Early Computer Programming

The story of how Joyce Wheeler pioneered programming in the early days of the computer age.

16:23 16 January 2017

In 1949, Edsac – the Electronic Delay Storage Automatic Calculator – was built to serve scientists at the University of Cambridge. The machine is recognised as the first computer ever used and Joyce Wheeler was one of the scientists to use it.

 

She said: "My work was about the reactions inside stars. I was particularly interested in how long main sequence stars stay on their main sequence.

 

"I wanted to know how long a star took to fade out," she explained.

 

She faced many challenges in describing the energetic process that keeps the stars shining.

 

"For stars, there's a rather nasty set of differential equations that describe their behaviour and composition,"

 

"It was not possible to be really accurate doing it by hand," she said. "The errors just build up too much."

 

Edsac was then created by Prof Maurice Wilkes and it was designed to do exactly the kind of calculations Ms Wheeler needed to complete her PhD.

 

As an operator she was allowed to run Edsac alone, provided she signed in and kept a record of what she did.

 

Looking back, she said: "Quite often it would break down during the night, but just occasionally you were lucky enough to keep it running all night. If it did crash, there was little that operators were allowed to do to try to fix it.

 

"They didn't even let any of the cleaners get near it," she said.

 

"We were doing work that could not done in any other way," she said. And even though Edsac was crude and painfully slow by modern standards, she saw that a revolution had begun.

 

"It was clear that one day, when the machines got bigger and faster, a lot of problems would start to be solved."