| A | B |
|---|
| Pascaline | Set of gears, similar to clock Only performed addition |
| Stepped Reckoner | Gottfried Leibniz Cylindrical wheel with movable carriage Add, subtract, multiply, divide, square roots Jammed/malfunctioned |
| Difference Machine | Charles Babbage Produce table of numbers used by ships’ navigators. Never built |
| Analytical Machine | Perform variety of calculations by following a set of instructions (or program) on punched cards Never built Used as a model for modern computer |
| Ada Byron | Sponsor of Analytical Machine One of first people to realize its power and significance Often called the first programmer because she wrote a program based on the design of the Analytical Machine. |
| Hollerith’s Tabulating Machine | Herman Hollerith – used electricity For US Census Holes representing information to be tabulated were punched in cards |
| Mark I | IBM & Harvard Mechanical telephone replay switches to store information and accepted data on punch cards. Highly sophisticated calculator - unreliable |
| Atanasoff-Berry Computer | Built b/w 1939-1942 Used binary number system Vacuum tubes Stored info by electronically burning holes in sheets of paper. |
| ENIAC | Electronic Numerical Integration and Calculator 1943, 30 tons, 1500 sq ft., 17,000+ vacuum tubes Secret military project during WWII to calculate trajectory of artillery shells. Solve a problem in 20 min that would have take a team of mathematicians three days to solve. |
| Computer | An electronic machine that accepts data, processes it according to instructions, and provides the results as new data |
| Mauchly & Eckert built 3rd computer | 1st computer language – C-10 (developed by Betty Holberton) Holberton also developed first keyboard and numeric keypad First UNIVAC sold to US Census Bureau in 1951 |
| 1947, Bell Lab | Invented the transistor Replaced many vacuum tubes Less expensive, increased calculating speeds |
| Model 650 | IBM introduced first medium-sized computer (Model 650) |
| Second Generation Computers | Magnetic tape and high speed reel-to-reel tape machines replaced punched cards. Magnetic tape gave computers ability to read (access) and write (store) data quickly and reliably |
| Third Generation Computers | Integrated circuits (ICs) – replaced transistors Kilby and Noyce – working independently developed the IC (chip). ICs Silicon wafers with intricate circuits etched in their surfaces and then coated with a metallic oxide that fills in the etched circuit patterns. IBM System 360 (1964) One of first computers to use IC |
| Mainframes | A large computer that is usually used for multi-user applications. IBM System 360 one of first mainframes. Used terminals to communicate with mainframe. |
| Fourth Generation Computer | Microprocessor (1970) Hoff at Intel Corp, invented microprocessor. Entire CPU on a chip. Makes possible to build the microcomputer (or PC). Altair – one of first PCs 1975. Wozniak and Jobs designed and build first Apple Computer in 1976. IBM introduced IBM-PC in 1981. |
