1. Chapter 2

2. Module 2A Inside the System Unit
Module 2B Data Storage
Module 2C Input and Output
Chapter 2

3. Inside the System Unit Talking about Computer Hardware
The System Unit: Looking Under the hood
How Modern Computers Represent data
The CPU: The Computer’s “Brain”
Microprocessors: Computers on a Chip
Comparing CPUs
Memory: The CPU’s Electronic Scratchpad
Buses: Freeways for Data
Module A

4. Talking about Computer Hardware
Inside the System Unit
Talking about Computer Hardware
Module A
Computer and peripherals

5. The System Unit: Looking Under the Hood The system unit, exposed A
Inside the System Unit
The System Unit:
Looking Under the Hood
Module A
The system unit, exposed

6. How Modern Computers Represent Data
Inside the System Unit
How Modern Computers Represent Data
Digital versus Analog Representation
digital: high and low power signals
analog: continuous variable scale
Numbering systems
every numbering system has a base
Module A

7. Inside the System Unit
Binary Numbers
Module A
A binary number is called a binary digit, or bit. A bit is the smallest unit of information that a computer can work with.

8. Inside the System Unit
Counting
Module A

9. ASCII & EBCDIC Originally used a total of 7 bits
Inside the System Unit
ASCII & EBCDIC
Originally used a total of 7 bits
encodes a total of 128 characters
included letters, numbers & punctuation
Looking for a wider market
IBM and Apple expanded to 8 bits
extended character sets not standardized
Macintosh and PC versions differ
Module A

10. Representing Data Unicode Parity Representing numbers
Inside the System Unit
Representing Data
Unicode
expanded to 16 bits (65,000 characters)
can represent most languages
Parity
extra bit added to coding systems
used to ensure code stored correctly
odd and even parity
Representing numbers
floating point notation
Module A

11. The CPU: Looking Under the Hood System Clock Instruction set
Inside the System Unit
The CPU:
Looking Under the Hood
System Clock
determines speed of the system
Instruction set
list of instructions
Four-step process (machine/processing cycle)
Arithmetic-Logic Unit (ALU)
arithmetic & logical operations
registers are temporary storage
Module A

12. Microprocessors: Computers on a Chip
Inside the System Unit
Microprocessors:
Computers on a Chip
Module A
CPUs in most computers designed for individuals are microprocessors, which are complete CPUs (control unit and ALU) fabricated on a single chip of silicon.

13. CPU Compatibility Compatibility Downwardly Compatible CPU Sockets
Inside the System Unit
CPU Compatibility
Compatibility
a program that can run on a computer
Downwardly Compatible
run programs designed for earlier chips
CPU Sockets
physically holds chip on motherboard
established electrical connections
upgrade socks allow upgrading processors
Module A

14. Comparing CPUs Data Bus Width & Word Size
Inside the System Unit
Comparing CPUs
Data Bus Width & Word Size
number of bits in bus determines word size
16-bit CPU works with 16 bit word size
CISC (complex instruction set computer)
many instructions & special-purpose circuits
RISC (reduced instruction set computer)
bare-bones instruction set
less expensive, more efficient
Module A

15. Comparing CPUs Multitasking Pentium MMX Benchmarks Pentium MMX
Inside the System Unit
Comparing CPUs
Multitasking
processor runs more than one program
Pentium MMX
contains 57 sets of multimedia instructions
more quickly run games & multimedia
Benchmarks
provides basis of comparison
Module A
Pentium MMX

16. CPU’s Electronic Scratchpad
Inside the System Unit
Memory:
CPU’s Electronic Scratchpad
Memory Capacities
kilobyte (K or KB),
megabyte (M or MB),
gigabyte (G or GB)
Random-Access Memory (RAM)
store programs & data being used
each memory location has an address
volatile
Cache Memory
allows maximum speed
Module A

17. Inside the System Unit
Random Access Memory
Module A
data
In RAM, each memory location has an address, just like a post office box.

18. Memory Read-Only Memory (ROM) CMOS non-volatile ROM BIOS, flash BIOS
Inside the System Unit
Memory
Read-Only Memory (ROM)
non-volatile
ROM BIOS, flash BIOS
CMOS
used to store startup configuration options
each memory location has an address
volatile
Module A

19. Buses: Freeways for Data
Inside the System Unit
Buses:
Freeways for Data
Circuits that carry data from one component to another are called busses. The wider the bus, the more quickly the data can flow
Module A

20. Inside the System Unit
Plug and Play
Module A
Microsoft and Intel created the Plug and Play (PnP) standard. This standard requires special chips on the motherboard, compatible hardware that is expressly compatible with the Plug and Play standard, and a system BIOS that supports Plug and Play.

21. Data Storage Storage Concepts: The Basics
Disks and Disk Drives: Putting a Spin on it
Magnetic Tape: Still Useful
Optical Storage Media: Seeing the Light
Storing Data in Files
File Systems in Business: Minding the Store
Module B

22. Storage Concepts: The Basics Memory versus Storage B Data Storage
Module B
Memory versus Storage

23. Storage Devices Sequential Random Access
Data Storage
Sequential
go through fixed sequence to get data
example: tape backup unit
Random Access
can go directly to requested data
faster, more expensive
example: disk drive
Module B

24. Before a disk can be used for storage, it must be formatted
Disks & Disk Drives:
Putting a Spin on it
Data Storage
sectors
Before a disk can be used for storage, it must be formatted
Module B
cluster
tracks

25. Floppy Disks A 3 1/2 inch disk B Data Storage write protection tab
plastic casing
liner
disk
Module
sector hole B
spindle hole
read/write opening
sliding metal shutter
A 3 1/2 inch disk

26. Hard Disks How Hard Disks Work Storage Capacities Physical Performance
Data Storage
How Hard Disks Work
Storage Capacities
Physical Performance
Disk Caches
Hard Disk Interfaces
Hard Disk Maintenance
Backup Procedures
Removable Hard Disks
Module B

27. Data Storage
Hard Disk Interfaces
Module B

28. Data Storage
Removable Hard Disk
Module B
Many new computers come equipped with a Zip drive, a removable hard disk that uses 100MB cartridges. The cartridges cost about $10 each.

29. Magnetic Tape: Still Useful
Data Storage
Quarter-inch cartridge (QIC) tape drives work with cartridges that can hold more than 10MB of data
Module B

30. Optical Storage Media:
Seeing the Light
Data Storage
CD-ROM
CD-R
CD-RW
Module B
CD-ROM disks are prerecorded and cannot be altered. CD-ROM provides an excellent way to distribute large amounts of data at little cost.

31. Optical Storage Media:
Seeing the Light
Data Storage
DVD
DVD-ROM
DVD-RAM
Module B
DVD-ROM drives are expected to replace CD- ROM drives as the standard personal computer equipment in the near future

32. Storing Data in Files Program Files Data Files
Data Storage
Storing Data in Files
files
directory
Program Files
Data Files
Files are always named and can be organized into directories. Just as a filing cabinet has different drawers to organize information, different file directories store related types of files
Module B

33. Types of Data Files Configuration files Text files Graphics files
Data Storage
Configuration files
Text files
Graphics files
Database files
Sound files
Backup files
Module B

34. Microsoft Windows 95, 98, and NT
Naming Files
Data Storage
Microsoft Windows 95, 98, and NT
File names can contain up to 255 characters as well as spaces and some punctuation. The characters \ / : * ? “ < > | cannot be used.
Module B
File names have a 31-character limit. This limitation allows a more descriptive name than with MS-DOS or Windows 3.1, but not as descriptive as Windows 95.
Macintosh

35. Organizing Files into Folders (Directories)
Data Storage
By viewing the directory, you can get information about the files stored on the disk. This information includes the file name, the file size, and the date and time of the file’s creation and last update
Module B

36. Organizing Files into Folders (Directories)
Data Storage
Module B
In Microsoft Windows 95 & 98, the root directory contains several subdirectories, including a Windows directory and a Program Files directory

37. The Data Storage Hierarchy
8 bits = A
Last name field
Module
Four fields = 1 record B
Records combined = file
The data storage hierarchy

38. Types of Files in Data Processing Applications
Data Storage
Transaction file
batch processing
real-time processing
Master file
Report file
Module B

39. Sequential File Organization
Data Storage
The computer processes a sequential file in the order in which the data was encoded in the file
Module B
0452
data
0453
data
0454
Key field

40. Direct (Random) File Organization Location of record on disk
Data Storage
Location of record on disk
Module B
Records in a direct access file are stored according to a position in the file. Every location in primary & secondary storage is assigned a unique address.

41. Indexed Sequential File Organization
Data Storage
With indexed sequential files, records can be accessed either directly (randomly) or sequentially.
Module B

42. Input and Output Understanding Input: Not Just Data Entry
Input Devices: The Computer’s “Senses”
Input Devices in Business & Industry
Biological Feedback Devices
Chemical Detectors
Output Devices: Engaging Our Senses
Printers
Sound Cards & Speakers
Tactile Feedback
Module C

43. Input Devices: The Computer’s “Senses”
Input & Output
Keyboards
numeric keyboard
function keys
toggle keys
Caps Lock key
status indicators
Module C

44. Input Devices: The Computer’s “Senses”
Input & Output
Cursor & Cursor Movements
insertion point
cursor movement keys (arrow keys)
repetitive strain injury (RSI)/cumulative trauma disorder (CTD)
Module C
Ergonomic keyboards help prevent CTD

45. Pointing Devices Mouse operations Clicking click Dragging
Input & Output
Mouse operations
Clicking
Dragging
Double-Clicking
click
Module C
click
click

46. Pointing Devices Trackball Trackpoint Touchpad Touch-Sensitive Screens
Input & Output
Trackball
Trackpoint
Touchpad
Touch-Sensitive Screens
Pen-Based Systems
Module C

47. Additional Input Devices
Input & Output
Soundcards
Microphones & Speech Recognition
Video Capture Cards
Cameras
Scanners
Module C
Handheld scanner

48. Input Devices in Business & Industry
Input & Output
source data automation
image processing systems
magnetic ink character recognition (MICR)
bar code readers
universal product code
mark sense character recognition
optical mark reader (OMR)
Module C

49. Additional Input Devices
Input & Output
Biological feedback devices
Chemical detectors
Module C
Virtual reality programs use helmets to enable users to “move” through a simulated “world.”

50. Output Devices: Engaging Our Senses
Input & Output
Video Adapters
video RAM (VRAM)
video graphics adapter (VGA)
super VGA
refresh rate
flicker
Module C

51. Video Graphics Adapter
Input & Output
Common PC resolutions
640 x 480
800 x 600
1024 x 768
1600 x 1200
Module C

52. Video Graphics Adapter
Input & Output
Common color depth
Color Depth Number of colors
VGA (4 bits) 16
256 Color Mode (8 bits) 256
High Color (16 bits) 65,536
True Color (24 bits) 16,777,216
Module C

53. Laptop color LCD display Desktop computers use a CRT
Monitors
Input & Output
cathode ray tube (CRT)
liquid crystal display (LCD)
Module C
Laptop color LCD display
Desktop computers use a CRT

54. Screen Size Quoted Size and Actual Viewable Area
Input & Output
Quoted Size and Actual Viewable Area
Monitor Size Viewable Area
21 inches 20 inches
17 inches 16 inches
15 inches 14 inches
Module C

55. Additional Monitor Characteristics
Input & Output
dot pitch
interlaced monitors
noninterlaced monitors
multiscan monitors
Module C

56. Impact Printers
Input & Output
Line
letter-quality
dot-matrix
Module C

57. Nonimpact Printers inkjet laser thermal transfer dye sublimation
Input & Output
inkjet
laser
thermal transfer
dye sublimation
snapshot
multifunction
Module C

58. Additional Output Devices
Input & Output
plotters
sound cards and speakers
tactile feedback
Module C
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