Comparison

RPN vs Calc

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

RPN

This app is a faithful simulation of a legendary 1970s programmable calculator, offering advanced features for scientists and engineers. It allows users to run existing programs, manage virtual program cards, and even print listings, all on their iPad.

Highlights
  • Virtual program and data cards
  • Virtual paper tape printer
  • Database-driven card manager
  • Save card collections to Mac/PC
  • Formatted program listings
  • Print listings via AirPrint
  • Live display of stack and registers
Features
Read full description

A dream calculator of the 70's, priced at $1,900 in today's dollars, now on your iPad! RPN-67 Pro is the first complete simulation of Hewlett-Packard's legendary HP-67 programmable calculator for iOS. Produced from 1976 to 1982, the HP-67's features coupled with its capability to store programs on magnetic cards made it a huge success among scientists, engineers and other professionals. Thousands of programs were written for it. Now you can run them right on your iPad, with more ease and faster than ever before. To get you started quickly, download hundreds of program cards from our website for free. What users said: "I am a collector of HP emulators on my iPad. The HP-67 is beyond spectacular!" "What an application! Perfect visual experience, perfect emulation, even the clicks are pleasant." "In many ways, the app is even better than the original - much faster, better and easier programming". RPN-67 Pro is fully compatible with RPN-97 Pro, its companion simulator of the HP-97 calculator. Features: • Virtual program and data cards • Virtual paper tape printer supports all HP-97 printer modes • Powerful database-driven card manager • Create, label, and organize a virtually unlimited number of cards • Use iTunes to effortlessly save entire card collections on your Mac/PC • Sharing: e-mail, AirDrop, Dropbox, copy, paste, print • Formatted listing clearly showing labels and targets of branches • E-mail listings and let the recipient paste the text right into RPN-67 • Print listings on any AirPrint-compatible printer • Program listing on paper tape shows subroutine nesting • Edit paper tape • E-mail paper tape, or print it via AirPrint • Cut/copy/paste displayed value or program steps • Paste existing HP-67 or HP-97 listings into RPN-67 and run them • "Live" display of stack, memory registers, program counter, flags • Show program usage notes • 30 selectable background images, even add your own • Fast: 0.8 secs vs. 6 mins (iPad Pro vs. HP-67, determinant of 5x5 matrix) • Low-battery indicator (iPad charge 10% or less) • Compatible with RPN-67 SD and RPN-97 Pro, CuVee Software's HP-97 simulation • Supports external hardware keyboard While RPN-67 Pro works like a real HP-67, changing a simple setting will turn the app into a super-charged HP-67: • Up to 999 program steps, 8 subroutine levels, 6 additional flags (F4...F9) • 100 additional registers • 100 additional labels • 100 built-in constants and conversions • More than 150 additional powerful operations and functions Plus: • 15 commands to print and manipulate any range of extended registers • Unrestricted register arithmetic • Exchange x with any register • Complex numbers, hyperbolic functions • Non-volatile memory - stack, registers, program, flags, paper tape • Status indicators for prefix keys (f, g, h, STO, RCL, etc.) • Display showing thousands separators (optional) • Text output on paper tape in 10 colors, even simple plotting • Stack-of-stack: push/pop the entire stack on internal stack (4 levels) • Single-step into subroutines (optional) • Powerful debugging aids, including 10 breakpoints with counters • Keycodes translated to command name while entering or single-stepping a program • Change the duration of the PAUSE command • Cancel SST or BST operation by simply sliding your finger off the depressed key • Compress constants in programs into a single step (reversible) • Use existing programs in text format by a simple paste operation RPN-67 Pro comes with more than 130 programs pre-installed, including HP Standard Pac, HP Business Decisions Pac, HP Math Pac I, HP Stat Pac I, and HP Surveying Pac I. The simulator has been verified to correctly run the examples given in HP Civil Engineering Pac I, HP Clinical Lab Pac, HP E.E. Pac I, HP Games Pac I, HP M.E. Pac I, HP Navigation Pac I, as well as large number of programs published in Users' Library Solutions. For more information and free program downloads visit the RPN-67 website: cuveesoft.ch/rpn67

About

Calc

This app emulates the classic TI-59, TI-58, and TI-58C calculators with cycle-accurate precision. It includes features like a virtual magnetic card reader, a PC-100C printer, and a CPU-level debugger for in-depth analysis. Explore old programs or learn how these vintage machines operated.

Highlights
  • Cycle-accurate TI-59, TI-58, TI-58C emulation
  • Virtual magnetic card reader
  • PC-100C printer emulation
  • CPU-level debugger
  • Solid State Software module support
  • State file loading (.ti59, .ti58c)
Features
Read full description

Calc-U-59 is a TI-59, TI-58, and TI-58C emulator for iPhone, iPad, and Mac. It runs the original ROM, so every program, module, and quirk works exactly as it did on the real hardware — with virtual magnetic cards, a PC-100C printer, all fourteen Solid State Software modules, and a CPU-level debugger for anyone who wants to look under the hood. CYCLE-ACCURATE EMULATION The TMC0501 processor is emulated at the cycle level, reproducing the exact behaviour of the original hardware — including the TI-58C's constant memory, preserved across restarts. The Master Library ROM and many more modules are included. INTEGRATED DEBUGGER Inspect program memory, data registers, CPU state, and internal SCOM registers live as the machine runs. Step through instructions one at a time, or let the emulator run and freeze it at any point. You can even run your own assembly programs! On iPad in landscape and on the Mac it sits beside the calculator; on iPhone and in portrait, turn on the debugger page in Settings. PAPER TAPE PRINTER A functional recreation of the PC-100C thermal printer with dot-matrix font rendering. Trace exactly what programs print and why. Copy output as plain text or as a high-resolution bitmap. MAGNETIC CARD READER Load and save programs and data registers as card files, stored on your device and synced via iCloud. Bring old listings back to life and run them under the debugger. STATE FILES Load .ti59 and .ti58(c) state files to instantly configure the machine with a program, registers, and flags — ideal for sharing reproducible scenarios or revisiting known machine states. SOLID STATE MODULES Select a Solid State Module and run programs from there. QUIRKS The calculator reproduces every quirk you've heard of: Fast mode, printer interrupt, display corruption — you name it. Whether you're bringing an old program back to life, running the Master Library modules, or exploring how these machines actually worked under the hood, Calc-U-59 gives you a faithful TI-59 in your pocket. Calc-U-59 is free software under the GPLv3; the source code is on GitHub.

Screenshots

Calc4 screens

Verdict

The call

The clearest difference is price: Calc at Free against RPN's $4.99. Calc also leads on rating (5.0 vs 4.3) and update cadence (every 9 days vs every 3 months). RPN's advantage is ratings volume (6 vs 2) and iOS requirement (12.0 vs 18.0). On ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Calc is free to download; RPN costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Calc holds the better App Store score, 5.0 against 4.3. Both are backed by a comparable volume of ratings — 6 and 2 respectively. Written reviews point the same way: 90% of RPN's written reviews are positive against 100% of Calc's.

UpkeepUpdate frequency

RPN ships an update every 3 months, Calc every 9 days. The most recent releases landed on November 4, 2026 and November 9, 2026 respectively.

Scorecard7 real differences · 3 level
RPN versus Calc: the parameters behind the verdict, then further details
ParameterRPNCalc
Price$4.99Free — better
Rating4.3 (6 ratings)5.0 (2 ratings) — better
Positive reviews90.0% of reviews100.0% of reviews — better
Number of ratings6 — better2
Update frequencyEvery 3 monthsEvery 9 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidFree — better
DevicesiPadiPhone, iPad — better
Requires iOS12.0 — better18.0
Further details — not scored
Size78 MB9 MB
Age rating4+4+
DeveloperCuVee SoftwareMartin Erzberger

Customer experience

RPN

All ratings6 ratings
Positive83.3%
Neutral0.0%
Negative16.7%
Written reviews20 reviews
Positive90.0%
Neutral0.0%
Negative10.0%

Calc

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

RPN

No in-app purchases

None

Calc

No in-app purchases

Questions

Is RPN free?
RPN costs $4.99, with no in-app purchases.
Is Calc free?
Calc is free to download, with no in-app purchases.
Which has better reviews, RPN or Calc?
Calc is rated higher. RPN averages 4.3 out of 5 from 6 ratings, while Calc averages 5.0 from 2 ratings.
Do RPN or Calc have ads?
Neither RPN nor Calc shows ads.
Which is updated more often, RPN or Calc?
RPN ships an update every 3 months, and Calc every 9 days. Most recently, RPN was updated on November 4, 2026 and Calc on November 9, 2026.

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