Work on the Electronic Display Storage Automatic Calculator, or EDSAC, began in 1946, shortlyafter the end of World War II. This behemoth, room-­filling computer, consisting of stacks of shelves of neatly arranged valves and wires, looked nothing like the handheld calculators of today.

In fact, EDSAC’s stacks looked more like an old-fashioned abacus, but what the machine did, was something unprecedented.

Built at the University of Cambridge Mathematical Laboratory, EDSAC’s stacks of valves were designed to take multiple sets of complex data, and perform calculations which far exceeded the capabilities and speed of people with mechanical calculators.

This allowed researchers to solve complex equations in a fraction of the time previously needed, and granted the freedom which led several Cambridge scientists to Nobel Prizes (two in chemistry, one in medicine.)

Unprecedented control over complexity

Until EDSAC, if you had a bunch of complicated equations which you needed to solve, the only options were to use a mechanical calculator, or to painstakingly write out your equations the old-fashioned way. Human error and the inevitable difficulties of trying to reconcile lots of different, very complex equations, presented very real, very limiting problems. EDSAC was logical, you couldn’t distract it, and barring the occasional intervention from a skilled engineer, it didn’t get tired.

EDSAC allowed researchers from all areas unprecedented levels of control over the most complex mathematical problems they were facing. ‘All areas’ is important, too. In theory, anyone could be trained to use EDSAC, meaning that its use wasn’t limited to times when a sole, all-powerful operator was on hand ­ although an operator was available should you need one.

This ‘open­sourcing’ of EDSAC meant that if a researcher had a brilliant new idea they needed answers to, and it just couldn’t wait, they could fire up the giant calculator and have it pump out what they needed ­ great news, given Cambridge’s propensity for eureka moments.

Inputting your data into EDSAC and then hearing it snap into life as it feverishly, but motionlessly computed the answers to your most challenging questions, would be a thrill even by today’s standards. Your results would then be fed out of the machine on a long strip of paper (five­hole punched tape) ready to be interpreted, and no doubt marvelled at.

So what, it’s just a big calculator?

In essence, yes, EDSAC, and its successor EDSAC 2, were essentially, giant, overachieving calculators. It’s what they allowed their users to do, though, which made them significant within the bigger picture.

Intuition is a valuable human resource, but in order for certain things to work, we often have to make sense of large sets of even larger numbers. It’s something that’s as true in pure mathematics, as it is in chemistry, medicine, biology and physics.

EDSAC does some of the heavy lifting for us, so that we might benefit from the fruits of our hard work.

And how has EDSAC contributed to science?

The EDSAC and EDSAC 2 helped many scientists and researchers move their work forwards more quickly in the machines’ almost 20­year lifespans. EDSAC even helped some Cambridge researchers win Nobel Prizes:

• John Kindred and Max Perutz (Chemistry, 1962) for the discovery of the structure of myoglobin
• Andrew Huxley (Medicine, 1963) for quantitative analysis of excitation and conduction in nerves
• Martin Ryle (Physics, 1974) for the development of aperture synthesis in radio astronomy

Three Nobel Prizes, with each winner acknowledging EDSAC in their acceptance speeches.

Explore further

See EDSAC rebuilt