Awesome

hp-mcu-calc

An Arduino library that is an HP-35 emulator. The bulk of this code comes from an Instructables project where enurdag created an Arduino-based HP-35 emulator: https://www.instructables.com/HP-35-Scientific-Calculator-Emulator-With-Arduino-/

If you have an Adafruit MacroPad RP2040 and want to see it working, you can check out this project.

HP 35 calculator links...

• About the HP-35: https://en.wikipedia.org/wiki/HP-35

• A HP-35 simulator (emulator?): https://www.hpmuseum.org/simulate/hp35sim/hp35sim.htm

• Reverse engineering the HP-35 ROM based on a photo of the physical chip - really cool!: http://www.pmonta.com/calculators/hp-35/

• HP Calculator microassembler and simulator: http://www.brouhaha.com/~eric/software/casmsim/ - replaced by https://nonpareil.brouhaha.com

• Some general cool info about the HP-35: https://www.keesvandersanden.nl/calculators/hp35.php

http://home.citycable.ch/pierrefleur/Jacques-Laporte/HP35%20ROM.htm

Other links of interest...

• HP-15c on and ESP32: https://github.com/shezik/esp15c