Not so lean, and definitely not mean—or, computers before they went on a diet

25.02.2016 |

If you have ever been on a diet to lose weight, you are not alone. Computers went on a diet too! Well, not really, but they did shed pounds faster than the winner of The Biggest Loser.

Welcome back to A Brief History of Computers! Today, we are going to learn about electronic computers.

The ENIAC, or the Electronic Numerical Integrator and Computer, is the most famous early electronic computer. It functioned on electrical power, was programmable, and ran faster than any existing computer at that time. So this is as “real” a computer as real computers get to be.

Let’s have a look at the ENIAC, shall we?


Image Source: Public domain image

Classic shot of the ENIAC
Image Source:
Public domain image


The ENIAC occupied a 15,000-square-foot room and weighed a whopping 30,000 kilograms! The room needed a constant supply of cool air to prevent the whole computer from melting down. Just for perspective, the device you are reading this on right now can do more work than the ENIAC and does not heat up to even a fraction of what that machine did.

The ENIAC was built by John Mauchly and J. Presper Eckert, who (along with John von Neumann) designed the EDVAC, or the Electronic Discrete Variable Automatic Computer. The EDVAC weighed roughly 8,000 kilograms and occupied about 500 square feet, well less than the ENIAC.

Soon after ENIAC and EDVAC came computers like UNIVAC I, ILLIAC I, and the strangely named MANIAC I. All of these computers used vacuum tubes or electron tubes, which are sealed glass tubes with near-vacuum conditions that allow electrons to pass freely within them.

Vacuum tubes were all the rage in the 1950s until transistors took over in the 1960s. Transistors were cheaper, slower, and more reliablealmost everything you want in a computerand what’s more, were simpler to build with.

The computers that we have looked at so far were mostly operated by multiple people, largely due to their sheer volume. The ENIAC took days just to be set up to run for a problem, while the EDVAC had 30 people working eight-hour shifts to keep it working.

The LINC, built by Massachusetts Institute of Technology in 1962, was one of the first personal computers; it was meant to be used by only one user. It is the world’s first minicomputer, with its components consisting of a refrigerator-sized electronics cabinet and four stereo-sized modules that could fit on a table. Not so “mini” by today’s standards, but a huge development at that time.

Personal computers soon became increasingly popularsomething we will find out more about tomorrow.

Have a nice day, and see you tomorrow!


Recommended book

“Eniac: The Triumphs and Tragedies of the World’s First Computer” by Scott McCartney


Share with friends