Live Reviews:
RPN-55 SD

RPN-55 SD

Classic HP Calculator w/Timer

⭐️5 / 5
Rating
🙌6
Ratings
📼10 scs
Content
📦~ in 3 months
Updates frequency
🗣❌ unsupported
Your locale
Subscribe to price changes:

All Versions of RPN

2.9

January 13, 2024

• Internal optimizations and cleanups. • Modified Info screen to avoid clipping by the Dynamic Island.
More

2.8

December 19, 2023

• Both slide switches may now be operated either by moving them with the finger, or by simply tapping them. • The haptics level may be selected in Settings. • Like on a real HP-55, executing SST on step 00 in RUN mode simply ends any user input value. The next SST will execute step 01. • Runs on Apple Silicon Mac (see notes on homepage cuveesoft.ch). • RPN-55 SD requires iOS 12 or later.
More

2.7.2

January 9, 2023

Like on a real HP-55, executing SST on step 00 simply ends any user input value. The next SST will execute step 01.
More

2.7.1

October 9, 2022

• Fixes a crash when trying to Export a program

2.7

September 29, 2022

• Haptics Set the haptic feedback level in the calculator's settings. „Sounds & Haptics“ / „System Haptics“ must be on in the iPhone's settings. • FileListView can be dragged down
More

2.6

April 9, 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.
More

2.5

October 5, 2021

• Improved sample program "Solve f(x) = 0"

2.4

December 15, 2020

• Improved mail subject when mailing a program as PDF • New sample program "TVM - Solve for i" • Visual feedback when reloading programs in file list view Bug fix: • GSB command could not be pasted as text in PRGM mode
More

2.3

November 8, 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 • Improved accuracy in extreme cases of y^x with positive, integer x. For example, 1.0000001^(2^27) = 674530.4707, not 674530.4760 • New programs: "Nominal vs Effective Rate", "Num. Integration - Gaussian" • 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 • Programs mailed in calculator view incorrectly showed step 00 • Double- or triple-tapping the empty program listing could cause a crash.
More

2.2

September 16, 2020

• n! now appears as x! in advanced mode to reflect the fact that the function can handle non-integer arguments. • Added and updated sample programs. Be sure to tap "Reload Sample Programs" in program list. Bug fixes: • Fixed a bug occurring when single-stepping a programmed number input • Automatic mode switching based on the loaded program didn't work as expected in some cases
More

Price History of RPN

Description of RPN

RPN-55 SD is the first photo-realistic simulation for the iPhone of Hewlett-Packard's low-cost alternative to the famous HP-65 programmable scientific calculator. Produced from 1975 through 1977, it was the "Merlin" member of the classic HP calculator series, priced at $395. HP claimed that it featured "(...) more pre-programmed functions than any other scientific pocket calculator in the world." A main feature of the HP-55 was a crystal-controlled 100-hr digital timer with the ability to store times while the timer was running and later recall them. On RPN-55 SD the timer may also act as a 12-hr or 24-hr clock, including date and weekday display. While the simulator works just like the original calculator – except being much faster and having twice the program memory – you can turn on extended features to make it even more enjoyable to use. RPN-55 SD comes complete with original HP programs built in. Features: • Photo-realistic look-and-feel • Vintage mode or Extended mode • Programmable (99 steps), conditional branching • Insert and delete steps with automatic address correction • Delete range of steps • Subroutines (4 levels) • 20 registers, "continuous", with unrestricted store/recall arithmetic • "Live" register view • Program listing view • Program library view • Store and retrieve any number of programs • 100-hr timer supporting 10 split times and 12/24-hr clock mode with date • Swap unit conversions with additional functions, e.g. hyperbolics • Sharing: e-mail, AirDrop, Dropbox, copy, paste, print • 112 programs pre-installed Calculator functions: • Statistics (linear regression, mean, standard deviation, correlation coefficient, x- and y-estimates) • Trigonometric functions (degrees, radians, grads) • Polar/rectangular conversions • Inverse, square root, logarithm, exponential, pi • Storage arithmetic (store and recall) • Percent, absolute, integer, fractional value, round • Factorial • Random number • Unit and hours conversions Details: cuveesoft.ch/rpn55
Show less

RPN: FAQ

Does RPN work on iPads?

No, RPN does not offer an iPad version.
The app was developed by Willy Kunz.
To function properly, the app requires at least iOS 12.0.
The rating of 5.0 out of 5 that RPN has received from users is outstanding.
The Rpn App Relates To The Productivity Genre.
2.9 is the most recent version of the RPN app.
July 2, 2024 is the date of the latest RPN update.
RPN was introduced to the market on February 6, 2023.
Contains nothing objectionable, appropriate for all ages.
RPN can be used in American English.
No, RPN is not featured on Apple Arcade.
No, RPN does not include options for in-app purchases.
Sorry, RPN is not specifically engineered for compatibility with Apple Vision Pro.

Screenshots of RPN

iphone

More Applications by Willy Kunz

Alternatives to RPN

Reviews of RPN

  • Hyperbolic functions

    In the next update for this calculator please add the six hyperbolic functions. HSIN, HCOS, HTAN, ARCHSIN ARCHCOS, ARCHTAN.
    This is a five star appreciation.
  • Perfect

    Very realistic. A delightful calculator app especially if one doesn’t have a real HP-55 handy.
  • My Calculator of Choice

    The HP 55 was my first scientific calculator. It got me through high school physics and an electrical engineering degree at UC Berkeley. (I used a Pickett N-500-ES slide rule for high school chemistry.) These days, the RPN-55 app is my calculator of choice. It provides all the functions I tend to need, packaged in a way that brings back pleasing memories from decades ago. In terms of function, the standard HP 55 H.MS± functions are surprisingly useful (on occasion), and I don't "Replace Unit Conversions" because I find the unit conversions more nostalgic and useful.

    In a future release, it would great to have the "high contrast mode" feature implemented (such as in RPN-25 CE). You might imagine that my eyes have aged somewhat since my time with the physical HP 55, and any help would be appreciated! Even better would be an HD edition which can display the stack and registers (as in RPN-45 HD).

    But in its current incarnation, RPN-55 is eminently functional and fun to use.