RPN 28x Calc3.5.4 - App Store

RPN 28x Calc is a programmable scientific calculator with a pleasingly classic look. Despite its nostalgic appearance, it offers a modern and intuitive user experience, allowing you to interact with your operands by touching them in the display.

It is a reverse-polish notation (RPN) calculator with a dynamic stack display. As you add more values to the stack, the display shown on an iPad automatically expands. To see more lines, simply swipe to scroll. You can also re-order the levels or modify any of the values on the stack.

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"It’s the third RPN calculator I buy for my iPad 2 and the first that makes me happy.
It’s graphically appealing, intuitive and very responsive. I rated it 5 stars."
(Nuno Gomes)

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Advanced commands are available in a secondary panel on iPad or as alternative button pages on iPhone. The buttons are efficiently grouped into five pages that you can quickly access by swiping left or right:

- user-defined buttons,
- letters A-Z for typing,
- trigonometric, logarithmic, and data manipulation commands,
- statistics, storage and programming commands
- binary integers, system flags and boolean logic.

This is why RPN 28x Calc is unique in its class:

- You can tap a row to select it and issue commands for the selected level.
- In REORD mode, it is possible to rearrange the stack by dragging the rows.
- You can swipe up or down the display to see all levels.
- When you enter a value, you can tap a digit to reposition the cursor.
- Tap on the status indicators in the top of the display to change their state.
- Drag buttons to re-arrange them as you like it (enable that in the settings).

Additionally, on iPad:

- The display automatically resizes to show more than just 4 levels of the stack.
- You can slide the secondary panel out of view or swipe across the panel to navigate between button pages.

New:

- 147 scientific units and elementary physical constants.
- Upper-tail probablity distribution commands.
- Interactive program debugging.

RPN 28x Calc is all you need.

- High precision arithmetics.
- Supports multiple data types: real numbers, complex numbers, binary integers, or lists, arrays, vectors, matrices, programs, names, and strings.
- Name your own variables; inspect them in the variable viewer.
- Use the rich command set to write your own programs.
- Create buttons for your programs.
- Interactive button reordering.
- Browse all scientific units and constants in the units viewer.
- View the command history and the results in the log viewer.
- Customizable button click & alert volumes.
- Support for landscape orientation.
- Optional thousand separators.
- Haptic feedback on iPhone.
- External keyboard support.
- Dark Appearance since iPadOS 13 or iOS 13.
- Alternative, dark app icon.
- Use the same app on iPad or iPhone.
- Use the calculator in iPad multitasking, i.e. in a Slide Over view or in Split View.
- No ads, no tracking, and no rating requests.
- Downloadable user guide with introduction and command reference (PDF).

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Plans for future versions (NOT YET SUPPORTED):
- Arithmetic expressions.

Version History - Prevents the assistant window from being hidden whan transitioning from Slide Over or Split View into Full Screen mode.
- Corrects the factorial of zero: 0! = 1. 3.5.4 07/01/2023 - Brings back the nice button titles, especially for the square root title, the A-Z title, and buttons with sigma or arrow characters.

Version 3.5:
- Adds scientific units & constants, double-tap a unit to add it to the stack.
- Unit conversion with CONVERT command.
- The log/variable/units viewer is now also on iPhone.
- Debugging programs: add breakpoints with HALT; use SST to step through the list of commands.
- Adds upper-tail probability distribution commands for the chi-square (UTPC), Snedecor's-F (UTPF), standard normal (UTPS), normal (UTPN), and Student's-T (UTPT) distributions.
...
And more; see version history. 3.5.3 12/12/2022 - Corrects the calculation of n-th roots.

Version 3.5:
- Adds scientific units & constants, double-tap a unit to add it to the stack.
- Unit conversion with CONVERT command.
- The log/variable/units viewer is now also on iPhone.
- Debugging programs: add breakpoints with HALT; use SST to step through the list of commands.
- Adds upper-tail probability distribution commands for the chi-square (UTPC), Snedecor's-F (UTPF), standard normal (UTPS), normal (UTPN), and Student's-T (UTPT) distributions.
- Enhanced the precision for results returned by the SQRT command.
- 0.5 ^ now returns a complex result for negative operands.
- Fixes negative, fractional power calculations.
- New layout for secondary buttons on the A-Z page.
- Fixes an issue when typing commands like PASTE, EDIT or VISIT.
- General improvements. 3.5.2 10/31/2022 - Fixes a crash during button reordering.

Version 3.5:
- Adds scientific units & constants, double-tap a unit to add it to the stack.
- Unit conversion with CONVERT command.
- The log/variable/units viewer is now also on iPhone.
- Debugging programs: add breakpoints with HALT; use SST to step through the list of commands.
- Adds upper-tail probability distribution commands for the chi-square (UTPC), Snedecor's-F (UTPF), standard normal (UTPS), normal (UTPN), and Student's-T (UTPT) distributions.
- Enhanced the precision for results returned by the SQRT command.
- 0.5 ^ now returns a complex result for negative operands.
- Fixes negative, fractional power calculations.
- New layout for secondary buttons on the A-Z page.
- Fixes an issue when typing commands like PASTE, EDIT or VISIT.
- General improvements. 3.5.1 09/29/2022 - Adds scientific units & constants, double-tap a unit to add it to the stack.
- Unit conversion with CONVERT command.
- The log/variable/units viewer is now also on iPhone.
- Debugging programs: add breakpoints with HALT; use SST to step through the list of commands.
- Adds upper-tail probability commands for the chi-square (UTPC), Snedecor's-F (UTPF), standard normal (UTPS), normal (UTPN), and Student's-T (UTPT) distributions.
- Enhanced the precision for results returned by the SQRT command.
- 0.5 ^ now returns a complex result for negative operands.
- Fixes negative, fractional power calculations.
- New layout for secondary buttons on the A-Z page.
- Fixes an issue when typing commands like PASTE, EDIT or VISIT.
- General improvements. 3.5 09/26/2022 - Corrects re-opening the last-used button page.

(Version 3.4 added: complex numbers, a USER page for user-defined buttons, interactive button reordering, and paired statistics commands.) 3.4.1 05/01/2021 - Supports complex numbers!
- Adds a USER page for user-defined buttons.
- Allows interactive button reordering (enable it in the settings).
- New commands: R→C, C→R, RE, IM, CONJ, R→P, P→R, ARG, and SCONJ.
- Adds paired statisitcs: COL∑, CORR, COV, LR, PREDV.
- More. 3.4 04/14/2021 - Adds support for thousand separators.
- Enhanced operand coloring, dimming separators, also in the log (iPad).
- Patches bad results produced by EXP for values below -252.672. 3.3 02/26/2021 - Makes use of a simplified and faster start screen.
- Improves padding of commands entered in alpha mode.
- Removes obsolete code. 3.2.1 09/14/2020 - Eliminates animation conflicts which had caused sluggish button responses.
- The assistant window can now make better use of the available space on large iPads.
- Uses high-precision power function to calculate powers with integer exponents.
- Makes the busy spinner appear white in dark mode.
- Removes the obsolete "Animate All Buttons" setting with which button animations could be disabled.
- Tapping to reposition the cursor in the entry field no longer competes with lingering scroll indicators.
- Corrects selection when finishing editing an entry from a lower stack level. 3.2 05/26/2020 - Adds a dark appearance based on a 50g-inspired color scheme (needs ipadOS 13 or iOS 13).
- Corrects handling of FOR/START...NEXT/STEP loops to allow the use of variables and fractional values.
- Enables haptic feedback on iPhone.
- Extends external keyboard support.
- Offers an alternative, dark app icon.
- Disables some key-press-animations to allow faster typing. Can be re-enabled in the settings.
- Fixes some UI glitches.
- Requires at least ipadOS 12, iOS 12. 3.1 03/16/2020 - Adjusts layout for selected iPhone models.
- Avoids rounding errors when restoring data.
- Corrects the website and email links in the (i)nfo menu. 3.0.2 02/04/2019 - Fixes an issue trying to restore data created by version 2.x.

New in Version 3.0:
- Support for iPhone.
- Programming : Write your own programs and store them in variables.
- Matrices : Arrays in arrays.
- Renames buttons: EDIT -> REORD (reorder), MODIFY -> EDIT.
RPN 28x Calc does not show ads, it does not collect analytics and you will not be prompted for a review.

If you enjoy using the app, please be a star and take a moment to leave a mathematically correct review. To get to the App Store quickly, you can use the "Rate This App" item in the (i)nfo menu from within RPN 28x Calc. 3.0.1 01/17/2019 - Support for iPhone.
- Programming : Write your own programs and store them in variables.
- Matrices : Arrays in arrays.
- Renames buttons: EDIT -> REORD (reorder), MODIFY -> EDIT.

RPN 28x Calc does not show ads, it does not collect analytics and you will not be prompted you for a review.

If you enjoy using the app, please be a star and take a moment to leave a mathematically correct review. To get to the App Store quickly, you can use the "Rate This App" item in the (i)nfo menu from within RPN 28x Calc. 3.0 01/12/2019 - Added an option reduce motion in the startup animation.
- Fixed: The Copy & Paste Shortcut bar will no longer appear, even when Bluetooth is enabled.

Version 2.2

- The display status indicators for LC, SHIFT, (2π), HEX-DEC-OCT-BIN, and STD-SCI-FIX-ENG are now active! You can tap on them to change their state.
- Adjustments for iOS 9.
- Updated icon and launch animation.

RPN 28x Calc will not prompt you for a review. Nevertheless, if you enjoy using the app, please be a star and take a moment to leave a mathematically correct review. To get to the App Store quickly, you can use the "Rate This App" item in the (i)nfo menu from within RPN 28x Calc. 2.2.1 01/08/2016 - The display status indicators for LC, SHIFT, (2π), HEX-DEC-OCT-BIN, and STD-SCI-FIX-ENG are now active! You can tap on them to change their state.
- Adjustments for iOS 9.
- Updated icon and launch animation.

RPN 28x Calc will not prompt you for a review. Nevertheless, if you enjoy using the app, please be a star and take a moment to leave a mathematically correct review. To get to the App Store quickly, you can use the "Rate This App" item in the (i)nfo menu from within RPN 28x Calc. 2.2 12/21/2015 - You can now delete entries from the log.
- Pull up in the log for access to more commands: clear the log, share log items.
- Added ≠ (not equal) command and aliases: CHS, SQRT, and == (equal).
- Corrected the font encoding and added more glyphs.
- Nicer selection colours in the log and variable viewer. 2.1 05/04/2015 Version 2.0.1

- Corrected the comma (,) and period (.) buttons for some locale.
- Improved the operand parsing for numbers larger than 1E128.
- The entries in the command log also use the chosen decimal separator.
- Fixed a crash seen during manual re-ordering.
- Corrected a minor animation glitch at startup.

Highlights in Version 2.0

- New data & command log in a separate notebook window.
- New variable viewer.
- Added COPYN command to copy multiple items.
- More modern fonts used for the buttons.
- Minimum system requirement is now iOS 7.1. Works fine on iOS 8.1.

RPN 28x Calc will not prompt you for a review. Nevertheless, if you enjoy using the app, please be a star and take a moment to leave a mathematically correct review. To get to the App Store quickly, you can use the "Rate This App" item in the (i)nfo menu from within RPN 28x Calc. 2.0.1 03/21/2015 - New data & command log in a separate notebook window.
- New variable viewer.
- Added COPYN command to copy multiple items.
- New SEL and DSEL commands to select and deselect stack levels.
- PASTE now supports arrays, lists, or binary numbers.
- Fixed the POS commands when searching for a 'name' within a "string".
- Changed some commands to store the correct operands for the LAST command.
- More checks for conflicting selections.
- Unearthed some lingering bugs discovered through more rigorous stress testing.
- New interface rendering solution.
- More modern fonts used for the buttons.
- Reduced install size by 30%.
- Internal re-structuring.
- Minimum system requirement is now iOS 7.1. Works fine on iOS 8.1.

RPN 28x Calc will not prompt you for a review. Nevertheless, if you enjoy using the app, please be a star and take a moment to leave a mathematically correct review. To get to the App Store quickly, you can use the "Rate This App" item in the (i)nfo menu from within RPN 28x Calc. 2.0 02/22/2015 Altered secondary views to conform to iOS 8: eMail, Twitter, and settings.
Removed all app rating requests.
Internal redecorations.

RPN 28x Calc will no longer prompt you for a review. Nevertheless, if you enjoy using the app, please be a star and take a moment to leave a mathematically correct review. To get to the App Store, you can use the "Rate This App" item in the (i)nfo menu from within RPN 28x Calc. 1.3.5 11/24/2014 Fixed: The feedback form got the destination email back.
Minor changes under the hood. 1.3.4 08/13/2014 Added rpn28xcalc:// URL scheme to launch the app.
Updated link to online user guide.
General maintainance. 1.3.3 05/16/2014 Fixed: Text alignment in stack view for iOS 6. 1.3.2 01/07/2014 New: A depth counter in top of the stack display.
Fixed: An issue when running iOS 6.1. 1.3.1 11/08/2013 Refined support for iOS 7; it now requires iOS 6.1 or later.
New: Support for external keyboards.
Better: Binary numbers are now edited using the current display type.
Fixed: Trying to MODIFY an empty stack creates an error.
Candy: New app icon, background, updated popup menu. 1.3 11/04/2013