Support

Questions, problems, ideas: rpn50g@pasahome.org. Please mention the platform (iPhone, iPad, Mac), the OS version and the firmware version shown in About.

Getting started

1. 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.
2. 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.
3. The calculator starts in algebraic mode. For RPN: MODE, choose RPN in the Operating Mode field, OK.

The menu

Tap (or click) the RPN badge at the top right of the calculator: paste text, choose another firmware version, rebuild the SD card from your files, reset the calculator, About. On the Mac the same commands are in the menu bar, with keyboard shortcuts.

SD card and files

• iPhone / iPad: in the Files app, open On My iPhone ▸ RPN 50g ▸ SD Card. Files you put there are placed on the emulated card after Rebuild SD card from Files; files the calculator writes to the card appear in the same folder.
• Mac: File ▸ Mount SD Folder… exposes any folder as the card; 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.
• The card is a FAT16 volume of 64 MB with 8.3 file names, like the real calculator expects.

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.

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.

Open source

The emulation core is released under the MIT licence. HP, HP 49g+ and HP 50g are trademarks of HP Inc.; RPN 50g is an independent project, not affiliated with or endorsed by HP.