ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Monday, February 12, 1996 TAG: 9602130090
SECTION: NATIONAL/INTERNATIONAL PAGE: A1 EDITION: METRO
DATELINE: PHILADELPHIA
SOURCE: ASSOCIATED PRESS
note: below
It had no monitor, could remember only 20 numbers at a time, and filled a room with 50 tons of electricity-sucking gear.
But it could crunch numbers with what seemed like blinding speed.
Fifty years ago this week, the Electronic Numerical Integrator and Computer was demonstrated to the world for the first time at the University of Pennsylvania.
ENIAC counted to 5,000 in one-fifth of a second, shocking the world out of the mechanical age and onto the first step of the world of lightning-quick digital processing.
ENIAC's collection of 8-foot-high gray cabinets made up the first general-purpose, large-scale, electronic computer. Until then, ``computers'' were people using mechanical calculators who needed 12 hours to do what ENIAC did in half a minute. Other electronic machines had been narrower in purpose.
``Without it, we wouldn't have the space program, we wouldn't have modern airplanes,'' said Michael Williams, editor in chief of Annals of the History of Computing. ``Pilots would still be trying to fly by looking outside the window occasionally.''
ENIAC, most of which is on display at the Smithsonian, long ago outgrew its usefulness as a number cruncher - a $40 calculator has more computing power.
But it has not lost its relevance.
The university planned an entire year of events to honor ENIAC's birthday, including turning on part of the machine. Vice President Al Gore will throw a switch Wednesday, the day of the anniversary, and ENIAC will count from 46 to 96.
The Postal Service will unveil a stamp commemorating ``The Birth of Computing.''
ENIAC's original assemblage of wires, vacuum tubes, resistors and switches was constructed in about a year and a half at the university's Moore School of Electrical Engineering.
When it was fully operational, ENIAC filled a 30-by-50-foot room. Every second it was on, it used enough electricity - 174 kilowatts - to power a typical Philadelphia home for 1 1/2 weeks.
Costing more than $486,000, ENIAC might never been attempted were it not for World War II.
``A lot of people said we were dreaming,'' said Herman Goldstine, who served as liaison between the Army and the ENIAC team. ``The electronics people said there were too many vacuum tubes and it would never run. The mathematics people said there were no problems complex enough that computers were needed.''
The Army provided both the complex problems and the money.
John Mauchly, one of two masterminds behind ENIAC, knew the Army was having a terrible time working out the complicated firing tables needed to help gun crews aim the new artillery being used against German forces.
Each firing table had to list numbers for hundreds of potential trajectories. Calculating a single trajectory could take 40 hours using a mechanical desktop calculator, and 30 minutes using a sophisticated machine called a differential analyzer.
Mauchly, then 32, bravely told Army officials his machine could do the job in a matter of minutes.
ENIAC was completed just as the war was ending, too late for the those artillery tables.
However, it fulfilled another military purpose. During test runs in 1945 it did millions of calculations on thermonuclear chain reactions, predicting the destruction that could be caused by the hydrogen bomb.
Two critical concepts for future computing evolved out of ENIAC. One was the idea of a ``stored program'' and the other a programming tool known as the ``if statement.''
Today's personal computers can store numerous programs. But for ENIAC, engineers had to drag around 40-pound trays of wires and vacuum tubes to change settings and perform simple tasks. They quickly realized the need for increased memory.
The ``if statement'' was just as important. It permitted the computer to choose between different outcomes based on different inputs.
``Without an `if statement,' you've basically got a calculator,'' said Mitch Marcus, chairman of the Computer Science Department at Penn. ``With an `if statement,' you can essentially program a computer to do anything. Without it, a computer is very, very limited. It's the crucial thing which jumps you from calculators to computers.''
In the early 1970s, a legal dispute broke out over whether ENIAC was in fact the first electronic computer.
A court decided that the Atanasoff-Berry Computer built at Iowa State University was first, nullifying the 100-plus patents filed by Mauchly and partner J. Presper Eckert.
However, Penn officials point out that the ABC computer was designed to do one thing - solve parts of linear equations - as opposed to the general design of ENIAC.
Another electronic computer had been built in England, but it, too, was single-purpose: cracking Germany's Enigma military codes.
In any event, many scientists were rushing toward electronic computation, said Gwen Bell, founding president of the Computer Museum in Boston.
``It's one of those inventions that was going to happen and was happening around the world at the same time,'' she said.
LENGTH: Long : 101 lines ILLUSTRATION: PHOTO: AP Jan Van der Spiegel holds a microprocessor (theby CNBblack dot on the square) in front of one-tenth of the original
computer, which weighed 50 tons. color