RPN-38 CX — The first photo-realistic HP-38 simulator for the iPhone


Version 3.8

RPN-38 CX is a photo-realistic simulation of Hewlett-Packard's third-generation programmable financial calculator HP-38C.

Released in 1978/79, the HP-38C and HP-38E were the high-end business members of the so-called "Spice" series. The HP-38E was introduced first, followed a year later by the HP-38C which added continuous memory. They were discontinued in 1981 and 1983, respectively.


Features





















Settings


Tap the wrench symbol or double-tap the display to access the
settings screen:
















iPhone 6 Screenshot:






 

 

Version History RPN-38 CX


3.8 – Jan 15, 2024

  • Internal optimizations and cleanups
      New sample programs are now automatically loaded when opening the list of programs.
      Changed the default font for program listings from Courier New to Menlo.

  • Modified the info screen to avoid clipping by the Dynamic Island.

3.7 – Dec 23, 2023
  • New:
  • • Runs on Apple Silicon Macs (Notes)

3.6.1 – Oct 9, 2022
  • Bug Fix:
  • • Exporting a program would cause a crash

3.6 – Sep 28, 2022
  • New:
  • • Set the haptics feedback level in the Settings
  • Key Glow: enable or disable flashing of tapped keys

3.5 – Apr 9, 2022
  • New:
  • • Change the program listing font with a simple tap on the button F
  • • Sample Programs may be hidden in the list of programs
  • • Apply a filter to quickly find any program

  • Bug Fix:
  • • IRR and NPV cash flow calculations produced incorrect results if the group count of the initial investment CF0 was larger than 1

3.4 – Dec 15, 2020
  • New:
  • • Improved Solve for Interest function handles extreme cases.
  • • 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:
  • • ISG/DSE commands were susceptible to internal rounding effects
  • • Deleting a block of program steps could result in wrongly adjusted branch targets in some cases

3.3 – Nov 8, 2020
  • New:
  • • Print (or mail as PDF) the program or its description.
  • • A program running longer than 1 minute will emit a sound when finished (by GTO 00).
  • • 12- or 24-hr clock (by tapping f or g, followed by P/R)
  • • Improved accuracy in extreme cases of yx with positive, integer x.
  • • Call up "What's New" anytime from Info screen

  • Bug Fixes:
  • • Display issues when operating the iPhone in "Zoomed" mode
  • • RND didn't work correctly in regions using comma as decimal point
  • • Double- or triple-tapping the empty program listing area caused a crash

3.2 – Sep 2, 2020
  • New:
  • • Replaced function π with NOP in top function bar
  • • π is now located on the "+" key
  • • 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)
  • Storing other values in these registers doesn't change the settings.

3.1 – Mar 20, 2020
  • New:
  • • 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

3.0 – Jan 25, 2020
  • New:
  • • 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
  • • iOS 11 or later

  • Bug Fixes:
  • • Executing the summation command ∑ with a very large argument would cause a crash

2.8 – Aug 12, 2019
  • New:
  • • New editing commands in programming mode:
      – DELx,y (= f DEL) deletes range of program steps
      – DELEnd (= g DEL) deletes all steps from current position to end of program
  • • New program added: "Multiple Linear Regressions"
  • • Updated program: "Solve f(x) = 0"
  • • Improved accuracy when solving for interest
  • • Renamed "x=0", "x=y", etc. to "x=0?", "x=y?" in listings
  • • Added error 9 ("Iteration Error")

  • Bug Fixes:
  • • The instruction GSB 90 could not be entered
  • • In some situations, "Error 5" could only be cleared by executing CLR FIN

2.7 – July 2, 2019
  • New:
  • • Added full register arithmetic support for ∑+ (acting on registers R2,R4 and X,Y)
  • • 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.

2.6 – May 28, 2019
  • New:
  • • Added instructions STO I and RCL I with full register arithmetic support

  • Bug Fix:
  • • Crash on double-tapping GTO nn in program listing when step nn didn't exist

2.5 – Apr 6, 2019
  • New:
  • • 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

2.4 – Feb 5, 2019
  • New:
  • • 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 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 dialog 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 x̅w, s, or ∑- would crash the app
  • • Errors didn't always report the correct error number

2.3 – Jan 9, 2019
  • New:
  • • 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 off 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

2.2.2 – Nov 9, 2017
  • Bug Fix:
  • • Result of DATE operation was not correctly displayed

2.2.1 – Nov 6, 2017
  • New:
  • • Improved compatibility with iPhone X

  • Bug Fixes:
  • • Incorrect app icon shown when installed on iPad
  • • Number format issues and possible crash when using the EEX key
  • • Top GTO button could not be toggled on and off

2.2 – Oct 24, 2017
  • New:
  • • Improved trig functions for extremely small angles
  • • Support for iOS 11 and iPhone X

  • Bug Fix:
  • • Separators didn't always disappear when changing display mode to SCI or ENG

2.1 – Sep 6, 2017
  • New:
  • • Sample program "Prime Factors" added

  • Bug Fix:
  • • Examples "Odd Period Example" did not work as shown in description

2.0.2 – June 7, 2017
  • Bug Fix:
  • • RAND could not be programmed

2.0.1 – May 23, 2017
  • Bug Fixes:
  • • Pi didn't auto-lift the stack
  • • RND didn't work correctly on certain values
  • • Deleting steps caused wrong address corrections in some cases

2.0 – Apr 26, 2017
  • New:
  • New commands:
      Real subroutines with 4 levels of nesting
      Loop control
      10 flags
  • • 10 comparison commands added
  • • New operations: x², LOG, π, RAND (random number)
  • • CLEAR ALL is now programmable

1.5 – Feb 27, 2017
  • New:
  • • Better FRAC results for large arguments
  • • Program added: "Easter Date"

  • Bug Fix:
  • • RND is now ignored if SCI display format is active

1.4 – Oct 2, 2016
  • New:
  • • Easter date for 1583 thru 4099: set y = 0, x = year, execute DATE
  • • New command "D.MY/BEGIN?" to read mode switch. Tap "f", then mode switch to program.
  • • Calculator sounds mix with background audio and have their own volume control

1.3 – July 26, 2016
  • New:
  • • Pause activity is shown in main and register view
  • • Decimal addition/subtraction for higher precision

1.2 – June 3, 2016
  • New:
  • • Register view gets updated while a program is running
  • • Run/stop and single-step program without leaving register view
  • • Added copy of actual display to register view
  • • LastX may be used in register arithmetic operations, e.g. RCL + ENTER
  • • Tapping any key stops program execution
  • • SST and BST may be cancelled by dragging finger off key
  • • Shared programs include calculator settings and registers
  • • Improved handling of values pasted as text
  • • Improved address correction when deleting program steps
  • • Support for uncommon number groupings (e.g. India)

  • Bug Fixes:
  • • Fixed x ≤ y function involving very large numbers
  • • Fixed automatic target correction of GTO command at end of program memory
  • • Fixed an issue where RCL g R/S in some cases would not find a solution
  • • Fixed wrong key codes for g-shifted functions in bottom row
  • • Statistical functions didn't lift the stack correctly
  • • Text correction in sample program "Trigonometric Functions"
  • • Entering too many digits was not properly handled
  • • Self-check doesn't clear LASTx value anymore

1.1 – March 22, 2016
  • New:
  • • Support for odd-period calculations using simple or compound interest (like HP-12C)
  • • Guesses for IRR solutions may now be entered using RCL g R/S (see HP-38 manual)
  • • Registers, display format, mode switch setting, and odd-period flag are saved with programs
  • • Program loading sets display format, mode switch, and odd-period flag
  • • The setting of the mode switch is programmable
  • • Registers may be preset by pasting multi-line text into the display
  • • Current program step is shown below display. Tap to show or hide.
  • • In program mode, progress bar shows fill status of program memory
  • • User programs are listed separatedly from sample programs

  • Bug Fixes:
  • • GTO statements pasted into the display as text are handled correctly
  • • f 9 (to set 9 decimal digits) is now programmable
  • • GTO 25 was not programmable
  • • Fixed ∑- function producing error message
  • • Fixed sign conventions of simple interest function
  • • Fixed a number of stack-lift issues
  • • FV doesn't show as PV anymore
  • • Fixed crash on storing illegal counter value or using illegal register
  • • Fixed a possible crash on NPV and IRR calculations

1.0 – February 18, 2016
  • First public version.
 

 

RPN-38 CX is available here:

RPN-38 CX

 

 

Looking for a manual?


Owner's Handbook
 

HP-38E/38C
Quick Reference Card
 

Manual do Proprietário
 
 

 

Get RPN-38 CX and its sister app RPN-32 CE at a bargain:

The Spice Pac

 


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