HP-41 Calculator Emulator in Rust: How to faithfully rebuild a classic

3 days. 8 phases. 13,399 lines of Rust. And a calculator from 1979 that once again feels just like the original.

The HP-41C: a legend

Anyone who was an engineer, scientist or pilot in the 1980s knows it: the HP-41C. Introduced by Hewlett-Packard in 1979, it was the world’s first alphanumeric, programmable calculator — expandable through modules, networkable via a special interface, and the calculating machine of choice for NASA astronauts.