5-ReleaseNotes.md

Release notes

Release 0.9.3 "Transfigured" - Documentation, bug fixes

This release keeps improving the documentation based on the original HP50G Advanced Reference Manual, and fixing issues that are found along the way. It also improves statistics support and adds low-level array manipulation.

New features

• Add PredX, PredY and ΣLine commands for linear regression predictions. The PredX command predicts the independent value from the dependent one. The PredY command predicts the dependent value from the independent one. The ΣLine command returns the regression formula.
• Add Median command to compute the median of statistics series
• Add low-level array manipulation commands, COL+, COL-, ROW+, ROW-, CSWP and RSWP, to add, remove and swap rows or columns.

Bug fixes

• Strip trailing zeros from decimals converted from integers, in order to avoid producing incorrectly normalized values. For example, 70000 converted to decimal now produces a 5-bytes decimal value and no longer a 6-bytes decimal value. This fixes the result of the SigDig command on this input value, as well as fixes cases where comparisions would be incorrect.
• Accept quoted names in == and same. HP calculators evaluate A and B in 'A' 'B' == but not in 'A' 'B' same.
• Add symbolic support for logical operations, i.e. correctly create an expression for 'X' 3 and instead of a type error.
• Compute linear regression for each mode when running BestFit. The previous implementation would erroneously compute the correlation with various modes (linear, log, exp and power), but without optimally recomputing the parameters with that mode.
• Consume arguments in XCol, YCol and ColΣ
• Write slope and intercept in the correct order when updating ΣPar. The order was wrong, causing various commands to either update them in the wrong order, or to swap them.
• Do not emit an error if the stack is empty when running Σ-
• Fix and optimize parsing of ==
• Fix a bug in decimal comparisions used by sqrt and cbrt, fixes the computation of the last digits of sqrt(163) at 24-digit precision.
• Compute log with 3 additional digits to avoid getting the last digit wrong in 'ln(640320^3+744)/sqrt(163)'
• Compute exp, exp10, log and log10 with additional internal digits to make sure that the last digit is good (verifiied using calc).
• Fix sign error in buoyancy equation for Champagne bubbles
• Fix ppar parsing and premature validty checking, which caused 20 30 XRNG to fail because of a transient state where xmin<xmax was not verified.
• expression: Fix rare GC bug in expression::simplify

Improvements

• Compute all decimal functions with increased precision. The tests now check that the last digit of the functions result for the tested input is correctly rounded.
• Add type value for xlib objects in HP compatibility mode
• Add TruthLogicForIntegers flag for compatibility with HP calculators when evaluating something like 42 and 4. DB48x by default computes this bitwise, which returns 0, a logically False value. With the new compatibility flag, the arguments are interpreted as truth values, and the computation produces True for improved compatibility with HP calculators.
• Add RPL programming examples in the documentation, lifted from the HP50G Advanced Reference Manual, covering conditional statements such asIF, IFT, IFTE, documentation about tests and conditional structures, type tests, logical commands such as and, or, not.
• Add documentation and menu entry for Header command
• Add documentation about local variables and the scope of local variables
• Add tests for statistics operations
• Optimize retention of slope and intercept in BestFit
• Micro-optimization on stack operation for comparisons
• Add MSolvr alias for SolverMenu for compatibility with HP calculators
• Allow nested precision adjustments in decimal::precision_adjust class
• Tests now display failures in a way that makes it easier to compare.
• Add documentation for SeparatorModesMenu entries
• runtime: Add check that we push only valid objects
• runtime: Cleanup, remove leftovers from earlier debug
• runtime: Add check for pointer validity
• runtime: Add utility to dump GC pointers
• arithmeric: Add recorder entry to record what operations happen
• Update copyright year to 2025 in VERSION command

Release 0.9.2 "Temptations" - Multi-variate solver, documentation

This release introduces a true multiple-variables solver, additional matrix operations, and extends the RPL programming documentation.

New features

• The Root command now selects a true multi-variable solver (Jacobian solver), capable of solving systems of equations with multiple variables, even when variables cannot be isolated one at a time, for example solving { 'sin(x)=y' 'sin(y)=x+1' }. As a result, the DB48x Root command now covers the functionality provided by the HP50G's ROOT, MROOT and MSLV .
• Compatibility for MSLV is preserved thanks to a dedicated command, which like the HP50G leaves input equations and variables on the stack.
• Add RNRM and CNRM (row and column norms) commands for matrices.
• Add TRN and TRAN commands (matrix transpose, with or without conjugate)

Bug fixes

• Add several missing images used by the test suite to the git repository, e.g. for the TVM menu.
• Fix rare bug parsing lists causing a validation error
• Fix theoretical risk of memory corruption in det
• Solutions found by the solver no longer depend on the existence and value of global variables by the same name prior to solving
• Emit "Interrupted" error when interrupting the solver
• Fix bug comparing decimal zero with small decimal values

Improvements

• Add a section with RPL programming examples, seeded with examples from Chapter 1 of the HP50G Advanced Reference Manual.
• Add documentation about program objects, text, symbols and comments.
• Update documentation for complex numbers, e.g. ℝ→ℂ command.
• Add documentation for abs
• Add links to "Rules" in constant uncertainty section
• Add a few additional tests in the documentation
• Split instrumentation for the three solver algorithms.
• The solver now uses the display precision to limit the precision of the desired result, like the integrator and like HP calculators.

Release 0.9.1 "Follow" - Finances, bit-counting and constants

This release follows-up on 0.9.0 by improving the way constants are evaluated to better serve the equation library. It also adds finance-related functions, and specialized bit-counting functions.

New features

• Add standard and relative uncertainty for all constants. For a constant like G, which when edited looks like ⒸG, the standard uncertainty is ⓈG and the relative uncertainty is ⓇG. This shows as UsG and UrG on screen, to match common practice.

• The constants menu now contains helpers to enter constants, and for the commands Const, StdUnc and RelUnc, which generate a constant, a standard uncertainty or a relative uncertainty from a name.

• Implement precision-control functions that make it possible to adjust the result of computatoins adjusting to relative or standard uncertainty. →Us and →Ur convert betwen standard and relative uncertainty. StandardRound, RelativeRound and PrecisionRound round a value based on its standard or relative uncertainty, or according to the precision of some other value.

• Add bit-counting operations. FirstBitSet and LastBitSet find the position of the first and last bit set in an integer value. CountBits counts the number of bits set in an integer value.

• Add finance operations. The finance menu TVM now shows a solver for time value of money, with payments at beginning (TVMBeg) or at end (TVMEnd). The Amort command generates the amortization (principal, interest and balance). The AmortTable, a DB48x extension, generates a complete amortization table. A new setting, FinanceRounding, a DB48x extension, sets the rounding of finance results.

• Add the Sub command to extract a subset of texts, lists or grobs. As an illustration, the Anagram program was added to the demo state. As a side effect, the named variants for arithmetic operators have been renamed from sub, mul and div to subtract, multiply and divide.

Bug fixes

• Avoid possible crash when using the delete key while searching.

• Fix a few broken (obsolete) links in the help file.

• UVal now works on numbers, not just on unit objects, like on HP calculators.

• Remove NewRPL names for some commands like ToRectangular, and replace them with the DB48x spelling.

Improvements

• Constants are brought up to date to the latest best practice from the scientific community. This includes computing many derived constants from a smaller subset of exact constants, as well as providing standard and relative uncertainty for each constant.

• Constant values are cached to accelerate their evaluation. This avoids having to parse and evalute constant definitions.

• The ConstantMenus was reorganized with more constant categories covering dates, mathematics, chemistry, phsyics, particle masses, electromagnetism, atomic sizes, Compton scattering, magnetism, materials and computing.

• The MathMenu was reorganized, notably to make the exp and log functions easier to access. This merges the former PowerMenu and ExpLogMenu so that the MathMenu still has less than 18 entries.

• Numerical integration now uses the refinements documented in Kahan's 1980 HP Journal article about numerical integration on the HP34. This makes it possible for example to integrate 'sin(x)/x' over 0 to π interval.

• Numerical integration now limits its precision to the number of digits being displayed, like on HP calculators.

• Document the difference and rationale for parsing quoted names compared to HP calculators.

Release 0.9.0 "Wilson's Dream" - Full equation library

This version integrates an extended version of the HP50G equation library that Jean Wilson has been working on for many weeks. Equations are also fully documented, with examples illustrating how to use them, and a full documentation of the variables they contain.

It also fully enables the algebraic-assisted solver, i.e. a version of the solver that attempts to isolate variables to evaluate expressions directly, which is both faster and more accurate when possible.

WARNING Equations in the current state of the library are not fully validated yet. DB48x users are invited to test them and report issues they find.

WARNING Constants used in the library are relatively accurate and have been modernized compared to the HP50G version. However, an effort is underway to compute the physical constants that are not fundamental but derived from other constants. It is expected that the numerical values returned from the equations will changeslightly as constants are udpated.

Features

• Improved equation library and documentation The equation library now features more than 650 equations, more than 700 variables, 18 sections and 158 subsections. This is roughtly twice as big as the HP50G equation library, and covers more modern aspects of science such as nuclear physics.

Bug fixes

• solver: Do not propagate errors during isolate When using the algebraic-assisted solver, errors raised by the internal calls to isolate no longer manifest as solver errors.
• units: Do not leave error behind in unit::convert_to_real This could cause spurious Inconsistent units errors while solving.
• logical: Make logical operations behave symmetrically, i.e. ensure that #100+1 and 1+#100 both return #101.
• nfunctions: Evaluate symbolic arguments symbolically and fix bugs converting arguments to decimal. The evaluation of '∫(0;1;x+1;x)' after x=3 would result in a nonsensical expression '∫(0;1;4;3)'.
• integrate: Report errors in bound evaluation. An error in the evaluation of the first bound could be "erased" if the evaluation of the second bound was successful. For example, in '∫(0;1;sin(x)/x;x)', the Divide by zero error evaluating 'sin(x)/x' at x=0 is erased by the successful evaluation at x=1 that follows.

Improvements

• equations: Accept units in isolate This allows many equations in the equation library to successfully use the symbolic approach, improving accuracy significantly.
• add/sub: Accept zero as an operand around units. An operation like 1_km+0 is now accepted, and evaluates as 1_km.

Release 0.8.11 "Accomplishment" - Towards full equation library

This release contains a number of fixes and features intended for use in the equation library being contributed by Jean Wilson

Features

• Accept library items for functionc calls. For example, the expression 'ⓁSiDensity(273_K)' is now accepted. This function is usd in semi-conductor equations in the library.
• The Root command now attempts symbolic solving using the Isol command. This can lead to exact solutions for common equations.
• The SigDig command is a DB48x extension that returns the number of significant digits in a number, i.e. the number of non-zero digits.
• The xpon and mant now apply to unit objects
• Functions now accept assignments as input, e.g. x=9 sqrt gives 3.0
• The equation referenced to by the Equation variable can now be identified using a name.
• The NxEq command now works with quoted equations

Bug fixes

• The ln(1E-100) expression no longer gives a Argument outside domain error. The error was caused by rouding during argument reduction.
• Comparison between a value and a unit object now work correclty
• Arithmetic now correctly deals with dimensionless unit objects, for example in expression '1-1000_mm/m', and improves the evaluation of unit expressions when adding or subtracting unit objects.
• Names containing programs or functions are now evaluated as part of algebraic evaluation
• The solver now correctly processes equations wrapped in an expression.
• Convert now correclty evaluates its arguments when necessary
• Assignment objects no longer cause a crash on error. For example, x='ln(0)' no longer crashes.

Improvements

• Improve solver heuristic when slope is small. This allows the solver to find a solution for an equation like 'tan(x)=224' in degrees mode.
• Add more recorder entries in the solver describing what is being solved.
• Move recorder entries for tests to tests data logger.
• Tests use a larger text rendering limit
• Tests now purge the directory between examples. This prevents stray variables from influencing later tests.
• The handling of long UTF-8 sequences in tests was improved, which allows tests involving a lot of text (e.g. examples) to run faster.

Release 0.8.10 "Fire Dove" - Input and Prompt, Android preparation

The focus of this release is support for user input in programs, with the addition of the Input and Prompt commands. Internally, a lot of groundwork was performed towards Android builds.

New features

• Add Prompt command, which programs can use to let users manipulate the stack or do other operations before resuming execution.

• In order to facilitate the use of Prompt, added the Run command, which resumes execution of halted programs and otherwise evaluates the first item on the stack. The key at the left of the + key, which is labeled R/S on the DM-42 calculators, is now bound to the Run command instead of Evaluate. Therefore, after a Prompt, you can resume execution with a single key.

• Add Input command, which programs can use to let users enter data. The DB48x version makes it easier to enter and validate numerical data or other non-text objects, with input validators for numbers, integer values, arithmetic objects or expressions. It is also possible to use custom code to validate user input.

• Additional Compile variants were created to help with this user input validation, checking if the input is a number, an integer, a positive integer, a real number, a single object, a single algebraic object or an expression.

Bug fixes

• Fixed problem with the computation of the length of the integer value being parsed if it was parsed from a text value at the end of the temporaries.

• Emit an error from Step and variants if no program is being debugged. The effect was that the next program being run would halt after the first step.

• Avoid persisting beep in the simulator when two beeps were emitted rapidly in successioon.

• Reload the user-selected keymap file after loading the state file.

Improvements

• Change capitalization of DTag as a shortcut for DeleteTag.

• Various code improvements making it easier to compile for Android. A side effect is that the simulator can now safely be started from any current directory.

• Improve rescaling of the window in the simulator to keep the keyboard and screen larger and easier to read.

• Improve the detection of the default simulator size for Hi-DPI screens.

• Add documentation about matrix multiplication performance

• Make the default memory size more consistent with the simulated device.

Release 0.8.9 "Advent" - Mostly bug fixes

This is a relatively minor release, with mostly bug fixes, but also a new, explicit syntax for hardware-accelerated floating-point.

New features

• Hardware-accelerated IEEE-754 binary floating-point values are now identified with a suffix, D for double (64-bit), F for float (32-bit). For example, 1.23 is a variable-precision decimal value, 1.23D is a 64-bit binary floating-point value, and 1.23F is a 32-bit binary floating-point value. This ensures that the HardwareFloatingPoint setting does not change the way a program is compiled or presented, only its computations.
• plot: Draw a bar on the horizontal axis for errors. This makes it easier to identify where the function is not defined.
• probabilities: Extend COMB and PERM to real arguments For real argument, the Gamma function extension of the factorial is used with the usual expressions to compute combinations and permutations. One user remarked that some half-integer combinations of arguments, for example, directly give some common Taylor series factors with a single expression.
• decimal: Add decimal to integer conversion (R→I)
• simulator: Add -N option to disable sound. This is notably useful on Linux where some hardware platforms takes tens of seconds to fail, slowing down error messages.
• simulator: Recognize settings on the command line. For example, you can enable the silent beep feature (flashing screen on error) by passing the SilentBeepOn=true parameter on the command-line.
• parser: Add PREC alias for Precision.

Bug fixes

• random: Fix bias in integer version of Random. Using 1 10 Random would generate values 1 and 2 at half the frequency of other values.
• help: Do not process links that are not visible. This could cause links that had scrolled past the top of the screen to be incorrectly selected when pressing the ENTER key, even if there was an RPL code example visible on the screen.
• simplifications: Do not simplify infinities. Earlier versions would incorrectly apply a rule like X-X=0 to the case where X was an infinity, giving incorrect results. This could manifest for example in Comb with decimal input returning 1 for large values (as a result of dividing ∞ by ∞) and Det returning 0 (as a result of subtracting ∞ from ∞).
• expression: Fix rendering of derivative, primitive and where in HP compatibility mode. This could cause programs to become unparseable, e.g. with ∂X(X+1) turning into DERIVATIVEX(X+1).
• expression: Do not render arity-2 commands as infix. For example, CONVERT(X;1_m/s) no longer renders as X CONVERT 1_m/s.
• simulator: Improve extension checks on case-independent filesystems. On such systems, files foo.48s and FOO.48S are identical. The simulator could incorrectly add a second extension if the case did not match.
• arcsin: Fix the incorrect computation of arcsin(1). More generally, improve the way exact angles are generated by functions that require them. This allows such functions to now return non-rounded results when using angle modes such as degrees. Previously, a computation involving the value of the π constant would cause some rounding even if an exact result was possible.
• Fix a rare bug in the user interface which could lead to memory corruption if a garbage collection happened at the wrong time.
• Accelerated arithmetic evaluation is now correctly disabled when the HardwareFloatingPoint setting changes.
• Fix silent errors when NumericalResults is on and computations involve non-normal results (e.g. infinities).
• Convert infinities correctly from hardware floating-point to decimal.

Improvements

• simulator: Return relative paths when selecting files when possible. For example, when selecting the name of a keyboard layout, a file is written on disk that used to contain the absolute path of the layout file being used. As a result, moving the simulator directory elsewhere would make the file unreadable.
• files: Automate tracking of open files. A mechanism was implemented in earlier releases to avoid opening two files at the same time, because that is a limitation of the DMCP implementation on SwissMicros calculators. That mechanism required manual maintenance by developers, and was the source of many bugs. A new mechanism replaces it that transparently manages scenarios where multiple files are open simultaneously. This should quash annoying bugs, such as one where the simulator would write state files with incorrect spelling for constants or library items.
• doc: Remove the docol.md section of the help. This file was inherited from newRPL documentation, and incorrectly documented existing DB48x functions, or mentioned functions that do not exist on DB48x.
• grob: Accept BMP files with zero colours. Some contributors have submitted files generated by Windows tools that describe the BMP file as a bitmap with 0 colours instead of 2. These files were not loading in the helpfile. They are now read and displayed correctly.
• Hardware-accelerated floating-point arithmetic now also benefits from the accelerated dynamic dispatch.

Release 0.8.8 "Voice" - Power usage reduction

This release focuses on reducing power usage and improving reactivity, notably while running on battery.

Features

• Cache rendered graphics and text on the stack to reduce the time spent redrawing the stack.

• Limit the size of objects being rendered on the stack. Objects that are too large will simply render as something like Large bignum (399 bytes) on the stack. This is configured by two new settings, TextRenderingSizeLimit and GraphRenderingSizeLimit.

• Limit the size spent rendering graphical objects. There are four settings controlling the maximum time spent rendering objects graphically. ResultGraphingSizeLimits controls the display for the first level on the stack, StackGraphingSizeLimit controls the display for the other levels on the stack, ShowTimeLimit controls the display for the Show command, and GraphingTimeLimit controls other graphical rendering.

• Blink the battery icon when in a low-battery situation.

• Add configurable MinimumBatteryVoltage to adjust the threshold for low-battery detection and automatic power-off.

• Power-related commands: The BatteryVoltage and PowerVoltage read the battery and power voltage respectively. The USBPowered commands detects if the calculator is running on USB power. The LowBattery command detects if the calculator is running low on battery.

• Detect and reject Unicode characters that look like mathematical characters, and are produced by auto-correction on Windows, notably the- and * signs that look like - and *. This is notably useful when copy-pasting in the simulator on Windows.

Bug fixes

• Fix NDupN again. While the previous release fixed what NDupN does, it did not fix the detection of the number of arguments, meaning that NDupN would incorrectly complain about missing arguments if the stack was not deep enough.

• Fix the precedence of unary - when in front of a parenthesized expression. For example, -(X)^2 now parses correctly.

• Disable keyboard repeat timer when no key is pressed. It was possible to trigger a condition where the keyboard repeat timer would trigger continuously if two keys had been pressed in rapid succession, keeping the CPU in a busy loop and depleting the battery unnecessarily rapidly until another key was pressed. This could also trigger incorrect long-press detections, e.g. the shift key triggering alpha mode instead of a simple shift.

• Disable all timers when switching the calculator off. In some situations, the display refresh timer could still remain active after the calcualtor had been switched off.

• RclΣ now returns the statistics data even when the ΣData variable contains the name of a variable or file.

• The Off command can now be used while editing and no longer causes immediate command-line evaluation.

• Return to the first page of the catalog menus when updating it, to avoid scenarios where the catalog appeared empty

• Return to the first page of the cartalog menu when changing directories, to avoid showing an empty variables menu in a non-empty directory.

• Do not leave garbage on the stack after failed array arithmetic.

• Avoid occasional test crashes due to concurrent pixmap updates in the simulator.

• Avoid occasional spurious error on Primitive test due to long execution time.

• Switch to kg as the base unit for UBASE instead of g, following the SI standard.

Improvements

• Reduce animations more drastically while on battery power. Notably, the cursor does not blink, and menu animations are entirely disabled.

• Rework the animation and screen refresh system to make it easier to maintain and more power-efficient while on battery.

• Refresh the display using hardware-accelerated background refresh routines provided by the DMCP platform. This can be disabled using the SoftwareDisplayRefresh flag.

• Redraw the battery immediately on power change, i.e. plugging or unplugging the USB cable.

• Updated built-in constants with latets CODATA values (contributed by Jean Wilson)

Release 0.8.7 "Signs" - Performance optimizations

This release focuses on performance improvements and bug fixes for issues reported by users and contributors.

Features

• Long array operations such as matrix multiplications can now be interrupted with the EXIT key.

• Eliminate local names from LNAME output. For example, if you perform a sum with a variable named i as an index, no longer report i as being a name used by the expression..

• Implement HEAD and TAIL for text objects.

• Allow constant definitions to contain expressions, which will be fully evaluated when using the →Num. This makes it possible to now define constants using other constants, in the spirit of the more recent CODATA recommandations.

• Library management commands Attach, Detach and Libs are now implemented. These commands make it possible to reload a library entry after changing its definition on disk. While they take arguments that are similar to what HP calculators do, they are not interpreting them in the same way due to hardware differences between SwissMicros and HP calculators.

Bug fixes

• Fix hard crash when running some RPL programs using conditional loops, local variables and/or deep recursion. The crash was caused by a non-robust check of whether the call stack needed to grow or shrink, which was replaced with a much more robust check.

• Fixed the precedence of the unary - operator, so that -X^2 now parses correctly (it used to be interpretd as (-X)^2)

• Fix a crash where an error during an array operation could cause a null pointer to be pushed on the stack.

• The test suite now correctly reports error detected while checking the examples in the online help.

• The multi-solver no longer considers the index variable in a sum or product as a variable to solve for. This avoids spurious errors claiming that a solution cannot be found. The same also applies other functions that take a variable name as an argument, such as Root, Integrate or Isolate.

• Fix a crash when comparing unit objects that cannot be converted from one to the other, e.g. comparing 1_m and 1_h.

• Fix the order of commands in the build instructions for Windows.

• Fix the NDupN command to duplicate an object N times. In earlier releases, it was incorrectly duplicating N objects and leaving N on the stack.

• Accept addition and subtraction between a number and a unit object where the unit can be reduced to a number, so that '1+1_km/m' is now a valid expression. A few additional entries in the equation library now work thanks to that fix.

• Avoid a rare crash where the error command would be corrupted when cleaning temporaries.

Improvements

• Performance optimizations for decimal arithmetic, using 25x25 matrix multiplication as a test scenario to optimize. The performance of such multiplication was improved by about one order of magnitude, and is now comparable to DM42 performance. This was achieved in particular by making more aggressive cleanup of temporaries, by reducing the need for garbage collection, by adding a fast-tracked path for arithmetic operations when the types are the same as for the last operation, and by deferring the construction of arrays until the value of all elements are computed.

• Add a few new sanity checks for the runtime when running on the simulator, notably to detect cases where the internal pointers are not in the expected order, and to more precisely report issues if integrity checks fail during garbage collection

• Add locking to the garbage collected pointers list when running on the simulator, in order to improve test stability. Testing on the simulator is the one case where multiple threads may concurently access the pointers list.

• Accelerate the tests that insert large amounts of text from source code, notably the equation parsing tests and the help examples checks. In addition, use a smarter method to insert RPL separators such as [] or '', taking advantage of the fact that they are usually entered in pairs. These two improvements reduce the total runtime of the entire test suite by a factor of more than 4.

• While testing the online help examples, only report the exact section title and not all the section titles that contain the same text.

• Systematically strip tags and assignment objects for all arithmetic operations.

• Add a version of the debug_printf that automatically selects where to draw on the screen, and automatically clear what follows the printed text using a gray pattern.

• Render the DB48x TrueType font to bitmap using a more recent version of the FreeType library. This causes minor glyph differences compared to earlier releases. The test suite was adjusted accordingly.

• Remove some of the leftover references to newRPL commands that will not be implemented or make no sense for DB48x. This work is not finished yet. The mechanism to remember which command caused a particular error was also made somewhat more efficient.

• Consolidate the two distinct documentations of the Root command.

Release 0.8.6 "Daniel" - Bug fixes and optimizations

This release is mostly intended to fix a number of issues reported by users or discovered during testing.

Features

• Fancy digits are now accepted for decimal and based numbers. This means that 1.⁳³² is now a valid input to Str→, ensuring that we can parse the output of →Str if it uses fancy characters, or that copy-paste works from the stack to the editor.
• Accept array arguments for min and max, applied element-wise in the same way as addition for example.
• Add CompatibleBasedNumbers setting to render 16#AB as #ABh like HP calculators.
• Improve protection against mismatched QSPI and PGM. Only binaries issued from the same build are now accepted. This is mostly of interest to developers, although releases that are very close to one another, like v0.8.4 and v0.8.5 were, can require this protection.
• On DM32, numbers with an explicit numerical base keep that base if it's 16, 10, 8 or 2. For example, 10#200 and #200₁₀ will display in base 10 irrespective of the Base setting, just like #200d.
• Add ϵ character (Greek Lunate epsilon), which appears in some equations.
• Add text alignment options to DrawText, making it possible to align text horizontally or vertically. See examples at end of the Texts program in Demo.48s
• Add UnitsSIPrefixCycle command to set the variable with the same name to customize SI prefixes cycling for units on the command-line. After "KMG" UnitsSIPrefixCycle, typing the Cycle key (_×10ⁿ or EEX) with 1_B will cycle through 1_KB, 1_MB, 1_GB and back to 1_B.
• Accept u as an alternative SI prefix for "micro-", e.g. 1_us. This is intended to allow entering of the "micro" prefix using transient alpha mode.
• Add help lookup for solver variables. When in the SolverMenu, holding the function key for a vairable brings up the help for the corresponding variable in the equations library.
• Add SiDensity (SIDENS on HP) and Fanning functions to the library. These functions are used by some equations in the library.
• Add invert alias for 1/x operation (like negate for neg).

Bug fixes

• Fix unit scale cycling for multi-character units
• Fix incorrect computation of output matrix size for non-square matrices. [[1 2]][[3 4]] + now works.
• Negation on based numbers and polynomials now works.
• Conversion of decimal values smaller than 1.0 to integer no longer crashes (this could only happen with the RanM command)
• Render - for first term of polynonials if negative
• On DM42, update the bases menu when cycling based numbers
• Fix parameter mixup for call to program::run. In theory, this could lead to programs not evaluating correctly if NoLastArguments setting was set, although another bug apparently made this very unlikely to be observed.
• Update index footer to point to https://48calc.org instead of obsolete https://github.io location.
• Updating a for loop variable from within the loop now behaves like on HP calculators, and can be used to control loop exit.
• Do not draw activity indicator in graphical mode. This was a regression introduced with BusyIndicatorRefresh.
• Mark xroot command as implemented in the PowersMenu
• Use consistent case for variable x in the equations library
• Do not error out comparing text values
• doc: Fix typo latter -> letter

Improvements

• Add auto-cleaner optimizations for matrix and vector operations. This reduces the memory usage and frequency of garbage collections.
• Reduce random bias for integer input, e.g. -10 10 random no longer has a +0.5 bias on average.
• doc: Several updates and fixes to the documentation, notably with respect to the description of the current status, and instructions for Windows developers.
• Add →Prg alias for →Program
• Add the simulator minimum window size
• Add rmdir as an alias for pgdir. "This is Unix".
• Add L (uppercase) spelling for "liter" unit
• doc: Avoid overlapping aliases in Rcl/ help text by adding some aditional text to the Rcl* help.
• doc: Add documentation for SolverMenuSolve and SolverMenuRecall
• doc: Fix documentation for AssignKey
• doc: Add documentation for comparisons
• doc: Remove duplicate dup
• doc: Update documentation about add
• doc: Refer to CharactersMenu and Catalog in alpha overview
• doc: Update keyboard sequences typography
• doc: Remove false claim that interactive stack is not implemented
• doc: Update implemented / unimplemented list

Release 0.8.5 "Stone" - Emergency keyboard fixups

The major changes in 0.8.4 caused some damage to keyboard handling code that require a few emergency fixes.

Bug fixes

• Fix incorrect selection of lowercase characters

• Fix the location of exp and log10 in 42style and true42 keymaps.

• Do not enter interactive stack if reaching leftmost position of the text editor.

Release 0.8.4 "Commands" - Optimizations and equation fixups

This release focuses on improving the solver support for the equation library, fixing various bugs found during development of that equation library, and optimizing the garbage collector.

Features

• ui: The keyboard layout is now configured by a a config/[keymap].48k file that describes which commands are assigned to which key by default. A new setup entry, Load keymap, lets you change the keyboard layout.

• ui: Add four predefined keyboard layouts:

  • db48x.48k is a key layout that is more logical and effective for DB48x See thread
  • legacy.48k is the layout used for earlier releases, which swaps the exp and log10 keys relative to the DM42 in 42style.48k.
  • 42style.48k keeps key layout as close as possible to the DM42
  • true42.48k is identical to 42style.48k, but the simulator shows an image of the DM42 keyboard.

• Add various commands such as Edit to directly perform editing operations in a programmatic way.

• units: Implement non-proportional unit conversions, notably temperature conversions like °F to °C. The underlying engine allows arbitrary conversions, including non-linear ones, which would be useful for example for the Dalton temperature scale. However, that capability is not presently used.

• units: Convert temperatures to K in multiplication and division. For example, when computing ⒸR*T, we need the temperature T to be in K even if given in Celsius or Farenheit initially.

• solver: Report underlying evaluation error. For example, if the expression being evaluated reports Inconsistent units, this is what the solver will return instead of No solution?.

• ui: Add configurable interval for busy cursor drawing, BusyIndicatorRefresh. The default is now 50ms, which refreshes the busy cursor more frequently than before, and may be detrimental to battery life and performance. You can restore the previous behaviour by setting a higher value, e.g. 1000ms.

• performance: Automatic cleanup of temporaries to minimize the number of garbage collection occurences. When a complex operation such as exp is performed, there are a number of intermediate results that require storage, and were previously only cleaned up by the garbage collector. They are now automatically cleaned up before the function returns. The same optimization applies to intermediate graphics while rendering equations, notably on the stack. This delivers significant performance improvements for long-running operations: the "floating-point sum test is now about 20% faster on SwissMicros calculators.

• commands: Add GCStats command to show garbage collector statistics.

• Allow CustomMenu to contain the name of a menu, or a program that builds the menu dynamically. An example is shown in the RPL directory of the Demo file.

• Allow CustomMenu to define "vertical" menus, i.e. menus where the items are stacked on top of one another.

Bug fixes

• Fix functions taking real-like unit input. For example, atan(1_cm/1_m) now computes correctly.

• solver: Do not solve system of equations using existing values. The multiple equation solver would incorrectly consider existing values in variables to check if an equation could be used for solving. The heuristic now picks up the equation that requires the smallest number of unknown variables among the available equations.

• Parse x! as factorial of x and not as a x! symbol. The incorrect parsing was due to an ambiguity in the HP48 parser that was resolved in the HP50G. DB48X now behaves like the HP50G and does not allow ! to appear at the end of a name.

• Do not enter the debugger if DebugOnError is set while evaluating an iferr statement. The assumption is that if you try to catch an error, you do not intend to debug the code being tested for an error. If this is not the desired behaviour, then an explicit DebugOnError should be inserted in the body of iferr.

• Various unit-related fixes in the equation library.

• Ensure that we don't execute auto-completed catalog commands twice. The recent change that added the auto-completed command to the command-line history also caused the command to be executed on the command-line before being evaluated again from the key.

• Avoid a rare crash when an equation was too big to be rendered graphically and a garbage collection cycle occured between graphic rendering and text rendering.

• Do not emit error message from Vec→ for vectors containing units. The incorrect error was introduced by the logic detecting polar, cylindrical or spherical vectors.

• Fixed atan2 special cases to always generate the correct angle. Cases where atan2 would generate an exact result would usually result in the wrong angle unit scaling being applied.

• Fixed parsing of tan⁻¹ in expressions.

• units: Skip the =Cycle section for unit definitions. This was causing incorrect unit conversion errors for users who had added common units in the =Cycle section of their config/units.csv file.

• The user-defined units menu no longer list all the built-in units after the user-defined ones.

• Add a missing sqrt in the RelativisticKineticEnergy sample code, and do not compute the kinetic energies for negative values.

• Alias keys is for KeyMap, not Header. Fix typo in identifiers table.

• Avoid a crash in RandomMatrix when hardware floating-point is enabled, due to an incorrect conversion to integer. As a side effect, fixed a couple of minor issues in the conversion to integer values from decimal or binary floating-point values.

• Fix bogus Bad argument type message for V→ when the number of elements was not 2 or 3.

• Fix crash when dividing a matrix by a non-invertible matrix.

• Fix crash displaying non-normal hardware floating-point values.

• Fix crash in vector operations that cause errors, e.g. [1][0] /.

• Parse ubase algebraic expressions, e.g. ubase(1_km), as well as other function-like commands such as size.

• Accept numerical values in ubase and leave them as is.

• Adjust the "next step" computation in the solver to minimize the complexity of conversions and remove unit ambiguity for temperatures.

• Rewrite the Heat Transfer equations to clarify temperature unit used in the computation. Specifically, avoid having a ΔT in a multiplication, where the value would be incorrectly converted to K.

• Fix a problem when a garbage collection while parsing a fraction could cause a large fraction of the subsequent program to be skipped. This normally led to anomalous Inconsistent units messages when this caused a unit such as 254/10_mm for in to be incorrectly parsed as 254/10.

Enhancements

• Major update to the documentation of the equation library, contributed by Jean Wilson.
• equations: Replace °F with °C in equations
• tests: Add support for tests that are known to fail
• tests: Run equation tests with 11 DIG
• tests: Add ability to take screen snapshots on failure
• units: Put temperatures before pressure in Fluids section
• help: Add image for B Field From Finite Wire
• Makefile: When using make update, do not keep the temporary .png
• Indicate where to get tac in the build documentation
• Fix README link to browser version
• Disable DebugOnError by default, since it confused new users
• Enhance the test suite so that it looks up the keys to use. This makes the test suite more readable, e.g. we have ID_exp in the test instead of D (the D key being where exp was on the original layout), and it makes the test suite layout-independent, paving the way for reuse on other hardware (e.g. HP50G).

Release 0.8.3 "Blindness" - User mode and custom header

This release focuses on various user interface aspects.

Features

• User mode, key assignment, ASN, STOKEYS, RCLKEYS, DELKEYS. Unlike HP calculators, key assignments are per directory, with inner directories inheriting the key assignments from the enclosing directories.
• Add Header command to customize the header. For example, you can now show the path in the header, or any relevant information. This customization can be done per-directory.
• Implement Menu, TMenu and RclMenu commands
• help: Automatically create links for references to RPL words. When we have sin in the Markdown file, the calculator will automatically insert a hyperlink to the corresponding entry. Note that this only applies to the calculator, not to the GitHub rendering of the Markdown files.
• Display object type in the Info box of the interactive stack.
• Fallback graphic rendering of objects to text when the usual heuristics did not allow the graphics to fit in the alloted pixel space. For example, a fraction that does not fit will now display using the textual form if that particular form can fit in the given box.

Bug fixes

• Fix a bug that could cause the text editor cursor to move past the end of the editor when inserting text, possibly causing memory corruption.
• The Show command will now show all digits, and render fractions using multiple lines for the numerator and denominator so as to be able to show more digits in a readable way.
• When terminating a command using auto-completion in the Catalog feature, the command that was entered is now present in the command-line history.
• Arithmetic operations that combine text or lists and unit objects now behave correctly. For example, adding a unit to a list appends like any other object.
• directories: Move updir if evaluating an updir directory, instead of corrupting the directory stack.
• Clear transient object if entering the interactive stack, e.g. when exploring the interactive stack while in the SolvingMenu and solving an equation, and correctly update the transient object when switching menus.
• Render vectors as RPL code in the equation examples.
• Correctly redraw the text editor when using the interactive stack Echo feature with stack items spanning multiple lines
• Fix minor typos in the equations documentation.

Improvements

• tests: Only evaluate after parsing RPL examples in the documentation when the stack is not empty
• The Wait command now returns a key code in the same style as HP calculators, i.e. with row, column and plane. Also, like HP calculators, it processes shift keys and returns a plane, instead of returning the keycode of the shift key.
• Capitalize Path, CrDir, Home, UpDir so that their rendering in compatibility mode with the Cmd setting looks better.
• Add DB48X_SPEEDUP environment variable support in the simulator.
• documentation: Update Authors section

Release 0.8.2 "Honor Seats" - Equation Library Examples, Assignments

This release is focusing on the testing, validation and usability of the equation library contributed by Jean Wilson. To that effect, it introduces a new kind of objects, assignments, that only exist on the DB48x and have no direct equivalent on original HP calculators. It also completes the support for library equations in the Root command.

Here is an example that illustrates these capabilities, testing the Ohm’s Law & Power equation in the library:

V=240_V  I=32_A
@ Expecting [ R=7.5 Ω P=7 680 W ]
'ROOT(ⒺOhm’s Law & Power;[R;P];[1_Ω;1_W])'

If you are reading this release note directly on the calculator, you can simply click ENTER while the text above shows up, and it will be copied in your editor. You can change the values of the input variables to explore various possibilities.

In this example, V=24_V is an assignment object that assigns the value 24_V to the global variable named V. It is almost equivalent to 24_V 'V' STO V, except that the value placed on the stack is the assignment object itself. In other words, evaluating V=24_V places V=24_V on the stack. This makes it easy to edit or evaluate assignments on the stack using the interactive stack. In particular, you can select an assignment on the stack wiht the interactive stack and use the Eval (F3) function to restore the variable to the value in the assignment.

The ROOT command in the example illustrates how you can directly use equations in the equation library as argument to Root, and use the multiple-equation solver to solve for more than one variable at a time.

All the examples in the on-line help are now also tested automatically, in order to ensure that all the given examples give the expected results.

Features

• Implement CustomMenu, whicih is toggled by successive presses on the VAR key. An example is shown in the Demo.48s file. The content of the CST or CustomMenu variable is used to define this menu.
• The documentation now contains numerous executable examples. These examples are identified by a Markdown code block with the rpl syntax colorization indicator. They can be executed directly from the on-line help on the calculator by hitting ENTER while the code block is shown on the screen.
• The test suite automatically tests all the documentation examples.
• Two new equation sets, Light Propagation and Ultrarelativistic Cases
• Four new equations in Energy & Momentum equation set
• Assignment objects in the form Name=Value, e.g. A=3.
• The solver now emits assignment objects for the solution
• ▶ command to store while keeping value on stack. As an extension relative to the HP50G, this command also works inside RPL algebraic expressions. For example 3▶A stores 3 in A and returns the value in A. The command is called Copy (the HP50G ARM calls it ▶ (Store))
• The Root command now accepts library equations as input.
• Arrays and lists are now accepted in algebraic expressions, using ; as a separator between values. For example, '[1;2;3]+[4;5;6]' adds two vectors using an algebraic notation. Vectors can contain algebraic expressions. For example '[x+1;y+2;z=3]' is a valid vector expression.
• The solver now accepts algebraic input, including for the multiple equation solver using vectors as input.
• Ad RombergPlot example to Library and Demo file. This example shows how the Integrate command evaluates the underlying function.
• menus: Add XRng and YRng to the PlotMenu

Bug fixes:

• Fix a sign bug in the Simple Slope equation
• Fix "Too many open files" error while saving constants, xlibs or equations
• Avoid infinite loop for unterminated case statement
• What follows a unit in an algebraic expression is no longer ignored. '330_m-20_m' was incorrectly interpreted as '330_m', now is '310_m'.
• Fix and document the Integrate imprecision and iteration settings.
• text: Respect display settings in →Str. For example, 3 FIX 0.1 →Str now returns "0.100" and not "0.1", like on HP calculators
• Repair parsing of HP-style complex numbers, e.g. (12;3)
• Refactoring of object insertion in text editor to fix various bugs, including the Echo command in the interactive stack inserting the object at the end of the text editor instead of at the cursor position.
• Do not issue Invalid digit for base on the console parsing 1E-10
• Fix null-dereference issue in to_decimal_if_big, which could be triggered if interrupting an Integrate command using the EXIT key.
• Avoid occasional garbage at right of menu area
• simulator: Ensure Copy correctly quotes equations
• Move image for E Field Finite Line to right section

Improvements

• Add references to keyboard overlays in the documentation
• Add documentation for the Root command
• Improve the way we generate the image files in the Makefile
• Improve solver behaviour when a solution is not found. Notably, the solver is more likely to converge towards an extremum.

Release 0.8.1 "Sale" - Multi-equation solver

Features

• Multiple-equation solver (HP's MES), solves for variables one at a time
• The | operator (aka where) applies to library equations
• The | operator respects variables with units in expressions
• simulator: Add support for copy and paste (to/from simulator)
• Add support for cylindrical and spherical 2D and 3D vectors
• Positional graphic combination operations (e.g. GraphicRatio)
• Switch to Greek or Cyrillic keyboard maps based on character menu
• Add EDIT menu commands to transient alpha (e.g. ▶F3 is Word→)
• Index the help file for performance (about 5x faster on DM42)
• Accept verbatim code and RPL code snippets in the help file
• Parse and show help topics taking all aliases into account
• Convert lists and equations to RPL programs with →Program

Bug fixes

• Show tagged values for vectors and matrices
• Update the target global variable after running root
• Show all variables in the SolvingMenu (with a settings to control it)
• Unit-related commands accept tagged objects and expression-enclosed units
• Add angular units (e.g. radians) in angular equations
• Correct unit for V in Cantilever Shear (was n instead of N)
• Purge now correctly restores UI patterns settings
• Add missing font parameter to →Grob (HP calculator compatibility)
• Include equations and xlibs to list of symbolic objects
• Fix precision loss for atan, acos and asin for some values
• Add angles for atan2 when using hardware-accelerated floating-point
• Remove spaces and separators in the names of library equations
• keyboard: Replace ASN with ->NUM
• Preserve trailing decimal separator in FIX mode with NoTrailingDecimal
• Fix backspace and delete operation around number separators
• Fix the definition of cosh for complex values (was computing sinh)
• Accept uppercase and lowercase .48s when saving/restoring state
• Accept both Ω or Ω as spellings for Ohm (different Unicode)
• Only update the state file when disk operations are successful

Improvements

• Add arcsin, arccos and arctan spellings
• solver: Reorganize solver code
• documentation: Udpate equation documentation with examples
• Save UI patterns as hexadecimal numbers (also in Modes command)
• Use only tabs in library.csv
• Keep cursor at end of buffer when moving through history with word right
• Clear selection when BSP is used with a non-empty selection
• Ensure debug_printf always refreshes the screen
• Switch to binary search for command parsing (~100x faster)
• Rename some statistical functions for consistency
• Fix the list of authors in the online help
• doc: Update performance data

Release 0.8.0 "Gabriel" - Symbolic operations, equations and library

This release adds symbolic integration, differentiation and equation solving, delivers an extensive equation library, and improves the library feature to enable large library objects to be defined in separate files and optimize execution speed for library items. It also improves the rendering of complex equations and fixes a number of crashes or user-interface problems.

Features

• Symbolic integration, Primitive command, '∫X(sin(X))' syntax '∫X(sin(2*X+3)-X)' evaluates as '-cos(2*X+3)/2-x²/2'
• Symbolic differentiation, Derivative command, ∂X(sin(X)) syntax '∂X(sin(2*X+3)-X)' evaluates as '2·cos(2*X+3)-1'
• Symbolic equation resolution, ISOL (Isolate) command 'sin(2*X+3)=A' 'X' ISOL gives 'X=(sin⁻¹ A+2*i1*π-3)/2'
• Apply arithmetic and functions on both sides of equations like A=B 'A=B' sin 1 + results in 'sin A+1=sin B+1'
• Add possibility to define library objects in separate files The various demos from previous releases are now also in the library
• commands: Add →Prog command to convert expressions to RPL programs 'sin(2*X-Y)' →Prog gives « 2 X × Y - sin »
• Accelerate evaluation of library entries Invoking a library object is as fast as if it was on the stack. Notice that this is faster than global objects that require lookup.
• Add ``Obj→support for user-defined function calls'F(A;B;C)' Obj→ DROP Obj→ ` gives `[F A B C]`. The first call to `Obj→` expands the expression, leaving an isolated function call on the stack, which the second `Obj→` expands.
• Automatically convert polynomial objects to expressions when needed
• Many improvements to the equation library contributed by Jean Wilson
• Document the equation library variables in the help file
• Add classical/relativistic Kinetic Energy comparison demo This was suggested by Jean Wilson as an illustration
• parser: Parse and convert HP syntax for | Typing 'A(X;Y)|(X=1;Y=2)' converts to 'A(X;Y)|X=1|Y=2'

Bug fixes

• Improve graphical rendering of some complex expressions
• Render sqrt as √ and not squareroot in HP compatibility mode
• Do not draw parentheses around |x| when rendering abs
• Redefine rpm as turn/min (unit consistency of rotational speed)
• Avoid crash in for loop if termination condition fails to evaluate
• Fix rendering and saving of directories
• Do not leave incorrect stack content when running Obj→ on text
• Make size consistent in vectors containing tagged objects
• Accept tagged objects as input in algebraic functions
• Avoid parsing error for 1,234 when . is the decimal separator
• Debug output related to expressions is no longer labelled "equations"
• Fix unit error in Drift Speed & Current Density
• Cut the size of the build version ID to avoid DMCP buffer overflows
• Avoid possible corruption when an error occurs in a program
• Improve error messages for file errors, e.g. when loading a state
• Move cursor at correct position after numbers when entering units
• Reject multiple consecutive units, e.g. 1_m_s
• Fix issue where we insert = incorrectly on the command line
• Address simulator warning about potential buffer overflow

Improvements

• tests: Add tests for the newly added library entries
• primitive: Add test suite for symbolic integration
• tests: Add test suite for symbolic differentiation
• Factor out code to expand objects on the stack
• make install now Installs from distribution files
• demo: Reorganize demo files as directories
• tests: Add test for Obj→ on various object types
• tests: Factor out code checking state of the complete stack
• tests: Avoid emitting something that looks like compilation errors
• Update demo file
• Improve definition of atomic mass unit, add Da (Dalton) alias
• expressions: Optimize the way to split an equation
• tests: Adjust tests after changes in SymbolicMenu

Release 0.7.18 "Who" - Subst, Where, Apply

This release implements the Apply, Subst and | (Where) commands.

Features

• ui: Allow Shift-SPC to enter = in an expression
• Implement subst and where
• Implement the Apply command
• Implement the EQNLIB command
• Add CONSTANTS as a way to select mathematical constants menu
• Add CONLIB as an alias for ConstantsMenu.

Bug fixes

• solver: Adjust detection of "epsilon" for large values
• ttf2font: Flip x coordinates for dense fonts

Improvements

• doc: List commands that will never be implemented

Release 0.7.17 "Open" - DoSubs, DoList, entering units

This release adds DoSubs, DoList, NSub and EndSub commands, and fixes related issues that were found with the associated examples in teh HP50G Advanced Reference Manual.

Features

• lists: Implement DoList, DoSubs, NSub and EndSub
• units: Add usual "big" units to Computing units menu (e.g. KB, MB)
• graphics: Add Freeze command
• ui: Make it easier to enter units
• expressions: Accept algebraic forms for integrate and root
• expressions: Graphical rendering of integrals

Bug fixes

• case: Preserve the code for the default case (which was lost before)
• parser: Parse arg-less alegbraic commmands such as NSub
• equations: Fix syntax errors in built-in equations, e.g. missing parentheses
• equations: Replace variables that match DB48X command names, e.g. Re
• equations: Replace imperial units with SI units, e.g. in with cm
• units: Reject user-defined functions in unit expressions
• constants: Fix definition for the qε0 constant

Improvements

• Update help about equations with some additional material
• tests: Run through all the builtin equations
• ui: Do not insert an extra space before parentheses in equation
• simulator: Add macOS icons for DB48X and DB50X
• font: Record saved font with v update

Release 0.7.16 "Clean" - New commands

The focus of this release is on new commands, notably for matrix and vector operations. This release also ships with a DM48X-specific keymap, which fixes a problem with teh file selector on the DM32. The equation library has been extended with numerous equations, but they are not fully validated yet.

Features

• con, idn and ranm matrix generation commands
• Array→ and →Array commands to convert array to/from stack
• dot product and cross product commands for vectors
• DispXY styled text rendering command
• DupDup command duplicating top item twice
• Add a large number of equations to equation library

Bug fixes

• Fix decimal::to_bignum for small magnitudes
• Return angle unit for atan2 and arg commands
• The for loop on lists no longer ends leaving the debugger active
• Interactive stack DropN command returns to level 1
• Fix file selector's "New file" on DM32 so that ENTER terminates it
• A few fixes in equations in the equation library

Improvements

• Improve graphical rendering of expressions such as multiplication operators
• doc: Update status
• font: Fix v glyph vertical placement, add dot and cross glyphs
• ttf2font: Add additional verbose info about source data
• Add CONSTANTS as an alias for ConstantsMenu
• Replace documentation references to EEX with ×10ⁿ
• Optimize parsing of real numbers in parentheses

Release 0.7.15 "Teaching" - Bug fixes notably on iOS

This release mostly focuses on issues exposed by the iOS releases. It's a bug-fixes only release.

Bug fixes

• ios: Fix a screen refresh bug delaying the display of computation results
• ios: Increase user-accesssible memory for DB50X to match the DM32
• files: Avoid opening two files when a loaded file contains units/constants
• units: Restrict unit expressions further, e.g. forbid 1_km^s
• build: Do not add unwanted macOS-specific files in release tar files
• build: Remove irrelevant help file from releae tar file
• constants: Fix numerical value for G constant
• tests: Rename M demo helper to D, since we use M in symbolic tests
• makefile: Add mv echo to targets doing image comparison
• units: Use pi constant in definition of radians unit
• parser: Detect syntax error on (inv(x)) in non-expression mode
• units: Avoid infinite loop for bad unit exponents
• files: Avoid crash in file_closer if file does not exist
• tests: Add DMS/HMS operations to math demo
• tests: Add keyboard shortcuts to launch the demos

Release 0.7.14 "Kids" - Equation-related bug fixes

This release fixes a number of issues that were discovered primarily through the Columns and Beams equations.

Features

• trigonometrics: Add conversion from non-standard angles, so that cos(1_turn) gives the correct result.
• debug: Debug on error with DebugOnError and KillOnError settings. This makes it easier to debug an RPL program, by making it possible to single-step around the instruction that generated the error.
• tests: Add three 30 second demo of DB48X features. These are to generate marketing videos for the iPhone version on the Apple store (to be done).

Bug fixes:

• ui: Keep a GC pointer in draw_object to avoid a memory crash
• equations: Add missing units in some equations, e.g. I and A in second equation of Coilumns and Beams
• equations: Add explicit radian unit in Eccentric Columns cos, which ensures we get the correct result from the HP50G manual even when in Degrees mode.
• units: Correctly factor out non-integral powers, so that we can compute 1/sqrt(epsilon_0*mu_0) and get the correct result.
• catalog: Display commands that begin with selection first, so that FORE shows Foreground before AlphaForeground.
• stats: When computing a sum, evaluate the expression on all terms. The result for Variance with single variables was wrong because the first term was computed incorrectly due to a misguided optimization.
• graphics: Error out in RGBPattern for negative input. The negative values were generating an error, but it was not reported, so the next command was likely to report it.
• help: Render shift keys correctly in the color version. The bitmap was interpreted as containing color data. Colorize it instead.

Improvement

• ui: Select orange as background color during search. The previous setting of showing seardch using white foreground on a white background was probably pushing the notion of "blind search" a bit too far.

Release 0.7.13 "Murderers" - Solver improvements

This releases focuses on improvements to the solver, with the completion of the Columns and Beams section from the HP50G equation library.

Features

• equations: Add remaining equations from "Columns and Beams"
• loops: For loops on lists and arrays
• menus: Add R→D, D→R, →Polar and →Rectangular
• menus: Automatically select tools menu for library equations
• units: Allow ubase to work on expressions
• units: Graphic rendering of units

Bug fixes

• 48calc.org: Fix mouse click position
• #ABC #DEF - now correctly produces a based number with >64-bit wordsize
• conditionals: Parse and evaluate IFTE correctly
• equations: Fix Elastic Buckling
• files: Avoid crash in file_closer if file was not open
• istack: Enable Swap feature on top two levels
• menu: Update SolvingMenu when updating VariablesMenu
• parser: Deal with negation more "normally", parse -a² correctly
• solver: Compute units correctly for inputs
• solver: Do not change unit when storing in a solver variable
• solver: Emit correct error message in EvalEq if missing variables
• solver: Preserve errors reported by underlying function
• units: Do not evaluate/render units with names
• units: No longer read variables m and s while processing 1_m/s
• units: Simplify units that convert to real numbers

Improvements

• Update .gitignore
• build: Add BMP files to the distribution
• complex: Optimize exit conditions for parentheses
• solver: Add test for equation library
• solver: Add tests for solving with units
• solver: Improve behaviour of EvalEq
• solver: Keep units and constants as-is in equation
• solver: Make precision relative to equation sides magnitude
• stack: Show vectors vertically by default
• ui: Do not persistently hide stack with current equation
• units: Keep power integral, i.e. avoid getting 1_m^2.0/s
• units: Strip tags from unit conversion functions
• units: The EvalEq command should not evaluate dates
• wasm: Add logos to the repository

Release 0.7.12 "Multiply" - Multiple equations

This release focuses on the equation solver, notably in interaction with the equation library. The goal is to get one step closer to the equation library in the HP50G, including the ability to have graphical illustration and multiple equations.

Features

• doc: Add documentation for the equation library
• doc: Add images from HP50G equation library (to be used later)
• doc: Some help for the elastic buckling equations.
• equations: Accept lists of equations in library
• help: Add documentation for the various constants
• help: Do not exit help when opening URLs or missing topics
• lists: Add a setting to evaluate list as programs
• menu: Add menu entries for solver imprecision and iterations
• solver: Add support for multiple equation solving
• ui: Add settings to hide/show empty menus and clear menu on EXIT
• units: Add flow units (per user request) in Fluid section of units

Bug fixes

• blitter: Adjust the right margin
• blitter: Base horizontal adjust on scanline, not width
• characters: Display correct content for built-in menus
• constants: Close current file while parsing values
• constants: Update some outdated values
• doc: Show help for equations and constants
• help: Do not try to load PNG images
• rewrites: Avoid contradictory rules when reordering constants
• solver: Work correctly with units (when in variables but not equation)

Improvements

• build: Shorten the size of the version abbrev
• config: Use config files only for user configuration
• doc: Record performance data about unit conversion
• help: Avoid slowing down when scrolling through pages of help
• help: Record position for history even without a \n
• simulator: Add tweak to show RPL object details
• tests: Increase wait time for tests with blinking cursor
• units: Do not simplify while in unit mode

Release 0.7.11 "Rest" - Refine interactive stack, graphics in help

This release is a refinement minor release. The primary focus is the interactive stack, which now lets you edit items, sort either according to memory representation or by value, display information about objects, and jump directly to a given stack level using digits.

The simple random number generator implemented in 0.7.10 was replaced with an additive congruential random number generator (ACORN), which can be configured in number of bits and number of iterations. A side effect is that there is now regression testing for single-variable statistics.

The history feature was also improved by automatically enabling the EditMenu when selecting history, and then having the (unshifted) word left and word right commands automatically cycle through history if used at beginning or end of the editing buffer.

Features

• help: Add ability to display BMP images in help files
• images: Convert help images to BMP
• ui: Add Edit feature to interactive stack
• ui: Add history menu entries to EditMenu
• ui: Accept UNDO while in interactive stack mode
• ui: Have word previous/next cycle through history
• ui: Accept digits to select stack level in interactive stack
• random: ACORN random number generator

Bug fixes

• editor: Fix spacing after number followed by - sign
• ui: Do not set the editing field from interactive stack
• ui: Replace interactive stack "Edit" with "Echo"
• ui: Block user input while using interactive stack
• ui: Do not draw menu markers when displaying interactive stack
• runtime: Avoid crash running above allocated memory in move_globals

Improvements

• ui: Reorganize code handling interactive stack keys
• help: Adjust help area to new height for menus

Release 0.7.10 "Hospitality" - Interactive stack

This release primarily adds the "interactive stack" feature of HP calculators.

Features

• stack: Interactive stack and associated menu
• functions: Very basic random number generator
• demo: Add CountPrimes and RandomPlot examples

Bug fixes

• menus: Do not execute if-then-else and similar
• expressions: Avoid error testing for zero/one in power operator
• condidionals: Avoid infinite loop evaluating condition
• menu: Insert iferr-then-else correctly from menu
• constants: Skip menu entries

Improvements

• menus: Reorganize stack menu to put Dup and Drop on first page
• menu: Add error functions to Debug menu

Release 0.7.9 "Just Asleep" - Online WASM simulator

This release includes a number of bug fixes, facilitates build from scratch by third-parties, and delivers a WASM-based simulator that runs on the https://48calc.org web site.

Features

• menu: Add Purge to the ClearThingsMenu
• purge: Add support for lists
• units: Accept units for sqrt, cbrt and xroot
• wasm: Add variant for 48calc.org
• wasm: Implement WASM support

Bug fixes

• complex: Give Syntax error for phasor without an angle
• dms/hms: Parse empty numbers in DMS entry
• dms/hms: Protect display against bad input
• editor: Make sure we reposition after shift-up and shift-down
• parser: Parse degrees as an angle unit in phasors
• simulator: Avoid high CPU usage when a timer is active
• simulator: Use the correct color for firmware text
• ui: Compute the correct refresh rate even when nothing is displayed
• ui: Create a non-empty dirty rectangle when clearing annunciators
• ui: Do not refresh beyond LCD size
• ui: Ensure we redraw the shift region to clear busy
• units: Disable simplification during unit definition evaluation

Improvements

• build: Fix the clean build
• object: Remove defaults for as_uint32 and similar
• parser: Cache parser::length when possible
• parser: Merge the parser::end and parser::length fields
• parser: Optimize integer parsing early exit
• simulator: Avoid Cancel in file save dialog
• simulator: Use https as a protocol for git submodules
• tests: Add support for degrees sign
• tests: Add test for polar angle conversion.
• units: Add factoring variable to limit simplifications
• wasm: Add link to deployed WASM simulator in the README
• wasm: Add script to add COOP / COEP headers
• wasm: Run the RPL thread in a separate thread

Release 0.7.8 "Mustard" - Constants in equations

This release keeps marching towards full support for an equation library. The primary focus was support for constants in equations, including constants with units like the speed of light, as well as fixing various user-reported issues.

Features

• cycle: Apply to value of tagged object
• equations: Add units to built-in equations
• equations: Adjust menu label to remove units
• equations: Strip units but not constants when rendering
• expressions: Treat 2X as an implicit product
• solver: Strip units from constants
• units: Unit prefix should preserve the tag

Bug fixes

• clearlcd: Fix erasure of screen when not in graphics mode
• constants: Count number of menu entries correctly for builtin menus
• decimal: Accept leading . or , for decimal values
• expressions: Parse negation after parentheses
• sum: Do not accept a non-name in a sum or product
• type: Return a type value for decimals
• ui: Fix insertion/editing of infix with alphabetic names
• units: Do not read units from variable if they exist
• xroot: Reverse xroot arguments in algebraic parsing

Improvements

• editor: Shuft-up returns to beginning of line if on first row
• errors: Add error_save class, use it in constant::value
• expressions: Use the SaveAutoSimplify class in simplify_products
• units: Split Eng to Elec and Visc

Release 0.7.7 "Forgiving" - Units in equations

This release keeps marching towards full support for an equation library. The primary focus was support for units in equations.

New features

• solver: Accept equations in solver menu
• solver: Add shortcut to solve an equation from the library
• solver: Display the current equation above the stack
• solver: Solve expressions containing units
• solver: Add units for solver variables when entering them
• equations: Add option to list variables with units
• programs: Enforce numerical values for solver / plotter
• constants: Implement programmatic lookup
• fonts: Add support for fixed-width digits
• keyboard: Interpret ASN as AsNumber (convert to decimal)
• complex: Allow insertion of angle while entering phasors
• complex: Implement auto-complex promotion
• graph: Render abs(X) with bars (e.g. |X|)
• functions: Automatic simplification of expressions

Bug fixes

• arithmetic: Avoid null-dereference in complex operations
• help: Close help file if topic not found
• solver: Do not store tag for tagged values
• graph: Gracefully fallback if fraction integral part does not render
• units: Avoid null-dereference if unit simplification fails
• units: Count parentheses while parsing units
• put: Fix null-dereference checking the index
• fractions: Do not render two negative signs in graphical mode

Improvements

• cycle: Update behaviour for several data types
• menu: Replace abs with |z| in complex menu
• ui: Micro-optimization to avoid reading object type twice
• parser: Accelerate and improve object parsing
• recorder: Add recorder entries for evaluation
• build: Remove any leftover references to Intel decimal library
• tests: Add ▶ entry in tests
• tests: Increase default wait time to 1000ms
• tests: do not error out if teval takes less than 100ms
• equations: Rename PerfectGas equation to IdealGas
• menus: Adjust size of menus to make descenders visible
• solver: Replace SolverPrecision with SolverImprecision

Release 0.7.6 "United" - Equation Solving Menu

This release is primarily about implementing a dynamic solving menu that makes it easier to solve equations with multiple variables. This is roughly equivalent to the "Solve Equation" application in the HP50G.

New features

• solver: Implement solving menu
• tag: Graphic rendering for tagged objects
• lists: Implement lname and xvars commands
• arithmetic: Implement div2 command
• variables: Implement vars and tvars commands

Bug fixes

• render: Avoid errors while rendering / graphing
• expressions: Avoid consuming stack levels for invalid expressions
• symbols: Avoid ignoring the list of bad characters in symbols
• command: Fix for x! parsing
• stack: Correctly set clipping for stack index
• doc: Fix typo in release note

Improvements

• menus: Add PixOn, PixOff, Pix? and PixC? to GraphicsMenu

Release 0.7.5 "Perfect Joy" - Polynomials and symbolic rewrites

This release contains a lot of groundwork in preparation for future work on symbolic expressions, symbolic solving and symbolic integration, as well as to improve compatibility with HP calculators. In particular, rewrite has been replaced with the HP equivalents, ↑Match and ↓Match, allowing top-down and bottom-up replacement, as well as support for conditions. Also, these commands return the number of replacements performed instead of just 0 or 1.

THe other major user-visible new feature is the addition of a polynomials data type, which does not exist on HP calculators, exposing polynomial features in a way that is more consistent with the spirit of RPL. For example, Euclidean division of polynomials can be achieved using the regular / operation on polynomials instead of requiring a dedicated DIV2 command.

New features

• Support for polynomials as a data type, including Euclidean division
• Arithmetic operations on polynomials, including sq and cubed
• Conversion functions →Poly and Poly→ to convert to and from polynomials
• Optional case-sensitive symbol matching
• Algebra configuration directory (like CASDIR on HP calculators)
• rewrites: Replace rewrite command with HP-compatible ↑Match and ↓Match
• rewrites: Add ExplicitWildcards option to match HP syntax (&A)
• rewrites: Add rules to expand powers
• rewrites: Add support for conditions when matching patterns
• rewrites: Add support for step-by-step rewrites
• rewrites: Add support for bottom-up rewrites
• flags: Purge now resets system flags to default value

Bug fixes

• editor: Fix unresponsive keys after using EXIT key while searching
• complex: Avoid emitting syntax errors while parsing
• rewrites: Avoid potential garbage collection corruption problem
• rewrites: Disable auto-simplification during rewrites
• rewrites: Factor out rewrite loop
• expressions: Encode expressions with type ID >= 128 correctly
• arithmetic: Add space around mod and rem in rendering
• graph: Do not add parentheses for X*(Y/Z)
• functions: Make percentage operations binary functions
• functions: Turn min and max into algebraic functions
• cycle: For expressions, cycle graphic/text rendering correctly
• menus: Replace EquationsMenu with ExpressionMenu in other menus
• ui: Insert space when inserting array inside function

Improvements

• menus: Updates to PolynomialMenu to enter polynomials and for conversions
• menus: Add product and sum to symbolic and algebra menus
• menus: Make ToolsMenu select SymbolicMenu for symbols
• expressions: Reorganize the code for rewrites
• rewrites: Add recorders for rewrites that are actually done
• tests: Some adjustments on color images
• rewrites: Convert algebraics into expression as needed
• complex: Parse 3i and i3 in addition to i
• tests: Add support for more characters
• simulator: Separator color and dm32 support
• graph: Add space when rendering simple function
• keyboard: Updated SVG files with latest menu labeling changes

Release 0.7.4 "Flesh" - Polishing and refinements

This release is mostly about polishing various aspects of the implementation to make it more convenient and more efficient. It also adds user-defined functions parsing and evaluation, pixel-manipulation commands, bit operations on binary numbers, memory operations like sto+ or incr, loading and saving BMP files, color support in the simulator, and more.

New features

• editor: Implement configurable word wrapping
• expressions: Add code for n-ary functions like sum
• expressions: Parse user-function calls like F(1;2;3;4)
• expressions: Ensure funcall objects are evaluated immediately
• functions: Add sum and product functions
• functions: Add combinations and permutations
• functions: Implement number rounding operations (rnd and trnc)
• graph: Add graphical rendering for cbrt (cube root) and xroot
• graph: Graphical rendering of combinations, permutations
• graph: Graphical rendering of sum and product
• graphics: Add pixon, pixoff and pix? commands
• graphics: Store and recall BMP files with sto and rcl
• graphics: ToGrob command converting object to graphic
• logical: Add SetBit, ClearBit and FlipBit commands
• memory: Implement the Clone (NewOb) function
• menus: Add log2 and exp2 to ExpLogMenu
• menus: Place ListMenu as a keyboard-accessible menu
• parsing: Parse n-ary functions
• program: Add vertical program rendering mode
• stack: Display error message emitted during stack rendering
• ui: Add colorization parameters for the user interface
• ui: Add some colorization
• variables: Add Sto+, Rcl+ and other variable arithmetic
• variables: Implement Increment and Decrement

Bug fixes

• decimal: Fix precision when computing gamma/lgamma
• decimal: Fix rounding bug when rounding increases exponent
• doc: Add missing dependencies on Fedora (submitted by @vkadlcik)
• files: Do not error when opening constants/equation/library files
• files: Open only one configuration file at a time
• graphics: Fix bug drawing a line of width 0
• graphics: Use foreground color for parenthese and ratio
• lists: Separate list sum/product from regular sum/product
• renderer: Make sure printf respects target buffer size
• simulator: process double-clicks correctly (submitted by @kjellc)
• tests: Change the height of ignored header

Improvements

• command: Factor out arity for all commands
• constants: Report parse error location for invalid constants
• demo: Add HP-48 style slow walk to Walk demo
• demo: Modernize the code a little
• demo: Modify performance benchmarks to use TEval
• demo: Replace imaginary unit constant
• doc: Remove reference to Intel Decimal Library
• files: Convert all file names to lowercase (Linux support)
• functions: Make it possible to interrupt a running sum/product
• graph: Improve rendering of exp, exp2, exp10
• graphics: Separate color conversion step
• help: Do not display command name while editing
• ids: Make room for a few additional 1-byte commands
• locals: Document the absence of compiled local variables
• makefile: Add configuration files to the release .tgz file
• parsing: Make the error message for sub-expressions more local
• readme: Remove reference to DM42 from top-level readme
• simulator: Avoid crash rendering %t in recorder
• simulator: Convert simulator code to support color
• simulator: Replicate open files limitations
• simulator: Separate db50x and db48x builds
• tests: Add colorized images to testing
• tests: Avoid occasional errors on some long-running tests
• ui: Define cursor position in SelfInsert with \t
• ui: Ignore EXIT, BSP and ENTER keys when clearing error

Release 0.7.3 "Perfume" - Mostly bug fixes

This release is mostly about bug fixes, improving the build on simulator, and accelerating the test suite while keeping it stable.

New features

• simulator: Add F8 key to save state in the simulator
• errors: Add a beep when an error is shown
• linux: Add -s option for screen scaling (when Qt gets scaling wrong)
• equations: Get library equation value for plotter, solver and integrator
• characters: Add constant, equation and lib markers to RPL menu
• characters: Add music-related characters and character menu
• commands: Add missing stack commands (nip, pick3, ndupn, unrot, unpick)

Bug fixes

• variables: Clone purged objects on stack after Purge
• units: unit * symbolic is preserved as is (e.g. 'A'_m)
• compare: Enforce the NumericalResults flag for comparisons
• constants: Fix parsing of constants, equations and library items
• sto: Repair file exists error storing to a source file
• simulator: Do not try to create directory if it exists
• Report file errors, e.g. permissions or I/O errors
• equations: Mark c and R as constants in equations
• simulator: Double clicks are now considered as virtual keyboard touches
• ui: Emit only one beep, not two, for a syntax error on the command line
• ui: Avoid rare null-dereference crash when menu label is not set
• complex: Report a syntax error if the second half is empty
• utf8: Do not accept constant/equation/library codepoint in names
• units: Multiplying by 1_m is OK even with algebraic
• tests: Avoid case where CLEAR does not clear errors
• audio: Improve audio reliability on the simulator
• linux: Rewrite the audio-generation code to avoid crashes
• linux: Avoid infinite recursion in the tests
• linux: Fix warnings about unused variables
• linux: Avoid warnings about null pointer in strcmp
• linux: Avoid build error due to bad ularge overload in settings
• linux: Fix type issue for the Insert function (reported as a warning)
• linux: Remove warning about mixing enums and integers
• linux: Avoid error on printf format
• linux: Avoid warnings about type qualifiers
• linux: Remove warnings about incompatible function casts
• linux: Address warnings about missing initializers
• linux: Fix warning about prinf formats
• linux: Address warning about signed vs unsigned
• linux: Remove warning about fall-through switch statement
• linux: Remove warnings about unused arguments
• tests: Repair several tests that were unstable due to scrolling images
• tests: Increase memory size to avoid occasional out of memory failures
• object: Make as_uint32 and as_uint64 consistent for negative input

Improvements

• ui: Emulate HP48/HP50G behavior for errors (do not require key to continue)
• simulator: Add I/O wrapper around file state save/restore
• dmcp: Remove double return in the code
• simulator: Accept numeric keys in DMCP menus
• doc: Add Kjell Christenson to list of authors
• tests: Run command-line tests silently
• tests: Clear settings the fast way for quick tests
• dmcp: Do not treat the buzzer as a recorder error (avoid message noise)
• simulator: Ensure error messages show up in a recorder dump
• tests: Increase memory size to avoid failing tests
• tests: Increase delay waiting for function plots to appear
• tests: Refactor test suite interaction with RPL thread to accelerate it
• tests: Add a delay before launching the test thread to load initial state
• tests: Add missing reference picture for char-menu

Release 0.7.2 "Light" - Libraries, Characters menu

This release introduces four relatively significant features:

1. An Equation Library
2. A more general Library
3. Character menus
4. A character modification catalog

There are also a number of bug fixes and improvements.

Features

• The Equation Library is similar in principle to what is found in the HP50G. It is intended to store equations covering a variety of topics. The Equation Library is accessible using the EQS key (🟦 '()'). It is presently only very sparsely populated, but a future release should add the equations listed in Chapter 5 of the HP50G Advanced User's Reference Manual. Elements of the Equation Library appear as named Equation Objects. The Equation Library is configured by file config/equations.csv.

• The Library is similar to the Equation Library, but for all kinds of objects such as programs or code snippets. The Library is accessible using the LIB key (🟦 VAR). It can be used to customize your calculator, and is intended to play the roles of the CST variable (quick access to common features) and Library Objects / XLIB (external extensions to RPL). Elements of the Library appear as named Library Objects. The Library is configured by file config/library.csv.

• The Characters Menu lets you enter Unicode characters easily, by presenting various classes of characters, such as RPL, Greek or Punct. The Characters Menus is accessible using the CHAR key (🟦 2). It can be used to enter international characters (e.g. Greek or Cyrillic), as well as special characters such as arrows or blocks. The Characters Menu is configured by file config/characters.csv.

• The Characters Catalog appears when the Catalog is active and the cursor is inside some text object. It gives you access to characters that are visually close to the character on the left of the cursor. For example, after typing A, the presented choices include À, a or α. The Characters Catalog is configured by file config/characters.csv.

• compare: Add comparisons for true and false values

• Add TEVAL command (timed evaluation)

Bug fixes

• Do not add unnecessary parentheses in ratios, e.g. (A+B)/(X-Y)
• Make sure we can save back the configuration files correctly
• Improve access path checks to accept config:constants.csv.
• Avoid syntax error in 1/(1+x) due to 1/ being seen as a fraction
• unitfile: Remove slight risk of bad menu display after garbage collection
• date/time: Make sure we save the stack and last args for Date, Time, ...
• parser: Skip spacing when parsing numbers (to parse back →Text result)
• time: Fix rendering of DMS time in lists, matrices, vectors
• catalog: Fix a subtle bug on DM32 leading to a crash using the catalog

Improvements

• constants: Get values of special π and e by name
• constants: Add prefix in editor to identify constants, equations and xlib
• constants: Represent constants with an index for memory and performance
• constants: Parse units containing text
• constants: Allow RCL to recall a constant value
• units: Direct insertion of units after numbers
• menu: Update Roll and RollDown menu entries
• show: Show all decimals for decimal values
• help: Display the correct on-line help topic for constants
• catalog: Use less memory for the sorted IDs
• integrate: Use numerical computations for faster convergence
• locals: Improve error message for bad locals
• graph: Improve graphical rendering of constants (bold) and equations
• graph: Do not add unnecessary parentheses in ratios
• tests: Add tests for characters menu/catalog
• tests: Fix the . vs 0. test
• ui: Do not enter DMS inside text
• tests: Display disabled tests in gray
• catalog: Keep a single spelling, e.g. no add duplicates
• tests: Add extra delay in the wait for update
• makefile: Add dependency of 'all' to the decimal constants
• save: Improve rendering control when saving files
• stack: Do not save stack in plot, integration or solver
• debug: Disable debugging when launching a program from function key
• simulator: Avoid piling up QT draw requests
• doc: Update performance numbers for 1M loops
• simulator: Add sound support
• simulator: Lazy screen refresh
• dmcp: Add UI refresh callback
• simulator: Move QT-dependent code out of dmcp.cpp
• Add reduced font
• runtime: Various changes to isolate QT build from the rest

Release 0.7.1 "Whip" - Bug fixes

Inserting variables, constants or units in a program was broken. Also a few less critical fixes.

Bug fixes

• decimal: Apply MinimumSignificantDigits to Sig modes
• tests: Fix missing ] at end of vector
• ui: Insert commands for unit conversions, constants and variables
• tests: Adjust help screen snapshot for authors
• menus: Do not clip text for hierarchical menus
• constants: Do not use units that don't parse correctly
• dmcp: Day of week convention adjustment
• help: Fix YouTube video preview

Release 0.7.0 "Temple" - Graphics Equation Rendering

This release introduces a few major improvements, including graphical rendering of equations and matrices, the Show command to display large objects full-screen, customizable constants, and date-related operations.

New features

• Graphical rendering of equations, fractions, matrices, vectors and lists. In graphical rendering mode, variables are showin in italics.
• Constants in the ConstantsMenu, split into categories, and loading from an optional config/constants.csv file, in a way similar to what existed for units.
• Inverse trigonometric functions (asin, acos and atan) now produce unit objects with the current angle mode as a unit. This can be configured by the SetAngleUnits / NoAngleUnits flags.
• Cycle (×10ⁿ key) now cycles between angle units.
• R→D and D→R commands to convert between degree and radian in a purely numerical way (no unit). This is for compatibility with HP.
• Add →Deg, →Rad, →Grad, →πr commands, which convert a number to the target unit using current angle mode, and convert an angle to the target angle unit.
• Conversion from DMS to HMS and from HMS to DMS
• Rendering of dates: 19681205_date renders as Fri 5/Dec/1968, with a format configuration using the same flags as for the header. Note that the date format is YYYYMMDD, not the same as on HP calculators. This allows YYYYMMDD.hhmmss for dates with time.
• Date and Time command to return the current date and time. Additionally, DateTime returns both date and time, and ChronoTime returns the time with 1/100s precision.
• →Date and →Time commands to set the system date and time
• Date+, DDays and date arithmetic using + or -, using day units for the results. As an extension relative to HP calculators, these will accept fractional days, or other time units. For example, adding 1000000_s to 19681205_date generates a date with time result, Tue 16/Dec/1968, 13:46:40
• JulianDayNumber and DateFromJulianDayNumber commands to convert between dates and Julian day numbers. These commands also accept fractional input.
• Show command showing a full-screen graphical rendering of the result on the stack. The resut is size-adjusted. For example, you can display all digits in 200!. If the result does not fit on the screen, you can scroll using the ◀︎ and ▶︎, as well as 8, 6, 4 and 2. The maximum pixel size for Show is set by MaxW (default is the width of the LCD), the maximum height is set by MaxH (default is 2048 pixels).
• AutoScaleStack and NoAutoScaleStack settings to automatically adjust the font size for the stack elements.
• Support for system flags -20 to -26 (infinite results, overflow and underflow).

Bug fixes

• simulator: Adjust DMCP month off-by-one error
• Repair insertion of while loops and similar commands on the command line
• Use stack format when drawing an object with DrawText (DISP)
• Arithmetic on unit objects no longer auto-simplifies, e.g. 1_s 1_s - returns 0_s and not 0.
• Perform computations for →Q using integer values, which avoids an issue where increasing the number of iterations with an unachievable precision could prodduce 1/1 as the fractional result.
• Repair auto-simplification for i*i=-1
• Display a negative mixed fraction as -1 1/3 and not 1 -1/3.
• Do not insert () after a multiplication in algebraic mode
• Accept units and tagged objects in PolarToReal and RealToPolar
• Accept angle units as input for →DMS
• Off-by-one clipping error in header, erasing the shift annunciator
• Fix help for FC? (incorrectly stating that it tested for flat set)
• Lookup units and constants in a case sensitive way
• Fix labels for ExpFit and LinFit in RegressionMenu.

Improvements

• tests: Adjust tests to match bugs fixed in v0.6.5
• dms: Accept entering minutes without third dot, e.g. 1.2.3 ENTER
• menus: Split the Time, Date and Alarm menus
• Split rendered objects at space boundaries. This notably ensures that large numbers are split at digit grouping boundaries, and makes it possible to display larger programs on the stack. The rendering of programs and matrices/vectors/lists has also been fine-tuned.
• The "white circle" glyph has a thicker border, makes it more readable in menus.
• doc: Update the list of unimplemented features
• menus: Draw a white circle for disabled flags, and allow the menu function to toggle the flag. This made it possible to reduce the number of menu entries for flag-heavy menus.
• Mixed fractions are now the default, as opposed to improper fractions
• doc: Improve the quickstart guide
• doc: Improve the documentation for sin, cos and tan
• tests: Make it possible to interrupt a running test
• help: Skip HTML tags, e.g.
• simulator: Add screenshot capability, and reduce window height
• menus: ToolsMenu selects time, date or angle menu based on units

Release 0.6.5 "Testimony": Small bug fixes

This release does not contain much because FOSDEM took a lot of energy.

New features

• menu: Connect ceil and floor functions
• Add real to polar conversions
• units: Add dms unit to angles menu

Bug fixes

• decimal: Compute ln(0.002) correctly
• integer: Do not parse degree sign if in a complex
• units: Fix parsing of angle units
• font: Add radian glyph

Release 0.6.4 "Healing": Testing and fixes

This release focuses on heavy testing of the new variable-precision decimal stack. Adding tests also means finding bugs.

Another significant change is support for fixed-precision hardware-accelerated floating point, using 32-bit and 64-bit IEEE754 binary floating-point representation. Since this uses a binary format, some decimal values do not map to decimal correctly. For example, displaying 1.2 with a large number of decimals will show residue, because 1.2 does not have an exact (zero-terminated) representation in binary.

New features:

• plotting: Make refresh rate configurable
• menu: Add / key to FractionsMenu
• hwfp: Add support for hardware-accelerated floating-point
• menus: Add hardware floating-point flag to MathModesMenu
• ui: Allow multiple uses of . to insert DMS separators
• HMS: Editing of HMS values in HMS format

Bug fixes:

• stats: Fix crash on variance with single-column statistics
• algebraic: Clear error before evaluating the function
• functions: Correctly emit a type error for non-algebraics
• ui: Make sure we save stack if closing the editor
• logical: Fix mask for rotate left with 64-bit size
• logical: Make sure we save args for single-argument logicals
• flags: Update flags on FlipFlag, consume them from BinaryToFlags
• stack: Show multi-line objects correctly
• lists: Returns Bad argument value for index with bad arguments
• lists: Return an empty list for tail of empty list
• arithmetic: →Frac should not error on integers
• power: Do not shut down during WAIT if on USB power

Improvements:

• menu: Shorten the labels →QIter and →QPrec to avoid scrolling
• stack: Avoid running same code twice on simulator
• ids: Add aliases for hardware floating point
• functions: Optimize abs and neg
• ui: Replace calls to rt.insert with calls to insert
• menu: Reorganize fractions menu
• dms: Do the DMS conversion using fractions
• list: Adjust multi-line rendering
• copyright: Update copyright to 2024
• text: Return null text when indexing past end of text

Testing:

• tests: Increase the delay for help to draw
• tests: Add tests for hardware-accelerated floating-point
• tests: Add shifts and rotate tests
• tests: Check flag functions
• tests: Test DMS and HMS operations
• tests: Add test for integrate using decimal values
• tests: Test multi-line stack display
• tests: Add tests for GETI
• tests: Min and max commands
• tests: Repair last regression test
• tests: Check behaviour of 0^0
• tests: Avoid string overflow in case of very long message

Release 0.6.3 "Come and See": Repair test suite

The focus of this release was to reactivate the test suite and fix the problems that were found activating it.

New features:

• HMS and DMS operations
• unit: Rendering of dms and hms units
• Allow · as a multiplication sign in equations
• ui: Display 'E' cursor inside parentheses
• graphics: Accept based integers as position for DrawText
• complex: Add setting to switch between 2+3i and 2+i3.

Bug fixes:

• decimal: Fix precision loss for addition with carry
• Base: limit range of bases to 2-36
• files: Do not add a trailing zero when reading a text file
• decimal: Adjust MinimumSignificantDigits behaviour
• units: Do not auto-simplify 1.0 during conversion
• decimal: Normalize parsed numbers
• solver: Fix sign error in epsilon exponent for solve/integrate
• parser: Accept x! as input
• simulator: Avoid faulty break-through in switch statement
• complex: Make tag higher-priority than complex
• editor: Adjust cursor and select correctly during replace
• decimal: Fix display of 0.2 in NoTrailingDecimal mode
• complex: Save this in a GC pointer when it can move
• arithmetic: Do not fail because of surrounding error
• decimal: Clamp int32 conversions from decimal
• commands: Parse exp10 correctly in expressions
• decimal: Avoid infinite loop computing expm1
• ids: Do not allow parsing of structures
• dmcp: Make sure the tests don't block on wait_for_key
• decimal: Use correct angle unit for negative gamma values

Improvements:

• settings: Add classes that save/restore a given setting
• Add XSHIFT to shift to XSHIFT state directly
• Add NOSHIFT constant to simplify test writing
• ui: Add a variant of close_editor without trailing zero
• decimal: Cache gamma_ck values (accelerate gamma and lgamma)
• Replace magic constant -1 with EXIT_PGM
• doc: Record performance data for 1000 iterations of SumTest
• decimal: Add tracing for gamma / lgamma function

New tests:

• Add tests for arithmetic truncation on short bitsizes
• Add tests for on-line help
• Add test for plotting flags
• Add test for Unicode to text conversions
• Add test for rectangular complex display options
• Add tests for plot scaling functions
• Add tests for the sorting functions
• Add test for parsing text with quotes inside
• Add test for file-based STO and RCL
• Add test for 2^256 computation (buf #460)
• Fix indentation of [PASS] or [FAIL] for UTF8 characters
• Add tests for units and conversions
• Add a keyboard test checking the single-colon insert in text
• Add test for i*i=-1 auto-simplification
• Add basic test for numerical integration
• Add test for fraction formats
• Add solver test
• Add missing tests
• Add test for immediate STO (#390)
• Add tests for the Cycle command
• Add test for catalog feature
• Add test for "smart" keyboard shortcuts introduced in 0.4.6
• Add regression test for #371
• Add tests for editor operations
• Test stack operations
• Add test for GXor, GOr and GAnd
• Add test for ResetModes
• Add plotting test for every decimal function
• Add image checking for graphical tests
• Add tests for graphic and text drawing commands
• Make it possible to individually run tests.
• Add plotting tests
• Add test parsing the various spellings for commands

Release 0.6.2 "Kephas": Restoring the test suite

The focus of this release was to complete the transition to the variable-precision decimal code. The full regression test suite was restored, with only two tests still failing (complex asin and asinh). The two missing functions, Gamma and LogGamma, were implemented. This also exposed many bugs that were fixed.

New features:

• NumberedVariables setting to allow 0 STO to ease RPN transcoding (#690)
• ClearStack (CLEAR) command
• Variable-precision gamma and lgamma functions (#710)

Bug fixes:

• Do not leave bad expression on stack after error (#663)
• Reject unit conversion between undefined units (#664)
• Accept names of menus on the command line (#669)
• tests: CLEAR clears stack and errors (#672)
• The : characters now starts a tag on empty command line (#673)
• Do not evaluate tagged objects too early (#674)
• test: Entry and editing of equations (#677)
• test: type returns negative values in "detailed" mode (#678)
• Run loop end pointer not GC-adjusted for last allocated object (#679)
• Do not erase alpha indicator when clearing busy cursor (#680)
• Do not emit trailing space when rounding 1.999 to 2. (#687)
• Allow expression rewrites to deal with pow (#694)
• Reject « character in symbols and commands (#695)
• Rendering of spacing for decimal numbers (#699)
• Improve precision of atan function
• Rendering of + and - operators in compatibility modes (#700)
• Rounding of decimal numbers no longer generates bad characters (#702)
• No longer error out rendering symbolic complex (#703)
• Parse complex numbers correctly inside equations (#704)
• Ensure sqrt(-1) has a zero real part (#705)
• Do not drop last digit of decimal subtraction (#706)
• Evaluate expressions during expression pattern matching (#708)
• LastMenu executes immediately while editing (#711)
• Add back missing angle glyphs in font (#712)
• Return correct angle quadrant for atan2 (#715)
• Get no longer rejects arrays as index values (#718)
• Get returns correct error for bad argument types (#718)

Improvements:

• Update .gitignore entry
• Automated testing of setting flags (#657)
• Automated testing of non-flag settings (#670)
• Test fixed-base based numbers using HP-compatible lowercase notation (#675)
• Test fraction rendering using fancy digits (#676)
• Add test for "compatible" variant of type command (#678)
• test: Recover from error during data entry (#681)
• Increase default MaxNumberBits to 4096 (#686)
• tests: Add test for cube root of -8 (#685)
• tests: Data entry for Σ, ∏ and ∆ (#689)
• Restrict STO to names, natural numbers and specific IDs (#688)
• doc: Document flas file access for STO and RCL (#691)
• list: Optimize iterators to avoid copies (#692)
• tests: spacing-independent testing of structure rendering (#693)
• tests: adjust test suite for variable-precision decimals (#696)
• tests: Automatically exit if -T option is given (#697)
• tests: Check we don't accept . as meaning 0. for RPL compatibility
• Add modulus alias back for abs (#707)
• Improve convergence speed and accuracy for logarithms
• Add decimal::make to minimize risk of sign errors
• Display stack level at top of stack level, not bottom (#709)
• Improve complex sqrt accuracy on real axis (#714)
• tests: Test decimal functions at full 34 digits precision (#716)
• Complex sqrt and cbrt with full precision (#717)
• tests: Take into account additional expression simplifications

Release 0.6.1 "Happy New Year": Quick bug fixes

A few quick bug fixes that make DB48X a bit more usable.

New features

• Setting to display 2+i3 instead of 2+3i (#660)
• HMS and DMS operations (#654)
• Special 1_dms and 1_hms units rendering in DMS / HMS (#650)

Bug fixes

• Improve behavior of +/- key while editing (#658)
• Do not accept base 37 (#656)
• Insert for statement in program instead of executing it (#655)
• Hide trailing decimal separator for decimals with integer values (#653)
• Fix display of 19.8 with 0 FIX (#652)
• Implement true decimal to integer conversion (#648)

Improvements

• doc: Record performance data for 0.6.0
• doc: Udpate status file

Release 0.6.0 "Christmas": Introducing variable precision

This release was a bit longer in coming than earlier ones, because we are about to reach the limits of what can fit on a DM42. This release uses 711228 bytes out of the 716800 (99.2%).

Without the Intel Decimal Library code, we use only 282980 bytes. This means that the Intel Decimal Library code uses 60.2% of the total code space. Being able to move further requires a rather radical rethinking of the project, where we replace the Intel Decimal Library with size-optimized decimal code.

As a result, release 0.6.0 introduces a new table-free and variable-precision implementation of decimal computations. In this release, most operations are implemented, but some features are still missing (e.g. Gamma function). This release will be simultaneous with 0.5.2, which is functionally equivalent but still uses the Intel Decimal library. The new implementation is much more compact, allowing us to return to normal optimizations for the DM42 and regain some of the lost performance. On the other hand, having to switch to a table free implementation means that it's significantly slower than the Intel Decimal Library. The upside of course is that you can compute with decimal numbers that have up to 9999 digits, and a decimal exponent that can be up to 2^60 (1 152 921 504 606 846 976).

New features

Variable precision decimal floating point implementation for arithmetic, trigonometrics, logs, exponential and integer factorial. Other functions may still return "unimplemented error".

Bug fixes

None. If anything, this release introduces bugs in computations and performance regressions. However, it frees a lot of space for further DM42 development.

Improvements

The Precision setting now sets the number of digits with a granularity of one, between 3 and 9999. Ideal use of memory is with multiples of 12 digits, e.g. 12, 24 or 36 digits, where decimal packing does not cause lost bits.

Performance on the DM42 is somewhat improved, since it is now possible to return to a higher level of optimization.

Regressions

In addition to lower performance and unimplemented functions, this version no longer builds a compatible QSPI. This means that returning to the DM42 requires flashing both the QSPI and the PGM file.

Release 0.5.2 "Christmas Eve": Reaching hard limits on the DM42

This release was a bit longer in coming than earlier ones, because we are about to reach the limits of what can fit on a DM42. This release uses 711228 bytes out of the 716800 (99.2%).

Without the Intel Decimal Library code, we use only 282980 bytes. This means that the Intel Decimal Library code uses 60.2% of the total code space. Being able to move further requires a rather radical rethinking of the project, where we replace the Intel Decimal Library with size-optimized decimal code.

As a result, release 0.5.2 will be the last one using the Intel Decimal Library, and is release in parallel with 0.6.0, which switches to a table-free and variable-precisions implementation of decimal code that uses much less code space. The two releases should otherwise be functionally identical

New features

• Shift and rotate instructions (#622)
• Add CompatibleTypes and DetsailedTypes setting to control Type results
• Recognize HP-compatible negative values for flags, e.g. -64 SF (#625)
• Add settings to control multiline result and stack display (#634)

Bug fixes

• Truncate to WordSize the small results of binary operations (#624)
• Fix day-of-week shortcut in simulator
• Avoid double-evaluation of immediate commands when there is no help
• Generate an error when selecting base 1 (#628)
• Avoid Number too big error on based nunbers
• Correctly garbage-collect menu entries (#630)
• Select default settings that allow solver to find solutions (#627)
• Fix display of decimal numbers (broken by multi-line display)
• Fix rendering of menu entries for Fix, Std, etc
• Detect non-finite results in arithmetic, e.g. (-8)^0.3m (#635, #639)
• Fix range-checking for Dig to allow -1 value
• Accept large values for Fix, Sci and Eng (for variable precision)
• Restore missing last entry in built-in units menu (#638)
• Accept Hz and non-primary units as input for ConvertToUnitPrefix (#640)
• Fix LEB128 encoding for signed value 64 and similar (#642)
• Do not parse IfThenElse as a command
• Do not consider E as a digit in decimal numbers (#643)
• Do not parse min as a function in units, but as minute (#644)

Improvements

• Add OnesComplement flag for binary operation (not used yet)
• Add ComplexResults (-103) flag (not used yet)
• Accept negative values for B→R (according to WordSize)
• Add documentation for STO and RCL accessing flash storage
• Mention True and False in documentation
• Rename MaxBigNumBits to MaxNumberBits
• Return HP-compatible values from Type function
• Minor optimization of flags implementation
• Catalog auto-completion now suggests all possible spellings (#626)
• Add aliases for CubeRoot and Hypothenuse
• Align based number promotion rules to HP calculators (#629)
• Expand the range of garbage collector integrity check on simulator
• Show command according to preferences in error messages (#633)
• Avoid crash in debug_printf if used before font initialization
• Update performance data in documentation
• Add ability to disable any reference to Intel Decimal Floating-point library
• Simplify C++ notations for safe pointers (+x and operartor bool())
• Fix link to old db48x project in README.md

Release 0.5.1 "Talents": More RPL commands

This release focuses on rounding up various useful RPL commands and bringing RPL a bit closer to feature-complete.

New features

• Portable bit pattern generation commands, gray and rgb (#617)
• Add support for packed bitmaps (#555)
• Implement RPL case statement, extended with case when (#374)
• Beep command (#50)
• List→ command (#573)
• Size command (#588)
• Str→ command (#590)
• Obj→ command (#596)
• Add flag to control if 0^0 returns 1 or undefined behaviour (#598)
• Unicode-based Num and Chr commands, Text→Code and Code→Text (#597)
• IP and FP commands (#601)
• Percentage operations %, %CH and %T (#602)
• Min and Max operations (#603)
• Floor and Ceil operations (#605)
• Get with a name argument (#609)
• Put command (#610)
• Head and Tail commands (#614)
• Map, Reduce and Filter commands (#613)

Bug fixes

• Ensure rounded rectangles stay within their boundaries (#618)
• Prevent auto-power-off for long-running programs (#587)
• Fix old-style RPL shortcuts for FS?C and the like
• Add FF shortcut for FlipFlag
• Fix rendering of <, >, etc in old-style RPL compatibility mode (#595)
• Update various menus
• Evaluate program arguments in IFT and IFTE (#592)
• Evaluate algebraic expressions in if, while and case (#593)
• Load variables from state file in correct order (#591)
• Avoid truncation of state file when ASCII conversions occur (#589)
• Clear debugging state more completely after kill (#600)
• Wait no longer makes it harder to stop a program (#619)
• mod no longer gives wrong result for negative fractions and bignums (#606)
• No longer strip tags in non-numeric arithmetic operations (#607)

Improvements

• Small updates to demo file
• A long Wait command allows the calculator to switch off (#620)
• Centering of variable names in VariablesMenu (#610)
• Makefile check-ids target to check if commands are in help or menus (#615)

Release 0.5.0: Statistics and flags

This release provides statistics functions and flags.

New features

• Statistics (#495) and linear regression (#569)
• File-based statistics (#571)
• Sort, QuickSort, ReverseSort, ReverseQuickSort and RevList (#572)
• Flags, i.e. CF, SF, FS?, etc (#43)
• Plot scaling commands such as SCALE, CENTR, XRNG, ... (#582)
• Add CurveFilling and DrawPlotAxes setting flags (#580)
• ScatterPlot (#577) and BarPlot (#579)

Bugs

• Save settings enumerations as portable text (#565)
• Avoid infinite loop when reading at end of help file
• Repair behaviour of -1 DIG, broken by settings improvements
• Fix definition of rpm in units and units file
• Crash in list::map when called function errors out (#570)
• Fix editor horizontal movement when inserting commands (#576)
• Repair plotting demo (#583)
• Fix vertical position of axes in DrawAxes (#584)
• Very long drawing loop if ppar axes are backwards (#585)

Improvements

• Sets editor selection correctly for command-line errors
• Ability to parse command and setting names in quotes, e.g. 'Radians'
• Insert command names inside quotes (#575)
• Update documentation of implemented features (#569)
• Make PlotParameters a keyword (#578)

Release v0.4.12: Emergency bug fixes, filesyste, access

A few quick bug fixes related to issues found in 0.4.11.

New features

• STO and RCL to file (#375)
• Parsing of text containing quotes (#562)

Improvements

• Rework file load/save dialog boxes
• Preliminary plumbing for statistics functions

Bugs

• Error loading state files that contain directories (#559)
• Font setting for result was taken from editor font (#560)
• Crash running the Shapes demo (#563)

Release 0.4.11: Debugging, Units, Settings

This release implements debugging, infinite RPL recursion, mixed fractions, customizable units cycling, and restores missing entries in the units menu.

New features

• Allow customization of Cycle for units (#534)
• Allow infinite recursion in RPL code (#537)
• RPL program and expression debugging (#552) including after EXIT
• Mixed fractions such as 1 1/3 (#554)
• BeepOn and SilentBeepOn features (#280)
• ScreenCapture and keyboard shortcut (#434)

Bugs

• Accept 2.3 FIX and #0 Background (#557)
• Do not parse 67.200525 as a decimal32 (#551)
• Bump low battery voltage to 2.550V (#553)

Improvements

• Catalog shows all commands containing typed text (#556)
• Reorganize the units menu (#550) and restore missing units
• Remember menu page for LastMenu (#545)
• SPC key inserts ; when inside parenthese (#499)
• Settings are now entirely defined by ids.tbl (#294)
• Improve user interface code consistency
• Improve GC handling of "just-past-end-of-object" pointers
• Remove the execute() RPL callback, rely on evaluate()
• Optimize allocation of 1-byte vs 2-byte opcodes
• Render abs as abs and not norm (accept norm while parsing)

Release v0.4.10: Performance and units file

This release focuses on display performance optimization and support for unit data files.

New features

• Cycle command for units (#517)
• Possibility to load units from config/units.csv file (#496, #544)
• Internal: debug_printf facility (#541)
• ShowBuiltinUnits and HideBuiltinUnits settings (#542)
• Provide config/units.csv example file (#543)
• Build units menu from units file (#544)

Bugs

• Possible memory corruption in expressions
• Calculator lock-up trying with unit conversions in numeric mode (#529)
• Numerator and divisor no longer truncated to 32-bit (#539)
• Correctly save LastArg for interactive operations (#540)

Improvements

• Optimize the font cache, makes stack drawing faster in SCI mode (#526)
• Add TypeName to object menu (#527)
• Regroup units in units menu by scale (#528)
• Status of implementation and performance data in documentation (#530)
• Performance: Reduce frequency of busy cursor drawing (#531)
• Performance: Reimplement range-based type checkig (#532)
• Performance: Focused -O3 optimizations on DM42 (#533)
• Makefile: Install target installs demo and config (#547)
• Garbage collector for menu labels (#548)

Release 0.4.9 - Support for units

This release focuses on support for units, but also adds a large number of other fixes and improvements.

New features

• Power-off message indicating low-battery situation (#521)
• Add ConvertToUnixPrefix command and SI prefix menu keys (#513)
• Recognize all units that exist in the HP48, and a few more (#491)
• UFACT (FactorUnit) command (#512)
• Unit simplification, e.g. turn 1_m^2*s/s/m into 1_m (#506)
• Converting unity units to numbers (#502)
• →Unit command (#501)
• UnitValue (UVAL) command (#493)
• Implement "kibibytes" (KiB) and power-of-two SI prefixes (#492)
• Unit arithmetic (#481)
• Add B->R and R->B to BasesMenu (#488)
• Implement term reordering capability in rewrite (#484)
• BaseUnits (UBase) command (#483)
• Unit parsing for complex units, e.g. 1_cm^2 (#482)
• Unit arithmetic (#481) including automatic conversions (#480)
• Convert command (#480)
• Implement the Cycle command for unit objects
• Add Å character for angstroem (#477)
• Add Merge state to State system menu (#475)
• Use Unicode font to display the name of a program when executing it (#469)
• Allow incremental search to find digits and Unicode (#468)
• Add tool glyph to user interface font

Bug fixes

• Do not parse symbols beyond input buffer (#524)
• Parse unit menu entries as expressions, not symbols (#523)
• Fix reduced-precision arithmetic (#521)
• Do not parse empty denominator as zero, e.g. 2/s (#520)
• Do not parse a fraction inside a power, e.g. X^2/3 (#519)
• Convert fractions to decimal in numeric mode (#516)
• Do not emit mantissa_error for valid numbers (#515)
• Apply negation correctly on unit objects (#500)
• Do not emit separator after trailing 0 in integer decimals (#489)
• Do not emit extra spacing before decimal separator (#485)
• Fix stack depth in one error case of evaluate_function()
• Fix display of next/previous icons for large menus (#478)
• Clear settings when loading a state (#474)
• Fix separators in whole part of decimal numbers when setting is not 3 (#464)
• Parse (sin x)²+(cos x)² correctly, as well as HP67 Mach example (#427)

Improvements

• Rename equation as expression (#518) and labelText as label_text
• Do not update LastArg except for command line (#511)
• ToolsMenu: Connect units to the UnitsConversionMenu (#514)
• Display unit using / and ·, e.g. 1_m·s^2/A (#507)
• Show units menu for inverse units as mm⁻¹ (#503)
• Display battery level more accurately, i.e. consider 2.6V "low" (#476)
• No longer acccept empty equations or parentheses, e.g. 1+() (#487)
• Make StandardDisplay mode obey MinimumSignificantDigits (#462)
• Add algebraic evaluation function for easier evaluation in C++ code
• Reimplement unit type as a derivative of complex (#471)
• documentation: Use 🟨 and 🟦 for more commands (#467)
• Swap Search and Copy commands in EditorMenu (#466)
• STO stores variables at beginning of directory (#462)
• documentation: Add quickstart guide, used for video recording
• documentation: Add links to YouTube videos
• documentation: Add release notes
• documentation: Some typos and other improvements
• documentation: Rework section on keyboard mappings