| A | B |
|---|
| abacus | first recorded adding machine |
| Blaise Pascal | first mechanical calculation machine |
| Leibniz | "stepped reckoner" all four basic arithmetic functions often inaccurately |
| Comar | "arithometer" all four basic arithmetic functions accurately |
| punched card | popular method for entering data through the 1980's |
| Herman Hollerith | Known as the father of information processing for his successful use of punched cards |
| Charles Babbage | Invented the steam powered "difference engine" and the "analytical engine a mechanical adding machine. |
| Conrad Zuse | Built the first progammable computer known as the Z3 |
| Astanasoff & Berry | Completed the first all-electronic computer called the ABC |
| Vaccuum tubes | The first major electrical part of a computer |
| Howard Aiken | In 1944 built the first electromechanical calculator. It was called the "Mark 1" and could achieve 3 calculations each second |
| Eckert and Mauchly | In 1945 developed the first operational electronic digital computer, called ENIAC. It was over 1000 times faster than Mark 1 |
| First generation computers | The first true computers, they were made between 1951 & 1959, and used electricity, vacuum tubes, and magnetic drums and tape for memory |
| Second generation computers | Built between 1959 and 1963 these computers used a new invention, the transistor. They were easier to program, used high-level languages and had magnetic cores and disks for memory |
| Third generation computers | These computers relied on another new technology, the integrated circuit. These integrated circuits were faster, offered improved memory and reduces the price of computers. They were built between 193 & 1974. |
| Fourth generation computers | They are based on the microprocessor, which was first invented in 1974 by Dr. Ted Hoff at Intel Corporation. The microprocessor is still the single greatest innovation of the computer world |
