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Unformatted text preview: Computer science is a discipline that involves the understanding and design of computers and computational processes. Hardware : Physical Devices: processor, memory,keyboard, monitor, mouse, etc . Software: Executable Programs: word processers ,spread sheet, internet browser, etc. Control Unit :fetches an instruction from primary storage decodes it to decide which instruction it is instructs the ALU to perform a calculation . Arithmetic-Logic Unit (ALU) performs arithmetic calculations and logical calculations such as comparison (separate integer and floating-point units). Moore’s “Law”: Gordon Moore is one of the founders ofthe chip maker Intel. In 1965, he has observed the growth rate of the number of transistors in a circuit.Made a famous prediction. How fast? Today’s processors run at GHz speeds.That is 1 billion “operations” a second or 1 operation each nanosecond. Speed pushing up against physics: The “clock” is like a drummer in the band.The faster it beats, the faster the operations.At 1 Ghz in 1 clock tick electricity travels 1 ft.At 2GHz, 6 inches,At 4GHz, 3 inches It becomes very difficult to get electricity across the board fast enough! Primary Storage: stores instructions and data for current program(s) other names: primary or main memory, RAM (Random Access Memory) memory is “dynamic”...
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- Fall '07
- Computer Science, Orders of magnitude, Units of information, Alan Turing