They haven’t been produced in decades, but [Chris Chung] has used some open source code to create DIY hardware version of the HP-41 Reverse Polish Notation (RPN) calculator. The open source code ...

If you like Nixie tubes and/or DIY calculators, checkout this interesting talk from the HP Handheld Conference in Orlando last month by [Eric Smith] from Brouhaha and [John Doran] from Time ...

The CG-35 is a CircuitPython powered HP-35-like RPN calculator for the Adafruit ESP32-S3 Feather and 3.5-inch TFT FeatherWing display with capacitive touch. The calculator consists of a 10-digit LED ...

The hardware is inspired by the SwissMicros DM42 calculator (which itself mimics the famous HP-42), but designed from scratch. Firmware-wise, however, there is no intention to simulate programmable HP ...