DM42
• Correctly show error message while loading files
• ui: Do not remove - when using CHS in an expression like 5-3.
• bignum: Remove leftover printf statement
• menu: Refresh CustomMenu if updated while active
• simulator: Fix race condition in Paste command
• ci: keep Android AABs under android/
• ci: package db50x Windows simulator from the correct path
• wasm: bootstrap recorder and host tools correctly
• ci: use libsystre in Windows packaging
• doc: Fix description of simulator -m option
• ids: Fix aliases for EquationValue and XLibValue
• menus: Connect menu entries incorrectly marked as unimplemented
• Fix help topics for various constants / constant groups

Improvements

• fw: Move all C / C++ strings to the QSPI on DM42 (save >80K flash)
• tests: Replace LSHIFT, I with ID_ConstantsMenu for readability
• tests: Run cstlib / eqlib tests beyond first error
• tests: Use STD instead of 12 SIG
• tests: Do not save state file after running the test suite
• Do not waste memory while converting<<, >> and ->
• Improve rebuild in case of QSPI CRC mismatch
• Enable make TAR_EXTRA_FILES= install to install only binaries
• makefile: Generate listing files like the old makefiles
• makefile: Add image comparison targets like in old makefile
• makefile: Avoid extraneous / in paths
• makefile: Pass DB48X_VERSION through the command-line
• debug: Change debug_printf to use all 12 rows
• commands: micro-optimize factorization of cmp == 0 test
• chuck: Make the CHUCK command optional for repeatable builds
• install: Add DISK_NAME variables to specify volume name
• ui: Simplify display of alpha and user indicators
• doc: Add information on how to start Fedora on WSL
• ui: Fix misspelling in comment
• doc: Make the age-verification LEGAL-NOTICE more general
• chore(ci): bump packages versions
• doc: Add Pasquale Pigazzini as an author
• solver: Fix compiler warning about signed vs unsigned
• library: Fix comment and remove duplicate entry
• commands: Add Γ alias for Gamma
• menus: Update and reorganize parts menu
• locals: Detect incorrect argument count in algebraic function calls
• locals: Do not evaluate algebraic expression passed as argument
• version: Update copyright year to 2026
• parser: Accept , as a separator in algebraic function calls
• Reorder the constants menu for efficiency

Release 0.9.18 "Chuck" - Sucess begins inside

This release includes a number of under-the-hood improvements that will make the life of maintainers easier in the long run.

New features

• Implement the Chuck command
• Make xq recognize more patterns during simplification
• List the menus in the help file
• Support for tables in the help file
• Extend re, im, conj and sign to lists and arrays
• Add norm as a separate command from abs
• ListRecursionDepth setting for map, reduce, filter

Bug fixes

• Remove -fsanitize option on macOS (hangs on macOS 26.4)
• Fix incorrect evaluation of constants during simplification

Improvements

• Switch to the make-it-quick build system
• Shared cross-platorm clipboard code
• Automate the build of releases
• Put the variables naming expression patterns in a namespace
• Improved instructions for AI agents
• abs on vectors and matrices now computes absolute value
• Repair GitHub actions
• Improve solver shuffle around singularities and errors
• Fix path for grep testing in case of example test failure

Signed-off-by: Christophe de Dinechin christophe@dinechin.org

Release 0.9.17 - Rational approximation, indexing, Android fixes

This incremental release delivers new features and fixes a number of bugs.

Download assets

New features

• Add →Qπ command for rational approximation with π, √n, ln(n) and e
• Apply →Q and →Qπ to numbers in expressions
• Add array/list indexing support in algebraic expressions e.g. 'L(1)'
• Add ability to Store / Copy to L(1)
• Add "real" ConstantName and ConstantValue commands

Bug fixes

• Fix parentheses around exponents in graph rendering of '(a+b)^(c+d)'
• Fix label for ToRelativeUncertainty, →RelRnd instead of →RelUnc
• Fix command alias mapping for RNrm
• Improve parsing of implicit multiplication for a number of edge cases
• Fix utf8_next for garbage bytes following ASCII characters
• Fix unsatisfied symbol errors with gcc/emcc in the WASM build
• Save Android system state when app is suspended or hidden
• Ensure Android help resources are extracted and available at runtime
• Restore image testing functionality in the test framework
• Updated test images that had become obsolete
• Report errors when saving reference files in tests
• Avoid stack corruption / crash when parsing malformed help index
• Fix computation of DFC(2.3)
• Fix null-pointer crash if the multiple equation solver fails

Enhancements

• Constrain →Q and →Qπ behavior to FIX/SCI/ENG setting (like HPs)
• Minor optimization for program::run
• Save about 3.4K of RAM on physical devices
• Speed up test runs while increasing default wait time for stability
• Documentation cleanup and additions, add more RPL examples
• Add clear build-time error message when a help topic exceeds 80 characters
• Add demo for interactive menu use
• Optimize away redundant argument checking
• Documentation for DCF and DCF2F

Signed-off-by: Christophe de Dinechin christophe@dinechin.org

Release 0.9.16 - Factorization, precision fixes, and documentation

This release adds prime and factorization features, improves numeric precision,
and expands simulator and user documentation.

New features

• Add IsPrime, Factors, PrevPrime and NextPrime commands
• Add MaxFactorsBits and MaxFactorIterations settings for factorization
• Add TRIGSIN command for Pythagorean identity rewrites
• Add a Unix man page and simulator documentation
• Add simulator recorder dump on F16; move demo playback to F13-F15
• Paint navigation arrows in SHOW
• Accept CR/LF line endings when reading Windows files
• Display keyboard access paths in help for commands

Bug fixes

• Fix expm1 precision loss for small arguments, including complex values
• Fix ln1p precision loss for small arguments
• Fix shift behavior after transient alpha, and support shift/xshift for transalpha
• Reset show_x and show_y when exiting SHOW
• Ensure the simulator creates the screens directory when needed
• Fix an infinity optimization regression in arithmetic
• Add missing null-dereference checks in factorization code
• Treat ^ as right-associative like on the HP50G

Enhancements

• Refactor and optimize the decimal factorization code path, with expanded tests
• Add conversion support to float and double in algebraic code
• Update to recorder v1.2.3
• Add documentation updates (DeepWiki reference, legal notice updates)
• Add build preparation for upcoming make-it-quick integration
• Welcome several new authors to the team, see AUTHORS file
• Add LEGAL-NOTICE.md about compliance with California and Colorado laws
• Add menu entries for hypot and atan2

Signed-off-by: Christophe de Dinechin christophe@dinechin.org

Release 0.9.15 "Myriam" - GitHub automation, portability

This release focused on GitHub and GitLab automation, and provides automated macOS, Linux, Windows and Android builds. You can still download the artefacts the usual way, but there should be new links attached to the release as well with artefacts generated through this new GitHub workflow.

New features

• GitHub automation automatically builds various packages
• Preparation for GitLab automation (still largely untested)
• Windows simulator
• Android package
• WebAssembly application (WASM) now has help and configuration files
• DM42n build (differs from DM32 only in the help files)
• Dockerfile to create a container with the simulator
• Add ρ in RangesMenu
• Accept units when creating a range from components
• Add Range→ command that expands ranges with units

Bug fixes

• Corrected typos in some builtin constants
• Spelling and grammar fixes in documentation
• Build failure for wasm due to use of source, a bash-only syntax
• WebAssembly application no longer uses 100% CPU
• The simulator can now be launched from any directory
• The macOS simulator correctly launches from the Finder or Dock
• Portability bug fixes in the DMCP emulation
• The Settings menu is now correctly refreshed after ResetModes
• Fix double-shifted arrow keys
• Correctly show help for Swap, Negate, and Cycle
• Fix order on stack for Explode on a range value
• Android build bug fixes

Enhancements

• Add osx program in lauch.json
• The simulator no longer overwrites configuration files by default
• Builds that use gcc now enable more warnings
• Simplify shift-handling logic

Release 0.9.14 "Latran" - Android preparation

This is a very minor release with bug fixes notably for Android

New features

• The screen updates when rendering and PICT is set

Bug fixes

• Wait for durations longer than 1 second now works in simulator
• →%Range, →∆Range and Range→ now use displayed values
• 0.9.13 regression, leftover input value after error during plotting

Improvements

• Semi-working Android build

Release 0.9.13 "Saints" - Truth plot, colors, and bug fixes

This release focuses on graphics and a few user-reported bug fixes

New features

• bins computes frequency bins from statistics data
• Res sets the resolution when plotting
• HistogramPlot draws a histogram (frequency) plot from an array
• HSV generates a color pattern from hue, saturation and value
• Color generates a color pattern from an object, including names
• TruthPlot renders a truth value plot, with grayscale and color options
• Add a new XYPlots demo illustrating TruthPlot variants

Bug fixes

• Update the screen in Show when Pict is set
• Fix crash in Date+ when adding invalid dates
• Correctly update the UserModeMenu and annunciator when changing User mode
• The STO operation now works sensibly on flags
• Fixed a rare on-startup crash running tests in the debugger
• Invalidate the font cache when changing settings (notably FixedWidthDigits)
• Fix transient Input validation errors after text-editor errors
• Remove two extra parentheses in the documentation for settings

Improvements

• Transient Alpha now preserves existing Alpha / Lowercase mode
• Remove dependency on external crc32 utility, now use a local implementation
• Remove dependency on tac, replace it with tail -r
• Rendered graphics are now preserved in case of auto-power-off
• Avoid transient build errors on missing help directory
• Add documentation for ResetModes and usage example for Modes
• Negative dates now show as BC instead of with a minus sign

Release 0.9.12 "Alive" - Return to active duty

This release focuses on simulator improvements, bug fixes, and enhanced mathematical functionality, marking a return to active development and maintenance after the hiatus caused by Christophe de Dinechin's move.

New features

• Enhanced trigonometric functions with exact angle reduction when possible
• Improved simulator graphics by smoothing the output when rescaling

Bug fixes

• Compute Julian day number conversion with negative Gregorian years
• Fixed crash in lgamma function on DM32 / DM42n platforms
• Fixed undefined symbol issue in WASM builds
• Fixed platform-specific compilation errors on Android
• Fixed incorrect simplification for sqrt function
• Fixed display of checksum in the Info box
• Fixed hang when reading CSV files containing unit objects
• Do not reorder mean and standard deviation parts in uncertain numbers
• Avoid possible null-dereference in several statistical functions

Improvements

• The simulator now preserves a fixed aspect ratio while resizing
• The simulator now builds cleanly on Qt5
• Added 2 new tests for Julian day number conversion
• Updated copyright year in About message
• Improved description of "Julian day number" commands in documentation
• Improved build system to select qmake6 on Arch Linux
• Show →Num spelling in compatibility mode
• Updated AUTHORS list
• Remove documentation for newRPL commands UDEFINE and UPURGE
• Improve implementation status section of the documentation

Release 0.9.11 "Prayer" - Uncertain numbers

This release implements arithmetic and basic functions on uncertain numbers.
This propagates uncertainty using quadradic superposition, in a way similar to OpenRPNCalc, with a generalization for correlated variables.

New features

• Arithmetic and basic functions on uncertain numbers
• Add support for complex-valued unit objects, e.g. 5+3ⅈ Ω
• Add support for range-valued unit objects, e.g. 1…3 Ω
• Support arithmetic operation on infinities, e.g. ∞ 42 +
• Add commands to generate mathematical constants (π, ℮, ∞ and −∞)
• Parsing and editing of ranges containing infinities
• Accept infinities in →Range and variants
• Comparison of infinite values and finite values
• Add union and intersection commands for ranges
• Add operations to build ranges and uncertain numbers from components
• Add derivative for erf and erfc

Bug fixes

• Do not leave bad expressions behind after errors on ranges
• Obey the InfinityError flag when detecting divide-by-zero in ranges
• Avoid crash pushing null pointer after unit evaluation error
• Avoid spurious inconsistent units error due to date computations
• Null-protection in variadic list::make, fixes null-deref crash

Improvements

• Accelerate error exit from arithmetic operations
• Render uncertain numbers as 110±σ15 instead of 110±15σ
• Accept − as valid input in constants (for −∞)
• Record performance data for iPhone 16
• Change spelling to →σRange in RangeMenu
• Use ASSERT for divide by zero inner checks (remove dead code)