Is RPN 50g a real HP 50g?

It is a faithful emulator: the app models the calculator's hardware (ARM processor, memory, display, keyboard, SD card slot) and runs HP's original firmware, so every function, mode, flag and quirk behaves as on the physical HP 50g.

Does the app include the HP 50g firmware?

No. On first launch you choose a firmware version (2.15, 2.10 or 2.09) and the app downloads HP's update package (0.8 to 2.4 MB) from hpcalc.org after you confirm; it is then kept on your device.

Does RPN 50g support RPN mode?

Yes. The calculator boots in algebraic mode; MODE lets you switch to RPN, exactly as on the real HP 50g.

Can I transfer files to the calculator?

Yes, through the emulated SD card: files placed in the app's folder (Files app on iOS, a folder you choose on the Mac or on Windows) appear on the card, and files the calculator writes land there — on iPhone, iPad and Mac automatically, both ways.

Where can I get the HP 50g manual?

HP's User's Guide, User's Manual, Quick Start Guide and Advanced User's Reference Manual are free PDFs hosted by literature.hpcalc.org; the support page links to them.

Support

Questions, problems, ideas: info@pasahome.org. Please mention the platform (iPhone, iPad, Mac, Windows), the OS version and the firmware version shown in About.

Getting started

Open the app and pick a firmware version (2.15 is the recommended one). It is downloaded from hpcalc.org and kept on the device.
The calculator boots and asks Try To Recover Memory? — press F6 (NO), then F6 again (OK) on Memory Clear. This is what a real HP 50g does after a memory reset.
The calculator starts in algebraic mode. For RPN: MODE, choose RPN in the Operating Mode field, OK.

Manuals

HP's own documentation for the calculator, hosted by literature.hpcalc.org (PDF). The app can download them for you (menu → Manuals…) and shows them next to the calculator, remembering the page you were reading; the links below open the same files in your browser:

Four documents, in reading order — they overlap on purpose, each one going deeper than the previous:

Quick Start Guide — 60 pages, 1 MB. Start here: the keyboard, the stack, RPN vs algebraic entry, first calculations, a first plot.
User's Manual — 180 pages, 5 MB. The essentials of every feature; it is the printed book that came in the box.
User's Guide — 900 pages, 10 MB (French edition). The complete reference, chapter by chapter (modes, algebra, CAS, calculus, matrices, graphics, statistics, units, programming…) with worked examples. Everything the User's Manual summarises, in full.
Advanced User's Reference Manual — 700 pages, 4.5 MB. For programmers and power users: every command in alphabetical order with its stack diagram, RPL programming, system flags, error messages, the Equation Library.

RPN 48 (HP 48GX / HP 48SX)

The same support address covers RPN 48. Getting started: open the app, pick a model — HP 48GX, ROM revision R is the one to choose unless you want the 48SX — and confirm the download (about 320 KB, from hpcalc.org, where HP allowed the HP 48 ROMs to be published in 2000). The calculator boots and asks Try To Recover Memory?: press F (the sixth menu key, NO). The HP 48 starts in RPN; the RPN badge at the top left (a right-click or F10 on Windows) opens the menu (ROM, manuals, reset, about). Each ROM keeps its own memory.

HP 48 manuals

HP's own documentation for the 48G series, hosted by literature.hpcalc.org (PDF); the app downloads them for you (menu → Manuals…) and shows them next to the calculator:

HP 48G Series Quick Start Guide — 70 pages, 4.5 MB (also in Spanish). Start here: the keyboard, the stack, first calculations and plots.
HP 48G Series User's Guide — 600 pages, 29 MB (Spanish, Portuguese). The complete reference, chapter by chapter, with worked examples; most of it applies to the 48SX too.
HP 48G Series Advanced User's Reference — 600 pages, 76 MB, a community scan. For programmers: every command with its stack diagram, RPL programming, flags, error messages.
For the 48SX specifically: the HP 48 Owner's Manual (a large scan, 109 MB).

RPN 49G (HP 49G)

The same support address covers RPN 49G. Getting started: open the app and confirm the download of HP's ROM package (ROM 2.10, about 2.4 MB, from hpcalc.org); it is checked against its known fingerprint and kept on the device. The calculator boots and asks Try To Recover Memory?: press F6 (NO), then F6 again (OK) on Memory Clear. The HP 49G starts in algebraic mode; for RPN, press MODE, choose RPN in the Operating Mode field and OK. The RPN badge on the case opens the menu: Choose ROM…, Manuals…, Flat Display, Reset calculator, About…. The calculator's memory, flash and port 2 included, is kept when the app is closed.

HP's manuals for the 49G, which the app downloads for you: the Pocket Guide, the User's Manual (also in Spanish, Portuguese and German) and the Advanced User's Guide.

RPN 12C (HP 12C)

The same support address covers RPN 12C. There is nothing to download: the calculator was written from its owner's handbook, contains no HP software and needs no ROM, so it is ready at first launch. The RPN badge at the top right opens the menu; Back Plate turns the calculator over, to its reference table of keystrokes, and a tap on the back turns it face up again.

Memory: as on the calculator, everything is kept when the app is closed (Continuous Memory). ON with − held clears it (“Pr Error”); ON with . held switches between the decimal point and the decimal comma. Both are also in the menu (Clear Continuous Memory…, Decimal Comma).
Keyboard: digits, + − × ÷, the point or the comma, Return = ENTER, Backspace = CLx, Escape = ON, F and G = the prefix keys, S = STO, R = RCL, N = n, I = i, P = PV, M = PMT, V = FV, C = CHS, E = EEX, Y = yˣ, % = %, X = x≷y, D = R↓.
Copy and paste: Paste Numbers (⌘V on the Mac) keys in the numbers of the clipboard, ENTER between two; Copy Number (⌘C) takes X with all its digits.

RPN 15C (HP 15C)

The same support address covers RPN 15C. As with RPN 12C there is nothing to download: the calculator was written from its owner's handbook, contains no HP software and needs no ROM. The RPN badge at the top right opens the menu; Back Plate turns the calculator over, to its reference table (the error messages, the MATRIX and TEST numbers, the statistics registers), and a tap on the back turns it face up again.

Memory: as on the calculator, everything is kept when the app is closed (Continuous Memory). ON with − held clears it (“Pr Error”); ON with . held switches between the decimal point and the decimal comma. Both are also in the menu (Clear Continuous Memory…, Decimal Comma).
Keyboard: digits, + − × ÷, the point or the comma, Return = ENTER, Backspace = ←, Escape = ON, F and G = the prefix keys, S = STO, R = RCL, C = CHS, E = EEX, Q = √x, Y = yˣ, I = 1/x, X = x≷y, D = R↓.
Copy and paste: Paste Numbers (⌘V on the Mac) keys in the numbers of the clipboard, ENTER between two; Copy Number (⌘C) takes the real part of X with all its digits.

RPN 17bII+ (HP 17bII+)

The same support address covers RPN 17bII+. There is nothing to download to start: the calculator was written from its user's guide, contains no HP software and needs no ROM, so it is ready at first launch. The RPN badge on the case opens the menu: Manuals…, Flat Display, Erase Memory…, About….

Entry: ALG or RPN: the MODES menu, as on the calculator.
Memory: as on the calculator, everything is kept when the app is closed (Continuous Memory); Erase Memory… in the menu clears it.
Manuals: HP's the Quick Start Guide and the User's Guide (English, French, German, Spanish, Italian, Portuguese), downloaded on request from literature.hpcalc.org and read next to the calculator (menu → Manuals…).

RPN 32sII (HP 32SII)

The same support address covers RPN 32sII. There is nothing to download to start: the calculator was written from its owner's manual, contains no HP software and needs no ROM, so it is ready at first launch. The RPN badge on the case opens the menu: Manuals…, Flat Display, Erase Memory…, About….

Memory: as on the calculator, everything is kept when the app is closed (Continuous Memory); Erase Memory… in the menu clears it.
Manuals: HP's the Owner's Manual (English, Spanish, Portuguese; German and Dutch scans), downloaded on request from literature.hpcalc.org and read next to the calculator (menu → Manuals…).

RPN 35s (HP 35s)

The same support address covers RPN 35s. There is nothing to download to start: the calculator was written from its user's guide, contains no HP software and needs no ROM, so it is ready at first launch. The RPN badge on the case opens the menu: Face (Matte or Bright), Manuals…, Flat Display, Erase Memory…, About….

Entry: RPN or ALG: MODE, as on the calculator.
Memory: as on the calculator, everything is kept when the app is closed (Continuous Memory); Erase Memory… in the menu clears it.
Manuals: HP's the Quick Start Guide and the User's Guide (English, French, German, Spanish, Italian, Portuguese), downloaded on request from literature.hpcalc.org and read next to the calculator (menu → Manuals…).

The menu

Tap (or click) the RPN badge at the top right of the calculator: paste text, choose another firmware version, reset the calculator, About. On the Mac the same commands are in the menu bar, with keyboard shortcuts. On Windows, right-click the calculator (or press F10) for the same menu; the manuals are under Read the Manual (Ctrl+H).

SD card and files

iPhone / iPad: in the Files app, open On My iPhone ▸ RPN 50g ▸ SD Card. The folder and the card follow each other, automatically and both ways: a file you put there appears on the card (port 3) within a couple of seconds, files the calculator writes appear there, and a file deleted on one side goes from the other.
Mac: File ▸ Mount SD Folder… exposes any folder as the card, kept in step with it both ways as on the iPhone; Mount ROM Package as SD mounts the firmware's own libraries (Equation Library) so that you can install them with the Filer, exactly as on the real machine.
Windows: Mount SD Folder… (Ctrl+M) in the menu exposes any folder as the card; Mount ROM Package as SD (Ctrl+L) mounts the firmware's own libraries, Unmount (Ctrl+U) releases the folder.
The card is a 64 MB FAT16 volume. The calculator shows 8.3 names: a file called “Prog copy.hp” appears as PROGCOPY.HP on the calculator and keeps its full name in the folder.

Keyboard

With a hardware keyboard: letters, digits and operators type on the calculator; Return = ENTER, Backspace, arrows, Escape = ON/CANCEL, F1–F6 = the soft keys, Tab = ALPHA, Control = left shift, Option = right shift. On Windows: F7 = left shift, F8 = right shift, F9 = ALPHA, Escape = ON, F12 = reset, Ctrl+V pastes text, Ctrl+C copies the screen as an image, Ctrl+plus/minus/0 zooms.

Windows

RPN 50g and RPN 48 for Windows come from the Microsoft Store (RPN 48), for Windows 10 version 2004 and later and Windows 11, native on x64 and Arm64 PCs. The calculator is a frameless window: drag it anywhere, minimise or close it with the – and × at the top right of the case, zoom it with Ctrl+plus/minus. The firmware, the calculator's memory, the manuals and the settings live in the app's data folder (%LOCALAPPDATA%\RPN50g or %LOCALAPPDATA%\RPN48, redirected into the app's package storage); uninstalling the app removes them. Saved states are not interchangeable between the x64 and Arm64 builds.

Frequently asked

Is my memory kept when I close the app? Yes. The whole machine state is saved when the app goes to the background and restored on the next launch, per firmware version.

Why does the first launch need a download? The firmware belongs to HP; the app does not ship it. It fetches HP's update package from hpcalc.org, the way you would with a browser, and extracts the image. Nothing else is ever downloaded.

Can I use my own firmware image? The three versions on hpcalc.org are the ones the app knows. If you need another one, write to support.

The calculator seems stuck. As on the real machine, ON+F3 is a warm start and Reset calculator in the menu is the equivalent of the reset hole under the calculator. Neither loses the installed firmware.

Sound? The beeper is emulated (BEEP, key click, error beeps). On iPhone it follows the silent switch; flag −56 on the calculator disables the key click, as on the real one.

Trademarks

HP, HP 49g+, HP 50g, HP 12C and HP 15C are trademarks of HP Inc.; RPN 50g, RPN 12C and RPN 15C are independent projects, not affiliated with or endorsed by HP.