RPN vs Calc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RPN
Experience a faithful simulation of the groundbreaking HP-65 programmable calculator on your iPhone. This app offers virtual program and data cards, a paper tape printer, and a robust card manager. Explore four distinct operating modes, including an enhanced "Super-65" option.
- Virtual program and data cards
- Virtual paper tape printer with AirPrint
- Database-driven card manager
- Create, delete, and organize unlimited cards
- Sharing via email, AirDrop, Dropbox, iTunes
- Paste and run existing HP-65 listings
- Four distinct operating modes
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World's first pocket computer! Now running on your iPhone. RPN-65 SD is the iPhone version of RPN-65 Pro, the first complete simulation of Hewlett-Packard's stunning HP-65 programmable calculator for iOS. Produced from 1974 to 1977 at an initial price of $795 (that's close to $5,000 today!), the HP-65 was a breakthrough. Not only was it programmable, it also contained a motorized magnetic card reader - and still fit into Bill Hewlett's shirt pocket. Experience this revolutionary calculator on your iPhone. With over 180 original HP programs included with the app, you can get started right away. "A work of art. Fantastic!" (MacBreak Weekly, episode 572) Features: • Virtual program and data cards • Virtual 2000-line paper tape printer supports AirPrint • Powerful database-driven card manager • Create, delete, label, and organize a virtually unlimited number of cards • Sharing: e-mail, AirDrop, Dropbox, iTunes, copy, paste, print • Paste existing HP-65 listings into RPN-65 and run them • "Live" display of stack, memory registers, program counter, flags • Reads program and data cards created by RPN-65 Pro • Reads data cards created by RPN-67 Pro/SD and RPN-97 Pro Run RPN-65 SD in any of 4 modes: 1 - Just like the original HP-65 2 - Like the original HP-65, but at much higher speed 3 - With many user-interface improvements, like backstep key or jump to any program step 4 - "Super-65" with 999 program steps, 120 labels, 120 registers, nested subroutines, and much more For details, free program downloads, calculator handbook and much more, visit the RPN-65 website: cuveesoft.ch/rpn65
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.
- 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)
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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
Verdict
The clearest difference is price: Calc at Free against RPN's $2.99. Calc also leads on update cadence (every 9 days vs every 4 months). RPN's advantage is ratings volume (8 vs 2) and iOS requirement (12.0 vs 18.0). On rating, review sentiment, ads and in-app purchases 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
Calc is free to download; RPN costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for RPN against 5.0 for Calc. Both are backed by a comparable volume of ratings — 8 and 2 respectively. Written reviews split almost evenly too, at 100% and 100% positive.
RPN ships an update every 4 months, Calc every 9 days. The most recent releases landed on November 2, 2026 and November 9, 2026 respectively.
| Parameter | RPN | Calc |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 5.0 (8 ratings) | 5.0 (2 ratings) |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 8 — better | 2 |
| Update frequency | Every 4 months | Every 9 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 12.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 62 MB | 9 MB |
| Age rating | 4+ | 4+ |
| Developer | CuVee Software | Martin Erzberger |
Customer experience
RPN
Calc
In-app purchases
RPN
No in-app purchases
Calc
No in-app purchases









