1. Computer Hardware
Unit B

2. Objectives Introduce Storage Technology Compare Storage Technologies
Compare Storage Media and Devices
Explore Floppy Disk Technology
Explore CD/DVD Technology

3. Objectives Understand Expansion Slots, Cards, Ports, and Cables
Compare Display Devices
Compare Printers
Examine Keyboards
Explore Peripheral Devices

4. Storage Technology Storage = Medium + Device
Storage Medium: disk, CD, DVD
Storage Device: mechanical; disk drives, CD drives
Lab: working with binary numbers
Storage = Medium + Device

5. Storage Process Data copied from storage device to RAM
Processed in RAM
Volatile (temporary) high speed storage
Data copied back to storage medium (permanent)
Storing data is writing/saving file
Retrieving data is reading/loading/opening file

6. Storage Comparison
Magnetic
Optical
vs.

7. Magnetic Storage Magnetizes microscopic particles on medium surface
Permanent, but modifiable
Hard disk, floppy disk, zip disk and tape
Read-write head
Not very durable

8. Optical Storage
Stores data as microscopic light and dark spots on disk surface
Pits and lands
Uses laser lights
More durable

9. Comparing Storage Devices
Versatility
Durability
Speed
Access time
Milliseconds
Random vs. sequential access
Data transfer rate
Capacity
KB, MB, GB, TB
Disk density

10. Comparing Storage Devices
Device Cost
Media Cost
Capacity
Floppy disk
$40-99
$.30
1.44 MB
Zip disk
$139 (avg)
$11.00
250 MB
Fixed disk
$150 (avg)
- NA -
40 GB (avg)
CD-R $
$.50
680 MB
CD-RW
$1.50
Writable DVD
$500 (avg)
$25.00
5.2 GB
Tape
$199 (avg)
$50.00
30 GB (avg)

11. Adding Storage Devices
Upgrading
System Unit contains drive bays
CD video: drive bays

12. Floppy Disks are Portable
Zip disks (Iomega): 100 and 250 MB
SuperDisks (Imation): 120 MB
3½” disk: 1.44 MB
Info web: floppy disk drives

13. Hard Disks (Fixed Disks)
One or more platters with read/write heads
Capacity averages 40 GB
Very fast access times (rpm)
Platters divided into tracks, sectors, cylinder
Controller (circuit board)
Ultra AT
EIDE
SCSI
Head Crash
CD video: how a hard disk works

14. RAID Redundant Array of Independent Disks Combines two or more drives
Faster access and protects data from loss
Mainframes and servers

15. CD Technology CD-ROM: Compact Disk Read-Only Memory
Manufactured; cannot change; 680 MB
CD-R: Compact Disk Recordable
You record; cannot be erased or modified
CD-RW: Compact Disk Rewritable
You record; can erase and modify
Archiving Data
Info web: CD and DVD

16. DVD Technology Digital Video Disk Originally alternative to VCR 4.7 GB
Manufactured
Can play CD-ROM and most CD-Rs and CD-RWs

17. Busses Data Bus: circuits on which data travels within the computer
Between RAM and CPU
Between RAM and storage devices
Expansion Bus
Part of data bus between RAM and the peripherals

18. Expansion Slots and Cards
Cards also called expansion boards, controller cards, adapters
Desktops have 4 to 8 slots
Standard cards
Graphics or video card
Modem card
Sound card
Network card
CD video: inserting an expansion card

19. Expansion Slot Types ISA: Industry Standard Architecture
Older; modems and slow devices
PCI: Peripheral Component Interconnect
Fast; graphics, sound, video
AGP: Accelerated Graphics Port
Fast; graphics

20. PCMCIA (PC Card)
Personal Computer Memory Card International Association
Found on notebook computers
Type I, II, III

21. Expansion Ports Jacks or connectors Mouse, keyboard, serial, USB
Cables

22. Display Devices Graphics card CRT: Cathode Ray Tube
Video memory
AGP expansion card
Accelerator technology
CRT: Cathode Ray Tube
Inexpensive and dependable
LCD: Liquid Crystal Display
Expensive; found on notebooks
Limited viewing angles
Active Matrix or TFT (thin film transistor)
Info web: display devices

23. Display Device Image Quality
Screen size (13” to 21”)
Dot pitch
Distance between like-colored pixels
.26 or .23 typical (smaller is better)
Resolution
Horizontal and vertical pixels on screen
640 x 480, 800 x 600 and 1024 x 768
Color or Bit Depth
Number of colors that can be displayed
24-bit (true color) = millions of colors

24. Printer Comparison Criteria
Resolution (dpi)
Quality
vs.
Price
Materials
Cost
Info web: printer buying guide
Speed (ppm or cps)

25. Printer Types Ink Jet printer Solid Ink printer
Thermal Transfer printer
Dye Sublimation printer
Laser printer
Dot Matrix printer

26. Ink Jet Printer Nozzle-like print head sprays ink Low cost Can smudge
Color; black and white

27. Solid Ink Printer Crayon-like ink is melted and sprayed
Vibrant colors on most types of paper

28. Thermal Transfer Printer
Uses wax that is melted
Needs special paper/transparencies
Expensive

29. Dye Sublimation Printer
Like wax transfer, but uses heated dye
Need special paper
Excellent color quality
Expensive

30. Laser Printer Same technology as photocopier Fax High quality Fast
CD video: laser printer

31. Keyboards
Lab: operating a personal computer

32. Peripherals Device driver software on CD Plug and Play (PnP)
CD screentour: peripheral devices examples

33. TechTalk: Windows Registry
Registry is the glue that binds together the PC hardware, peripherals, application and system software
Operating system needs to know (and registry holds)
where peripherals are located
what has been installed
how they are configured
how you want to use them

34. Techtalk: continued
Examples: resolution, shortcuts, system events, network settings, uninstall routines
System.dat and User.dat
Registry updated when you install or remove hardware or software

35. Issue
CD: exercise
Why Recycle Computers?

36. Computer Hardware
End