RPN 50g
The HP 50g, on your iPhone, iPad and Mac.The real thing — HP's own firmware, on emulated hardware.
RPN 50g emulates the calculator's processor, memory, display, keyboard and SD card slot and runs HP's original firmware. Everything works exactly as on the machine: RPN and algebraic modes, the CAS, matrices, plots, libraries, UserRPL and SysRPL programs — key click included.
What you get
The complete HP 50g
Pixel for pixel, with the full keyboard. Not a look-alike: the emulated ARM machine runs HP's firmware, so every function, mode, flag and quirk is there.
Three firmware versions
2.15 (2009, with the 2 MB fix), 2.10 and 2.09. Switch between them; each keeps its own memory.
Memory that stays
Close the app, come back later: the calculator is exactly where you left it, like the real one on your desk.
SD card
Files you put in the app's folder (Files on iOS, Finder on the Mac) appear on the calculator's card, and what the calculator writes lands there. Install libraries such as the Equation Library as on the real machine.
Paste and hardware keyboard
Type text from the clipboard onto the calculator; use a keyboard on iPad, iPhone and Mac.
Offline, private
No account, no ads, no tracking, no data collection. Works fully offline once the firmware is on the device.
In use
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. The emulation core was written from the ARM and Samsung reference manuals and is released under the MIT licence.