How did calculating machines work before ENIAC?
Well, a person with a paper and pencil can add two 10-digit numbers in about 10 seconds. With a hand calculator, the time is down to 4 seconds. The Harvard Mark 1, an electromechanical computer, could add two 10-digit numbers in 0.3 seconds, about 30 times faster than paper and pencil. The ENIAC was the first electronic digital computer and could add those two 10-digit numbers in 0.0002 seconds — that’s 50,000 times faster than a human, 20,000 times faster than a calculator and 1,500 times faster than the Mark 1. For specialized scientific calculations, it was even faster. So it’s a myth that ENIAC could only add, subtract, multiply and divide. That’s a calculator. ENIAC could do three-dimensional, second-order differential equations. We were calculating [artillery] trajectory tables for the war effort. The trajectory tables were calculated by hundreds of people operating desk calculators — people who were called “computers.” So the machine that does that work was called a computer.
