Simple Computers
• By definition, a computer is any device capable of performing mathematical equations or calculations. Therefore, many simple devices such as an abacus (which dates back to at least 300 BCE) or a slide rule (first made in England in the 1630s) are the forerunners of today's modern computers.
The Calculating Clock
• The first machine that worked like a computer was a gear-powered German device dubbed the Calculating Clock. It was first created by Wilhelm Schickard in 1623, and it operated by pulling or pushing rods set inside a glass case. A similar device known as a Pascaline became popular in the 1640s. These two devices were the forerunners of a steam-powered "difference engine" that was a pet project of Charles Babbage in the 1820s.
Harvard Mark-1
• In 1944, the Harvard Mark-1 computer is completed. This computer is closer to a modern computer, but is really just a large calculator driven by a camshaft with no stored programs. This massive computer filled a large room and was a joint effort between Harvard University and IBM.
ENIAC
• Another important computer dating from the 1940s is the ENIAC, which was built between 1943 and 1945. ENIA (Electronic Numerical Integrator and Calculator) was a project of the University of Pennsylvania, and spanned many rooms and used nearly 20,000 vacuum tubes.
The Dawn of the Microprocessor
• A microprocessor is a chip that basically contains an entire computer (or at least a 1940's era computer) using a integrated circuit. The first microprocessor was made by Intel in 1971. With the advent of this technology, the home computer become a possibility.
The First PC
• The first personal computer for home use was the Altair 8800, which