The HP-65 was the first programmable handheld calculator in the world. Introduced by Hewlett-Packard in 1974, it was considered an electronic marvel. The HP-65 was tried on backup computations for docking maneuvers on board the NASA Apollo Space Command / Service Module in the Apollo-Soyuz missions in 1975.
Caption: HP-65 It’s programmable! Now comes the world’s first fully programmable pocket calculator: the HP-65. with its own external memory and built-in magnetic card reader.