This is the story of the first modern computer program and the extraordinary woman who wrote it, Klara von Neumann.

The program Klara wrote was a list of numbers eight hundred odd lines long. Gibberish to look at now but to the room-sized computer she was working with, it translated into a sophisticated set of instructions telling it how to map out the path neutrons would take inside nuclear bombs.

To mark International Women’s Day we’re going in search of Klara von Neumann and giving her the recognition she so richly deserves.

Dallas’s guest to make this happen is Ananyo Bhattacharya. Ananyo wrote a wonderful book about John von Neumann called The Man from the Future and has championed Klara and her work.

Edited by Stuart Beckwith, Produced by Freddy Chick, Senior Producer is Charlotte Long.