1. CHAPTER 2
Computer Hardware

2. Chapter Contents
Section A: Data Representation and Digital Electronics
Section B: Microprocessors and Memory
Section C: Storage Devices
Section D: Input and Output Devices
Chapter 2: Computer Hardware

3. Section A: Data Representation and Digital Electronics
Quantifying Bits and Bytes
Digital Electronics
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4. 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
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5. Data Representation Numeric data Character data
Binary number system
Character data
ASCII, Extended ASCII, and Unicode
Digitizing is the process of converting analog data into digital format
File headers contain information about the code used to represent file data
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6. Data Representation
Chapter 2: Computer Hardware

7. Quantifying Bits and Bytes
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8. Digital Electronics
Bits take the form of electrical pulses that can travel over circuits
System unit
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9. Digital Electronics
An integrated circuit (computer chip) is a super-thin slice of semiconducting material packed with microscopic circuit elements
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10. Digital Electronics
The computer’s main circuit board is called the system board, or motherboard
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11. Section B: Microprocessors and Memory
Microprocessor Basics
Microprocessor Performance Factors
Today’s Microprocessors
Random Access Memory
Read-only Memory
CMOS Memory
Buying a Computer
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12. Microprocessor Basics
A microprocessor is an integrated circuit designed to process instructions
ALU
Registers
Control unit
Instruction set
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13. Microprocessor Performance Factors
Microprocessor clock
Megahertz
Gigahertz
Word size
Cache
Level 1 cache (L1)
Level 2 cache (L2)
CISC vs. RISC technology
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14. Microprocessor Performance Factors
Serial processing
Pipelining
Parallel processing
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15. Microprocessor Performance Factors
Dual core processors contain the circuitry for two microprocessors
Benchmark tests gauge the overall speed of a microprocessor
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16. Today’s Microprocessors
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17. Random Access Memory
Random Access Memory is a temporary holding area for data, application program instructions, and the operating system
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18. Random Access Memory
Microscopic capacitors hold the bits that represent data
Most RAM is volatile
Requires electrical power to hold data
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19. Random Access Memory
RAM capacity is expressed in megabytes or gigabytes
Personal computers typically feature between 128 MB and 2 GB of RAM
An area of the hard disk, called virtual memory, can be used if an application runs out of allocated RAM
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20. Random Access Memory
RAM speed is often expressed in nanoseconds or megahertz
SDRAM is fast and relatively inexpensive
DDR
RDRAM is more expensive, and usually found in high-performance workstations
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21. Read-Only Memory
ROM is a type of memory circuitry that holds the computer’s startup routine
Permanent and non-volatile
The ROM BIOS tells the computer how to access to hard disk, find the operating system, and load it into RAM
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22. CMOS Memory Stores basic system information
More permanent than RAM, and less permanent than ROM
Requires very little power to hold data
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23. Buying a Computer Assess your budge
Think about how you plan to use your computer
Look at ads and visit online computer stores
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24. Section C: Storage Devices
Storage Basics
Floppy Disk Technology
Hard Disk Technology
Tape Storage
CD and DVD Technology
Solid State Storage
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25. Storage Basics A storage medium contains data
A storage device records and retrieves data from a storage medium
Data gets copied from a storage device into RAM, where it waits to be processed
Processed data is held temporarily in RAM before it is copied to a storage medium
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26. Storage Basics
Magnetic storage stores data by magnetizing microscopic particles on the disk or tape surface
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27. Storage Basics
Optical storage stores data as microscopic light and dark spots on the disk surface
CD and DVD storage technologies
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28. Storage Basics
Solid state storage technology stores data in a non-volatile, erasable, low-power chip
Some solid state storage requires a card reader to transfer data to or from a computer
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29. Storage Basics Most desktop computers have several drive bays, some
accessible from outside the
case, and others—designed for
hard disk drives—without any
external access. Empty drive
bays are typically hidden from
view with a face plate.
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30. Storage Basics Versatility Durability Speed Capacity Access time
Random vs. sequential access
Data transfer rate
Capacity
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31. Floppy Disk Technology
Used for standard HD DS disks and Zip disks
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32. Hard Disk Technology Hard disk platters are sealed
inside the drive case or cartridge
to prevent dust and other
contaminants from interfering
with the read-write heads.
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33. Hard Disk Technology
A controller positions the disk and read-write heads to locate data
SATA
Ultra ATA
EIDE
SCSI
Not as durable as many other storage technologies
Head crash
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34. Tape Storage
A tape backup stores a copy of the data on a hard disk on a magnetic tape
A tape is a sequential storage medium
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35. CD and DVD Technology
A CD can hold up to 80 minutes of music or 700 MB of data
A DVD can hold about 4.7 GB of data
A double-layer DVD can store 8.5 GB of data
HD-DVDs can store 15 GB
Blu-ray DVDs can store 25 GB
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36. CD and DVD Technology CD-DA DVD-Video CD-ROM DVD-ROM CD-R
DVD+R or DVD-R
CD-RW
DVD+RW or DVD-RW
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37. CD and DVD Technology
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38. Solid State Storage USB flash drive CompactFlash (CF) cards
MultiMedia cards (MMC)
SecureDigital (SD)
SmartMedia
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39. Section D: Input and Output Devices
Basic Input Devices
Display Devices
Printers
Installing Peripheral Devices
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40. Basic Input Devices Keyboard Pointing device Pointing stick Trackpad
Trackball
Joystick
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41. Display Devices A CRT display device uses a bulky glass tube
An LCD manipulates light within a layer of liquid crystal cells
Plasma screen technology illuminates lights arranged in a panel-like screen
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42. Display Devices Viewable image size Dot pitch Viewing angle width
Refresh rate
Color depth
Resolution
VGA, SVGA, XGA, SXGA, and UXGA
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43. Display Devices
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44. Display Devices
Graphics circuitry generates the signals for displaying an image on the screen
Integrated graphics
Graphics card
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45. Printers
An ink-jet printer has a nozzle-like print head that sprays ink onto paper
A laser printer works like a photocopier
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46. Printers Laser printers are a popular technology when high-volume
output or good-quality printouts
are required.
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47. Printers
Dot matrix printers produce characters and graphics by using a grid of fine wires
The wires strike a ribbon and the paper
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48. Printers
Other printer technologies include solid ink printers, thermal transfer printers, and dye sublimation printers
Printer features
Resolution
Print speed
Duty cycle
Operating costs
Duplex capability
Memory
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49. Installing Peripheral Devices
The data bus moves data within the computer
Expansion cards are small circuit boards that give the computer additional capabilities
Expansion slot
ISA
PCI
AGP
PCMCIA
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50. Installing Peripheral Devices
An expansion card simply slides
into an expansion slot and is secured with a small screw. Before you open the case, make sure you unplug the computer and ground
yourself—that’s technical jargon
for releasing static electricity by
using a special grounding wristband
or by touching both hands to a metal object.
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51. Installing Peripheral Devices
An expansion port passes data in and out of a computer or peripheral device
Peripheral device may include the Plug and Play feature, or require a device driver
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52. Installing Peripheral Devices
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53. CHAPTER 2 COMPLETE
Computer Hardware