12 Things You Didn’t Know About ENIAC

Posted 02/14/2011 at 11:48am | by George Jones

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Feb. 14 is the 65th anniversary of the first real supercomputer. Is there any better way to celebrate Valentine’s Day than with a dozen ENIAC factoids?

ENIAC. These days, the name conjures up one ginormous lonely computer, a relic of other times. But back in the day – February 14, 1946 to be specific – the US Army thought pretty highly of its brand new Electronic Numerical Integrator and Computer, the world’s first general-purpose electronic computer.

Created with the original intent of calculating artillery firing tables for the Army’s Ballistic Research Laboratory, ENIAC’s completion was announced on Valentine’s Day, and then formally introduced to the American public the very next day on February 15.

This year, our Valentine’s Day ode to computing takes the form of one dozen lovely factoids about ENIAC. Enjoy!

1. Upon being completed, ENIAC contained 17,458 vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors, and 5 million hand-soldered joints. The total power consumption was a whopping 160 kilowatts. In one second, the ENIAC could perform 5,000 additions, 357 multiplications, or 38 divisions.

2. The total cost of ENIAC, which weighed over 25 tons and took up approximately 680 square feet, was $500,000. That’s about $6 million today, adjusted for inflation.

3. ENIAC was conceived and designed by John Mauchly and J. Presper Eckert. It took Mauchly and Eckert one year to design and 18 months to build it. While the original intention behind ENIAC was to calculate artillery firing tables for the Army, the war was over by the time it was put into service. Instead, the military used the computer for calculations in designing the hydrogen bomb, weather prediction, and a multitude of studies including cosmic-rays, thermal ignition, random numbers, and wind-tunnel design.

4. Programming the ENIAC consisted of operating a massive series of plugs and switches. It took several days to input and run programs on the ENIAC. This said, ENIAC’s power (at the time) was still marvelous; It could perform the functions that one man would spend 20 hours on in around 15 minutes.

5. The original programmers of ENIAC computer were women. The most famous of the group was Jean Jennings Bartik (originally Betty Jennings). The other five women were Kay McNulty, Betty Snyder, Marlyn Wescoff, Fran Bilas, and Ruth Lichterman. All six have been inducted into the Women in Technology International Hall of Fame. When the U.S. Army introduced the ENIAC to the public, it introduced the inventors (Dr. John Mauchly and J. Presper Eckert), but it never introduced the female programmers.

6. Jean Bartik went on to become an editor for Auerback Publishers, and eventually worked for Data Decisions, which was funded by Ziff-Davis Publishing. She has a museum in her name at Northwest Missouri State university in Maryville, Missouri.

7. While ENIAC was capable of performing parallel calculations, thanks to the ability to connect the super-computer’s twenty different accumulators together.

8. Unfortunately, a freeze on design in 1943 meant that ENIAC was not initially capable of storing programs in any type of memory.

9. An extensive 1948 modification allowed the ENIAC to store programs in a rudimentary form of memory. A single-address architecture allowed the three digits of one accumulator to be used as a program counter, while another accumulator was used as the address pointer for reading data. A third accumulator was used as the main accumulator, and the rest of the accumulators were used as data storage. This modification reduced the speed of ENIAC considerably, but also greatly reduced the amount of time it took to program the system.

10. ENIAC was the world’s first general-purpose electronic computer, but its reliance on vacuum tubes initially proved troublesome. In its early years, several tubes would burn out every day, leaving the computer inoperable for about half the time it was on. One of the reasons ENIAC was never shut off was because the main cause of vacuum tube failures was turning it on – the warm-up and cool-down periods created the most thermal stress.

11. ENIAC ran continuously from July 29, 1947 to October 2, 1955.It was replaced by the Electronic Discrete Variable Automatic Computer (EDVAC), a binary stored program system with 5.5KB of internal memory that begun operations in 1951.

12. In 1973, the landmark federal court case Honeywell vs. Sperry Rand voided US patent 3,120,606 for the ENIAC and placed the invention of the electronic digital computer in the public domain. This same ruling also provided legal recognition for <a href=http://en.wikipedia.org/wiki/John_Atanasoff>John Atanasoff</a> as the inventor of the first electronic digital computer. (The Atanasoff-Berry Computer was a non-programmable code-breaking machine that was first put into service in 1942.)