RPN 50g

The HP 50g is the last and most powerful of a legendary line: HP 48S, 48G, 49G, 49g+ and finally the 50g — a quarter century of RPN and RPL calculators that engineers, physicists and mathematicians never really let go of. Discontinued in 2015, it remains the reference, and many consider it the best calculator ever made.

RPN 50g brings that machine to your iPhone and iPad — not an imitation, the real thing. The app emulates the calculator's hardware (its 75 MHz ARM processor, 512 KB of RAM, 2 MB of flash, the 131×80 display, the keyboard and the SD card slot) and runs HP's original firmware, so it behaves exactly as the calculator on your desk: every function, every mode, every flag, every quirk, key click included.

THE CALCULATOR
• An advanced computer algebra system: exact rational and arbitrary-precision integer arithmetic, symbolic simplification, factoring, polynomials, derivatives, integrals, limits, Taylor series, equation and system solving, linear algebra
• An advanced scientific calculator: complex numbers, vectors and matrices, statistics and regressions, unit conversions with dimensional analysis, base conversions (BIN/OCT/HEX) and bit operations, numeric solver, financial (TVM) calculations, date and time arithmetic
• Graphing: 2D function, polar, parametric, conic, slope field, differential equations, statistics and 3D wireframe/surface plots, with zoom, trace and analysis
• The Equation Library with over 300 equations of physics and engineering, with units
• RPN with the four-level or unlimited stack, or algebraic entry with the equation writer, at your choice
• Programmable in RPL (UserRPL and SysRPL): your programs and libraries run as on the real machine

THE APP
• Firmware versions 2.15 (2009, with the 2 MB fix), 2.10 and 2.09 — switch between them, each keeps its own memory
• Your calculator's memory stays: close the app, come back later, it is exactly where you left it
• SD card: put files in the app's folder in Files and they appear on the calculator's card; what the calculator writes to the card lands in Files. Install libraries as on the real machine
• HP's manuals (User's Guide, Advanced User's Reference…) can be downloaded into the app and read next to the calculator; the app remembers your page
• Paste: type text from the clipboard onto the calculator
• Hardware keyboard support on iPad and iPhone
• The beeper, so BEEP and key clicks sound like the calculator
• Works fully offline, no account, no ads, no tracking

ABOUT THE FIRMWARE
The app contains no HP software. On first launch you pick a firmware version and it is downloaded from hpcalc.org, the community archive that has hosted HP's own update packages for decades, exactly as you would with a browser; the image is then kept on your device.

HP, HP 48, HP 49g+ and HP 50g are trademarks of HP Inc. This app is an independent project and is not affiliated with or endorsed by HP.