1. Technology in Action Chapter 6 Behind the Scenes: A Closer Look at System Hardware

2. Chapter Topics Computer switches Binary number system ASCII / Unicode Creating faster CPUs

3. Data Representation Process of transforming diverse data into a form computers can use for processing Digital devices work with distinct and separate data Analog devices work with continuous data 3

4. Digital vs. Analog Analog Signals Have an Infinite Number of Values Digital Signals Have a Discrete Number of Values In this case, the Analog Wave ranges from 0-1 Note that the Digital Wave is Either 0 or 1 (nothing between) 4

5. Representing Numbers We normally use the decimal numbering system, which uses 10 symbols (0, 1, 2, 3, 4, 5, 6, 7, 8, and 9). Computers use the binary numbering system, which represents all numbers using just two symbols (0 and 1). Everything a computer does is broken down into a series of 0s and 1s, stored with switches 5

6. Switches Representing Data The on/off state of a switch represents one bit of data Bit (binary digit) On = 1 Off = 0 OFF 0 ON 1 01 OR = 1 bit

7. The Binary Number System Describes a number as powers of 2 Also referred to as base 2 numbering system Used to represent every piece of data stored in a computer: all of the numbers, letters, and instructions

8. Chapter 2: Computer Hardware 8

9. The Binary Number System Number systems are organized ways to represent numbers Each number in one system has a corresponding number in another. 128 2x64 64 2x32 32 2x16 16 2x8 8 2x4 4 2x2 2 2x1 1 Binary 01011001 Base 10 0 +64 +0 +16 +8 +0 + 1 = 89 01011001 = 89 Binary Base 10

10. Representing Letters and Symbols American Standard Code for Information Interchange (ASCII) 8 bits = 1 byte = alphanumeric character or symbol 256 different combinations Unicode 16 bits = 2 bytes = one symbol 65,000 different combinations, used for all languages NOT a translator program! 01100001 = a 01000001 = A 00100011 = # 01101101 = m ASCII

11. ASCII Chart

12. ASCII Chapter 2: Computer Hardware 12

13. Microprocessor Performance Factors Serial Processing All Activities are Done on One CPU Pipelining Processes Independent Tasks Simultaneously Overall Job Finishes Earlier Example: If you have 4 sets of laundry to wash, dry, and fold… Do you completely finish one load then start another? 13

14. 14 Serial Processing Pipelining

15. Microprocessor Performance Factors Parallel Processing The tasks are divided among multiple CPUs In previous example, would be like having multiple washer/dryer sets Modern Dual Core Processors actually contain all the circuitry for two separate microprocessors 15