1. Chapter 4 Inside the Computer
Computers: Information Technology in Perspective, 11e Larry Long and Nancy Long
Chapter 4
Inside the Computer
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Objectives
Once you have read and studied this chapter, you will have learned:
How data are stored and represented in a computer system.
The function of and relationships between the internal components of a personal computer, including the motherboard, processor, RAM and other memories, ports, buses, expansion boards, and PC cards.
How to distinguish processors by their word size, speed, and memory capacity.
Several approaches to processor design.
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3. Why this chapter is important to you!
Learning about computers can help you make smart purchasing decisions when it comes time to buy the next computer
To get what you need and want out of a computer you have to know what you are doing
Details about computer components is a must for making informed decisions about purchases
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Going Digital
Analog
A computer is:
A CD player
Video player
Family photo album
And more…
Digitizing means converting analog signals to 1s and 0s
Digital
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Binary Digits: 1 and 0
Binary digits represent letters, numbers, colors, shapes, and more
The on state is 1
The off state is 0
RAM
Presence or absence of an electrical charge
DISK
Magnetic arrangement CD
Permanent microscopic pits
Fiber Optic
Pulses of light
Only 2
states possible On
Off
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6. Encoding Systems: Bits and Bytes
Most popular encoding system for PCs
Characters equate to a series of 1s and 0s
Letter B=
7-Bit ASCII can represent up to 128 characters
The PC byte is 8 bits and can represent up to 256 configurations
The first 128 ANSI codes represent needs of the Windows applications
The new Unicode is a 16-bit code allowing for 65,526 characters
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Hexadecimal
Hexadecimal or base-16 is used as a shorthand to display binary contents of RAM or disk storage
A single hexadecimal digit represents four binary digits
Two hexadecimal digits can be used to represent an eight-bit byte
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The PC System Unit
The PC system unit
Houses all electronic components
Usually a metal and plastic upright box called tower or a notebook’s shell
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9. The Motherboard: The Central Nervous System
The motherboard is a single circuit board and houses:
Processor
Chipset
Memory Chips
Expansion Slots
Motherboard provides a path (bus) for the processor to communicate with other components
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10. The Processor: Computer on a Chip
It is a self-contained integrated circuit
First PC used an Intel 8088 chip
What came after:
Intel 286, 386, and 486
Pentium, Pentium Pro, Pentium II, III, and IV
Pentium Celeron or Itamium
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Inside the Processor
The processor or CPU, as it is also called:
Reads and interprets programs
Directs operations
Controls the flow of programs and data
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12. The Arithmetic and Logic Unit
Performs computations:
Addition
Subtraction
Multiplication
Division
Results of computations are placed in the accumulator
Examples:
Payroll deductions
Bank statement balances
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13. RAM: Digital Warehouse
Volatile & temporary
Programs/data are loaded into RAM storage
High-speed holding area
Ram Types:
SDRAM
DDR SDRAM
RDRAM
Chips:
SIMM
DIMM
RIMM
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14. Cache and Other High-Speed Memories
Cache memory
High-speed holding area that would be retrieved more frequently
Level 1
Built into the processor
Level 2
Ultra-fast memory
ROM
Read only
Cannot be altered
Flash
Type of PROM
Can be altered
Survives electrical interruptions
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15. What Happens Inside: Unraveling the Mystery
Instruction
Time
Execution
Fetch Instruction
Execute Instruction
Place Result in Memory
Decode Instruction
BASIC programming
Intuitive instructions
Machine language
Translated
Instruction cycle
Executing instructions
Pipelining
Begin next execution before first is completed
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16. Putting It All Together
Expansion Slots
Expands the PC
Such as:
Extra ports
Modem
Video
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17. Putting It All Together
Bus Support Type:
PCI
Links directly to common bus
Universal Serial Bus
Permits up to 127 devices
1394
Permits 63 external
30 times faster than USB
SCSI
Permits up to 15 devices
AGP
Direct link for graphics adapter
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18. Putting It All Together
Ports
Serial
Parallel
SCSI
USB
1394
Keyboard/Mouse
IrDA
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19. PC Growth: Adding Capabilities
Expansion Boards
Graphics Adapter
Sound
Data/Voice/Fax
USB hub
Network Interface card
Video Capture
PCMCIA
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20. Describing the Processor and Its Performance: Word Size
Describes the number of bits that are handled
Most computers have 64-bit internal processing, but only a 32-bit bus path
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21. Describing the Processor and Its Performance: Core Speed
Speed of a computer
PCs
Measured in GHz
Billions of clock cycles per second
Workstations & servers
MIPS
Millions of instructions per second
Supercomputers
FLOPS
Trillions of instructions per second
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22. Describing the Processor and Its Performance: Bus Speed
Measured in cycles per second
Operates at MHz speed
Usually around 250 to 600 MHz for modern PCs
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23. Describing the Processor and Its Performance: Memory Capacity
Kilobits (Kb)
1024 bytes
Megabytes (MB)
1,048,576 bytes
Gigabytes (GB)
About 1 billion bytes
Terabytes (TB)
About 1 trillion bytes
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24. Describing the Differences
Parallel Processing
Multiple processors
Neural Networks
Processor that mimics the human brain
Grid Computing
Shared processing
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Summary
Going digital
Analog
Digital
The PC system unit
System Unit
Describing the processor and its performance
MHz
GHz
MIPS
FLOPS
Processor design
Parallel
Neural
Grid
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