Techno News

The ENIAC (electronic numerical integrator and computer) was the first usable electronic
computer. It was designed by J. Presper Eckert and John Mauchly at the University of
Pennsylvania and was completed in 1946—two years before transistors were invented. The
computer was housed in a large room and consisted of many cabinets containing about
18,000 vacuum tubes (see Figure 6). Vacuum tubes burned out at the rate of several tubes per
day. An attendant with a shopping cart full of tubes constantly made the rounds and replaced
defective ones. The computer was programmed by connecting wires on panels. Each wiring
configuration would set up the computer for a particular problem. To have the computer
work on a different problem, the wires had to be replugged.


Work on the ENIAC was supported by the U.S. Navy, which was interested in computations
of ballistic tables that would give the trajectory of a projectile, depending on the wind
resistance, initial velocity, and atmospheric conditions. To compute the trajectories, one must
find the numerical solutions of certain differential equations; hence the name “numerical
integrator”. Before machines like ENIAC were developed, humans did this kind of work,
and until the 1950s the word “computer” referred to these people. The ENIAC was later
used for peaceful purposes such as the tabulation of U.S. Census data.