Eniac Electronic Numerical Integrator and Calculator

The ENIAC (Electronic Numerical Integrator and Computer) was the first general-purpose electronic computer. Developed during World War II, it revolutionized computing by introducing electronic components instead of mechanical or electromechanical ones. This guide explores ENIAC's history, architecture, and lasting impact on computer science.

History of ENIAC

ENIAC was developed at the University of Pennsylvania's Moore School of Engineering between 1943 and 1945 under the leadership of John Presper Eckert and John William Mauchly. The project was funded by the U.S. Army for calculating artillery firing tables during World War II.

The original name was Electronic Numerical Integrator and Computer, but it was later shortened to Electronic Numerical Integrator and Calculator. ENIAC was completed in 1945 and officially unveiled on February 14, 1946.

ENIAC was about 1,000 times faster than the previous generation of electromechanical computers, demonstrating the power of electronic computing.

Architecture and Components

ENIAC's architecture was groundbreaking for its time. It consisted of:

17,468 vacuum tubes
7,200 crystal diodes
1,500 relays
70,000 resistors
10,000 capacitors
1,400 kilobytes of mercury delay line memory
1,000 manual switches

The computer was programmed by physically rewiring its connections and setting switches, making it a pluggable computer. It could perform about 5,000 additions or 357 multiplications per second.

Performance: ENIAC could execute approximately 5,000 additions per second or 357 multiplications per second.

Impact on Computing

ENIAC's development marked several milestones in computer history:

First general-purpose electronic computer
Introduced the concept of stored-program computers (though ENIAC itself didn't use stored programs)
Demonstrated the feasibility of large-scale electronic computing
Paved the way for subsequent computer generations

ENIAC's success led to the development of the EDVAC (Electronic Discrete Variable Computer) and other early computers. Its architecture influenced the design of modern computers, particularly in the use of electronic components.

Technical Specifications

Specification	Value
Word size	10 decimal digits
Memory	20 registers (200 decimal digits)
Clock speed	100 kHz
Power consumption	150 kW
Physical size	30 tons, 1,670 sq ft

Despite its massive size and power consumption, ENIAC was a revolutionary achievement in computing technology.

Frequently Asked Questions

What does ENIAC stand for?: ENIAC stands for Electronic Numerical Integrator and Computer, though it was later referred to as Electronic Numerical Integrator and Calculator.
When was ENIAC developed?: ENIAC was developed between 1943 and 1945 and officially unveiled on February 14, 1946.
What was ENIAC's primary purpose?: ENIAC was primarily used to calculate artillery firing tables for the U.S. Army during World War II.
How did ENIAC differ from previous computers?: ENIAC was the first general-purpose electronic computer, using vacuum tubes instead of mechanical or electromechanical components.
What was ENIAC's impact on computing?: ENIAC demonstrated the power of electronic computing and influenced the development of subsequent computer generations.