1. More Concepts

2. Central Processing Unit (CPU)
Designed to process instructions
ALU
arithmetic logic unit CU
control unit

3. Memory
RAM
Random Access Memory
ROM
Read Only Memory

4. RAM Random Access Memory
Temporary (volatile) holding area for data, application software and operating system
Less storage than disk
Capacity measured in MB ( MB)
Speed in nanoseconds

5. ROM Read-Only Memory Permanent on a chip from manufacturer
Holds computer start up routine, which are hard-wired instructions

6. Digital Data Representation
The form in which information is conceived, manipulated and recorded on a digital device.
Uses discrete digits/electronic signals
1,0 (bits - binary digits)
On/Off
Yes/No
Byte = 8 bits = 1 character

7. Coding Systems Depends on computer ASCII (7 bits)
Extended ASCII (8 bits - current PCs)
EBCDIC (8 bits - older IBM machines )
Unicode (16 bits - good for languages - future)

8. Quantifying Bytes and Bits
Bit = b
Nibble = Half of a byte
Byte = B
Kilobyte (KB) (1024 bytes)
Megabyte (MB) (Million bytes)
Gigabyte (GB) (Billion bytes)
Terabyte (TB) (Trillion bytes)

9. Modem Internet Connections
Dial-up connection via modem (56K)
Cable modems
Network card and cable modem required
Always-on and 25 times faster than dial-up
Infoweb: national ISPs

10. Faster Internet Connections
ISDN (Integrated Services Digital Network)
64K or 128K
Always-on and expensive
DSL (Digital Subscriber Line) and xDSL
Up to 125 times faster than dialup
DSS (Digital Satellite Service)
500K
Need proximity to a telephone switching station

11. E-mail Basics userid@computer Account = Mailbox Message Attachment
ASCII vs HTML format
Netiquette
Infoweb: netiquette
Infoweb: client software

12. E-mail System E-mail servers Store-and-forward technology Types
POP (Post Office Protocol) used via ISP
IMAP (Internet Messaging Access Protocol)
Web-based like Hotmail
Infoweb: web-based

13. Software Categories
System Software
Application Software

14. System Software Operating Systems Device Drivers Utilities Programming
Languages
DOS
Windows
Mac OS
Linux
UNIX

15. Application Software Document Production Reference Statistical
Spreadsheet
Software
Mathematical
Modeling
Entertainment
Data
Management
Accounting
& Finance
Music
Video
Educational
Graphics

16. Software Topics Computer program Support module Data module
main executable program (.exe)
Support module
called by the program (.dll)
Data module
Example: a dictionary file or a file that is not supplied by the user

17. How Computers Interpret Software
Computer languages
Source code
High-level languages: COBOL, C++, Java
Machine language
Compiler
Creates object code in single batch
Interpreter
Converts one instruction at a time
Common with web-based scripts (part of web page)

18. Operating Systems
Interacts with application software, device drivers & hardware to manage computers resources
Multitasking
CTRL-ALT-DEL
GUI
graphical user interface
Utilities

19. License vs. Copyright
Software License: a legal contract that defines the ways in which you may use a computer program.
Copyright: a form of legal protection that grants the author of an original work an exclusive right to copy, distribute, sell and modify that work.
Software piracy
For contract to take effect:
Open a shrink-wrap license product
Agree to an installation agreement
Info web: software copyright

20. Types of Copyright Protections
Shareware: try before you buy on the honor system
Freeware: no fee - can use, but not alter or sell
Open Source: uncompiled source code that can be changed - sold or free
Public Domain: can be copied, altered and resold

21. TechTalk: Boot Process
Power up
ROM runs bootstrap program
POST (Power-on self-test)
Identifies and checks peripherals
ROM loads operating system from hard disk into RAM
Checks configuration and customization startup routines
Safe Mode if this process is not successful

22. Computer File Characteristics
A collection of data on a storage medium
Filename conventions
Filename extension
.txt
.jpg
.exe
.doc

23. C:\Music\Reggae\Marley One Love.mp3
File Locations
Device drive letters A: C: D:
Directory
Root Directory (C:\)
Subdirectory or folder (C:\Documents)
File specification or Path
File size and date
Filename extension
Filename
Secondary folder
Primary folder
Drive letter
C:\Music\Reggae\Marley One Love.mp3

24. Deleting Files
Move to Recycle Bin in Windows
Undelete
Empty Bin

25. File Management Helps you organize your computer files
File/Save and File/Open
Utilities like Windows Explorer or MAC Finder
list, find, move, copy, delete, rename
Save vs. Save As

26. Logical File Storage Filing cabinet model
Metaphor to help you visualize files on a storage device
Windows Explorer
Folder hierarchy

27. Physical File Storage
Storage medium formatted into tracks /sectors electronically
File system keeps track of names and file locations.
FAT (File Allocation Table) on each disk keeps track of where all files are. If damaged, you lose everything.

28. Storage Technology Storage Medium: disk, tape, CD, DVD
holds data
Storage Device: disk drives, CD drives
mechanical device
Storage = Medium + Device

29. 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

30. 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

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

32. Comparing Storage Devices
Versatility
versatile devices can access data from several different media; i.e., DVD drive – data DVDs, DVD movies, audio CDs, etc.
Durability
mishandling, environmental factors
Speed
access time
milliseconds (ms – thousandths of a second)
random versus sequential access

33. Floppy Disk Technology
Most common
3 ½” 1.44 MB (1,440,000 bytes)
Write protect window
Others
zip disks (100 MB and 250 MB)
SuperDisks (120 MB)
Compatibility

34. CD Technology CD-ROM: Compact Disk Read-Only Memory
manufactured; cannot change; up to 680MB; more durable
CD-R: Compact Disk Recordable
you record; cannot be erased or modified
CD-RW: Compact Disk Rewritable
you record; can erase and modify

35. DVD Technology Digital Video Disk originally an alternative to VCR
Manufactured
Can play CD-ROM and most CD-Rs and CD-RWs

36. Solid State Storage USB flash drive CompactFlash (CF) cards
high-end digital cameras
MultiMedia cards (MMC)
Smaller; mobile phones, pagers, cameras
SecureDigital (SD) cards
MP3 storage

37. Display Device Image Quality
Screen size (13” to 21”)
measured diagonally
viewable image size (vis)
Dot pitch
measure of image clarity
smaller is better
Resolution
horizontal and vertical pixels displayed on the screen
640 x 480, 800 x 600, 1024 x 768 (higher is better)
Color depth (or bit depth)
number of colors that can be displayed
24-bit (true color) = millions of colors

38. Printer Comparison Criteria
Resolution (dpi)
Materials cost
Speed (ppm or cps)
Quality versus Price

39. Peripherals
device driver
Plug and Play (PnP)