RPN-38 CX 4.2 - App Store

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About RPN-38 CX

RPN-38 CX is the first photo-realistic simulation of Hewlett-Packard's popular high-end programmable business calculator HP-38C for the iPhone. Produced from 1979 through 1983, it was the "Chive" member of the...

RPN-38 CX is the first photo-realistic simulation of Hewlett-Packard's popular high-end programmable business calculator HP-38C for the iPhone. Produced from 1979 through 1983, it was the "Chive" member of the third-generation HP calculators known as the "Spice" series. While the simulator works like the original calculator, a number of carefully designed extensions make it a lot easier to use. RPN-38 CX is fully compatible with the HP-12C, except for calculations and programs involving Bonds and Depreciation. Features: . Photo-realistic look-and-feel . Programmable (99 steps, program memory not shared with register memory) . Subroutines, flags, loop control, extended conditional branching . Insert and delete steps with automatic address correction . 20 registers, "continuous", with unlimited store/recall arithmetic . Indirect register addressing . Register view . Program listing view . Program library view . Additional functions (nominal and effective interest rate) . Shortcuts for often-used key combinations . Store and retrieve any number of programs . Sharing: e-mail, AirDrop, Dropbox, copy, paste, print . 40 programs pre-installed Calculator functions: . Percentage (%, ∆%, %Total) . Simple and Compound Interest . Optional odd periods (like HP-12) . Nominal/Effective interest rate conversion . Amortization . Discounted Cash Flow Analysis . Net Present Value, Internal Rate of Return . Date and Calendar (actual or 30/360 day basis) . Statistics (mean, weighted mean, standard deviation) . Linear Regression . Additional functions not found on the HP-38: - Subroutines, flags, loop control, random number, Pi, Log, x² and more Details: cuveesoft.ch/rpn38

Version History • Improved compatibility with iPhone Air and iOS 26. 4.2 10/15/2025 Non-volatile stack: when reloading the app, the stack is now restored along with all registers. 4.1 07/25/2025 • Faster startup – no delay until the first button press is recognized after switching on. 4.0 05/08/2025 • Added warning when attempting to replace a Sample Program. • Visual adjustments to iPhone 16 Pro and iPhone 16 Pro Max 3.9 10/22/2024 • Internal optimizations and cleanups. • Modified info screen to avoid clipping by the Dynamic Island. 3.8 01/15/2024 • Runs on Apple Silicon Macs (see notes on homepage cuveesoft.ch) • RPN-38 CX requires iOS 12.0 or later 3.7 12/23/2023 • Fixes a crash when trying to Export a program 3.6.1 10/09/2022 • Haptics Set the haptic feedback level in the calculator's settings. „Sounds & Haptics“ / „System Haptics“ must be on in the iPhone's settings. • KeyGlow Enable or disable key flashing in the calculator's settings. • Program list view can be dragged down to dismiss it. 3.6 09/28/2022 • Change the program listing font with a simple tap on the new button "F" • Apply a filter to quickly find any program. • Sample Programs may be hidden in the list of programs. Bug fix: • IRR and NPV cash flow calculations produced incorrect results if the group count of the initial investment CF0 was larger than 1. 3.5 04/09/2022 • Improved solving for interest handles extreme cases without iteration error • Address LASTx indirectly via RCi and STi by treating it as register 20 • When executed interactively, ISG and DSE do not change the program counter • CLEAR FIN clears the Compound Interest indicator only when "Use Odd Periods" is off Bug fixes: • Deleting a block of program steps could result in wrongly adjusted branch targets in some cases • ISG/DSE commands were susceptible to internal rounding effects 3.4 12/15/2020 • Print (or mail as PDF) the program or its description • A program running longer than one minute will emit a short beep when executing the final GTO 00 command • Tap f or g, then P/R to see a 12- or 24-hour clock. • Improved accuracy in extreme cases of y^x with positive, integer x. For example, 1.0000001^(2^27) = 674530.4707, not 674530.4760 • New or updated programs: "Trigonometrics", "Gamma Function (Spouge)" • Call up "What's New" anytime from Info screen • Compatibility with iPhone 12 Bug Fixes: • Fixed display issues when using the iPhone in "Zoomed" mode • The RND function didn't work correctly in regions using a comma as decimal point • Double- or triple-tapping the empty program listing could cause a crash. • Setting the haptic feedback level didn't check sufficiently for the correct code 3.3 11/08/2020 • Replaced function π with NOP in top function bar • π is now "g +" • NOP instructions show as LBL if targeted by GTO or GSB • Key flashing may be turned off and on: - Store 19390101 in R1 to turn off - Recall 19390101 from R1 to turn on (Hewlett-Packard Company was founded on Jan 1, 1939) • Haptic feedback may be turned off and on: – Store 1939010X in R0 to set amount of feedback (where X = 0: no feedback, X = 3: maximum feedback) 3.2 09/02/2020 • Register view shows localized formatted value while number is being entered Bug fix: • Using scientific notation could crash the app in some regions, i.e. Australia, Sweden, Slovenia. 3.1 03/20/2020 • Support for iOS 13: Dark Mode, file sharing • Email programs directly from the program list • Replacing registers by pasting a program into the display is now optional • Many under-the-hood optimizations Check out the new Download walk-through on the website (under "Sharing".) Bug fix: • Executing the summation command ∑ with a very large argument would cause a crash RPN-38 CX now requires iOS 11 or later. 3.0 01/25/2020 • New editing commands in programming mode: – DELx,y: delete range of program steps – DELEnd: delete steps from current position to end of program • New program added: "Multiple Linear Regression" • Updated program: "Solve f(x) = 0" • Improved accuracy when solving for interest Bug fixes: • The instruction GSB 90 could not be entered • In some situations, "Error 5" could only be cleared by executing CLR FIN 2.8 08/12/2019 New features: • You can now do register arithmetic using the ∑+ key, e.g. RCL + f ∑+ will add registers R2 and R4 to X and Y, respectively. • Long-press program listing to change font of description from proportional to non-proportional and vice versa. • More detailed descriptions and additional examples in the built-in sample programs. Be sure to execute "Reload Sample Programs". 2.7 07/02/2019 • In addition to exchanging X with register I, you can now use STO I and RCL I with full register arithmetic to register I • Fixed crash on double-tapping GTO nn in program listing when step nn didn't exist 2.6 05/28/2019 • The I-register can now be observed in Register View, formatted for easy interpreting in ISG/DSE commands Bug fixes: • DSE command didn't skip on negative counter values • Storing a value in a regular register, then pressing a financial key would not store the value but execute the function instead 2.5 04/06/2019 • Optional stack display (swipe display right/left) • Indirect addressing of all 20 registers via the I register (on f and g keys) • Improved NOM/EFF operations now use number of periods currently stored in n • Set flags are shown as highlighted register numbers in Register View • Flags are now saved and loaded along with programs • Warning on deleting program memory or program files • On-screen error descriptions • Improved reliability of comparisons • New programs: LogFactorial, Interest/Discount Conversions Bug fixes: • Viewing a program containing any of the commands xw, s, or ∑- would crash the app • Errors didn't always report the correct error number 2.4 02/05/2019 • Improved Program Listing (tap "?" in listing screen) • New buttons at top to select TOP, MID or END of program • Built-in descriptions of extra functions (see Settings) • Pressing R/S shows next command to be executed; releasing R/S starts running program • Cancel R/S by dragging finger from the key • Renamed button "Load" to "Save" • Changed "Undo digit" sound to same as found on other CuVee calculators • Support for late 2018 iPhones Bug fixes: • Layout issue when showing g-shifted keys • Digit separators were not cleared when starting number entry with EEX 2.3 01/09/2019 Bug fix: • Result of DATE operation was not correctly displayed 2.2.2 11/09/2017 • Improved compatibility with iPhone X Bug fixes: • Incorrect app icon shown when installed on iPad • Number number format issues and possible crash when using the EEX key • Top GTO button could not be toggled on and off 2.2.1 11/06/2017 • Improved trig functions for extremely small angles • Support for iOS 11 Bug fix: • Separators didn't disappear when display auto-switched from FIX to SCI mode 2.2 10/24/2017 • New sample program "Prime Factors" added Bug fix: • Examples "Odd Period Example" did not work as shown in description 2.1 09/06/2017 • New program "Polar-Rectangular" (tap "Reload Sample Programs" to see it) Bug fix: • RAND was not programmable 2.0.2 06/07/2017

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Previous Versions

Here you can find the changelog of RPN-38 CX since it was posted on our website on 2016-10-04 05:29:43. The latest version is 4.2 and it was updated on 2026-06-27 04:20:32. See below the changes in each version.

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