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Computer History . Part Deux. Henry Hollerith. Used Jacquard’s hole punched cards to operate a machine using electrical impulses 1890 - machine used to compute US Census Later founded IBM. Analogs. Most machines in 1900s Direct relationship between a task & outcome of task
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Computer History Part Deux
Henry Hollerith • Used Jacquard’s hole punched cards to operate a machine using electrical impulses • 1890 - machine used to compute US Census • Later founded IBM
Analogs • Most machines in 1900s • Direct relationship between a task & outcome of task • 1930’s even computers were • Used gears & wheels to complete calculations
Binary • Developed because telephones were analog • Military wanted something more secure • Digital • By 1962, phone companies used digital signals for civilians • Small jolt of high or low voltage electricity • Resulted in 1 or 0 • Translates back into sound on receiving end
First Computer • Took up an ENTIRE room • Digital • Used vacuum tubes
Vacuum Tubes • Glass tubes • Converted electricity to signals • Fragile, lots of electricity, gave off a lot of heat • Each processed one bit of information at a time • Thousands needed to make a computer work
Transistor • Bell Laboratories invented • By 1947, did everything a vacuum tube could do • 1/200th the size of vacuum tube • More reliable, less electricity, almost no heat • Computers decreased in size
More Transistors • Now even smaller • Used in almost all electronic devices • Watches, clocks, ovens, microwaves, televisions, radios
Integrated Circuit • Also known as Silicon Chip • Designed in 1958 by Jack Kilby • Contains thousands of transistors that are etched into a silicon chip that is smaller than a dime • Thousands & thousands of transistors to handle the circuits of one integrated circuit
Microprocessor • 1971, Marcia Hoff developed • Made of very small semiconductor chips • Tiny integrated circuit made it possible to put many complex circuits & memory storage on a very small chip.
Binary Language • Universal language for computers • Made up of only 1s and 0s • High & Low voltage signals • Make it possible to communicate with each other
ASCII • American Standard Code of Information Interchange • Example of binary language • Eight signals been designated as letters • A on the screen is 01000001 • Everything is 0s & 1s • Hundreds or thousands to make a picture