1. Computer Skills CIS 100 http://www.just.edu.jo/~mqais/CIS%20100.html
1st semester

2. Ch.01 Introduction to Computers

3. What are computers?
Computers are electronic devices that can follow instructions to accept input, process the input and then produce information. It is a machine that manipulates data according to a set of instructions.
Computers are machines that perform tasks or calculations according to a set of instructions, or programs.
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem. (Wikipedia free encyclopedia)

4. Hardware
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5. Computers are made of
HARDWARE
SOFTWARE

6. Computers are made of
Computers work through an interaction of hardware and software.
Hardware refers to the parts of a computer that you can see and touch, including the case and everything inside it.
The most important piece of hardware the central processing unit (CPU), or microprocessor.

7. Computers are made of
Software refers to the instructions, or programs, that tell the hardware what to do.
Ex. operating system (OS), A word- processing program.

8. Hardware
A computer is a system of many parts working together. The physical parts, which you can see and touch, are collectively called hardware.
System unit: It is the core of a computer system. Usually it's a rectangular box. Inside this box are many electronic components that process information.

9. Hardware
The most important of these components is the central processing unit (CPU, or microprocessor) which acts as the "brain" of computer. The CPU has two main components, namely:
Control Unit (CU): controls the fetching of instructions from the main memory and the subsequent execution of these instructions. Among other tasks carried out are the control of input and output devices and the passing of data to the Arithmetic/Logical Unit for computation.

10. Arithmetic/Logical Unit (ALU): carries out arithmetic operations on integer (whole number) and real (with a decimal point) operands. It can also perform simple logical tests for equality and greater than and less than between operands.

11. Mother-Board (or Main Board)
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CPU
RAM
ROM

12. Primary Memory
Memory (fast, expensive, short-term memory): Enables a computer to store, at least temporarily, data, programs, and intermediate results.
Two general parts:
RAM
ROM

13. RAM (Main Memory) its a primary storage or random access memory (RAM).
it temporarily holds data and programs for use during processing (volatile: information stored in RAM is lost when the computer is turned off). The more information being processed the more RAM the computer needs.
RAM consists of locations or cells. Each cell has a unique address which distinguishes it from other cells.

14. Address
Memory locations 1 2 3 n
Memory Cell
Main Memory

15. Main Memory

16. ROM: Read Only Memory ROM is part of memory
Programmed at manufacturing time
Its contents cannot be changed by users
It is a permanent store

17. Other Kind of Memory
PROM: Programmable Read Only Memory.
EPROM: Erasable Programmable Read Only Memory
Cache Memory
Registers: not part of the main memory.

18. Input Devices
Translate data from form that humans understand to one that the computer can work with
Most common are keyboard and mouse
Selector Buttons

19. Examples of Input Devices
Keyboard (QWERTY keyboard, ATMs keyboard)
ATM: automatic teller machine
Mouse
Scanner
Optical mark recognition (Light Pin , Bar code scanners)
Microphone
Joystick .

20. Examples of Input Devices(2)
Point and Draw devices
Trackball
Touchpad
Touch screen
Magnetic stripes and smart cars.
Digital Cameras

22. Secondary Storage
Stores data and programs permanently: its retained after the power is turned off
Examples
Hard Drive (Hard Disk)
Located outside the CPU, but most often contained in the system cabinet
Floppy Disk
Optical Laser Discs
CD-ROM, CD-RW, and DVD

23. Kinds of Disk Drives

24. Common Secondary Media
Diskettes
Data represented as magnetic spots on removable flexible plastic disks
Most common size is 3 1/2 inches, in a rigid plastic case
Disk drive holds the diskette, reads or retrieves the data and writes or stores data

25. Common Secondary Media
Hard drive
Data is represented magnetically as with diskettes
Normally more than one rigid platter in a sealed unit
These disks are not removable
Significantly more capacity and faster operating than diskettes

26. Common Secondary Media
Hard drive

27. Common Secondary Media
Optical Laser Discs
CD ROM & DVD’s
Data is represented as pits and lands
Some kinds are read only (CD-ROM) and some Kinds are rewritable (CD- RW)
Significantly more capacity and faster operating than diskettes
DVD: Digital Video Disk

28. Approximate printed 8.5 x 11 inch pages
Common Secondary Media
Approximate printed 8.5 x 11 inch pages
Amount of storage
Disk size
180 pages
360 Kb
5.25 low density
360 pages
720 Kb
3.5 low density
600 pages
1.2 Mb
5.25 high density
720 pages
1.44 Mb
3.5 high density
a small library
700 MB CD
a feature length movie
4.7 GB /8.5 GB
DVD

29. Common Secondary Media
tapes
Panasonic's LS inch diskettes
Iomega's Zip & Jazz disks
VCR tape (Video Cassette Recorder )
Flash USB disks
MMC (Multi Media Card ) SD

30. CPU
Output Devices
Pieces of equipment that translate the processed information from the CPU into a form that humans can understand.
Processed
information

31. Sound Blasters (Sound Card By Creative Lab) Controlling other devices
Output Devices
Monitors
Printers
Dot matrix printers
Ink jet printers
Laser printers
Sound Blasters (Sound Card By Creative Lab)
Controlling other devices

32. Software
A collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it.

33. Types of software
1- System software: helps run the computer hardware and computer system. 2- Application software: allows end users to accomplish one or more specific (not directly computer development related) tasks. 3- Programming software : usually provides tools to assist a programmer in writing computer programs, and software using different programming languages in a more convenient way.

34. System Software
The software that controls everything that happens in a computer.
Background software, manages the computer’s internal resources
Resources examples : CPU, RAM , I/O devices, …

35. Among other things, the operating system:
All hardware and software are under the control of the operating system.
Among other things, the operating system:
Determines how valuable RAM is allotted to programs.
Performs tasks related to file management.
Sets priorities for handling tasks.
Manages the flow of instructions, data and information to and from the processor (CPU).

36. Examples of Microcomputer Operating System Software
DOS - original standard for IBM compatibles
Windows - a graphical operating environment
Windows VISTA, XP, millennium, 2000, 98, and 95
Continue …

37. Examples of Microcomputer Operating System Software Cont.
Windows NT - for powerful workstations & networks
OS/2 - competitor to Windows 2000
Macintosh Operating System
Unix - originally for minicomputers, now used on microcomputers and Internet servers

38. Application Software Packaged Custom
Packaged - “off the shelf”, pre-written programs ( General purpose)
Custom - written for an organization’s specific purpose (Special purpose)

39. Application Software – Basic Tools
Word processors– example: Microsoft word
Spreadsheets-- example: Microsoft Excel
Database managers-- example: Microsoft Access
Graphics-- example: Photoshop

40. Units of Measurements Bit (Binary Digit)(takes two values: 1 or 0)
Byte = 8 bits
KB (Kilo-byte) = 1024 bytes
MB (mega-byte) = 1024 KB
GB (giga-byte) = 1024 MB
TB (Tera-byte) = 1024 GB
Remark: 1024=210
Units of Measurements

41. Four Kinds of Computers
Microcomputers
2. Minicomputers
3. Mainframe computers
4. Supercomputers

42. Comparison between the previous kinds of computers may made based on :
Price
Processing Speed
Storage Capacity
Powerful
Single-user or Multi-user
Supporting hundreds (or thousands) of users simultaneously
Computer Size
Companies size
…etc.

43. Microcomputer =>Personal Computer => PC
Personal Computer (PC): A small, single-user computer based on a microprocessor.
Microcomputers

44. Desktop Computer Small enough for a desktop, but not easily portable
Personal computers (PC’s) run general purpose software and are employed by a wide spectrum of users

45. Portable Computers
Easily transported from one place to another

46. Four categories Portable Computers Laptops Notebooks Sub-notebooks
Personal Digital Assistants (PDA)

47. PDA

49. Minicomputers
A multi-user computer capable of supporting up to hundreds of users simultaneously.
Desk-sized
More processing speed and storage capacity than microcomputers
General data processing needs at small companies
Larger companies use them for specific purposes

50. Mainframe Computers
A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.
Larger machines with special wiring and environmental controls
Faster processing and greater storage than minicomputers
Typical machine in large organizations

51. Supercomputers
An extremely fast computer that can perform hundreds of millions of instructions per second.
The most powerful of the four categories
Used by very large organizations, particularly for very math-intensive types of tasks

52. Characteristics of Computers
1- Store a large amount of data and information for a long period of time.
2- process data and information in high accuracy level .
3- Speed in processing data information.
4- Sharing of information / network.

53. Understanding the difference between Data, Information and Knowledge:
Computer
Data
Information
Knowledge

54. Data: is the name given to basic facts such as names and numbers.
Information: is data that has been converted into a more useful or intelligible form.
Knowledge: arrangement of information and classifying information of the same type or the same topic.

55. e. g.
(data) | | sort \ / (information)

56. Data
Document files
Worksheet files
Database files

57. Processing data produces information, and processing information produces knowledge.

58. Computer Viruses

59. Computer Viruses
A computer virus are small software programs that are designed to spread from one computer to another and to interfere with computer operation.
A virus might corrupt or delete data on your computer, use your program to spread itself to other computers, or even erase everything on your hard disk.

60. Types of Computer Viruses
Macro Viruses
Network Viruses
•Trojan Horses
Logic Bombs
Companion Viruses
Boot Sector Viruses
Multipartite Viruses

61. Types of Computer Viruses
Macro Viruses
A macro virus, often scripted into common application programs such as Word or Excel, is spread by infecting documents.
Network Viruses
rapidly spreads through a Local Network Area (LAN), and sometimes throughout the internet.
•Trojan Horses
The Trojan virus once on your computer, doesn't reproduce, but instead makes your computer susceptible to malicious intruders by allowing them to access and read your files. Making this type of virus extremely dangerous to your computer's security and your personal privacy.

62. Types of Computer Viruses
Logic Bombs
a piece of code that are inputted into a software system. When a certain and specific condition is met, such as clicking on an internet browser or opening a particular file, the logic bomb virus is set off.
Companion Viruses
takes advantage of MS-DOS. This virus creates a new file with typically the .COM extensions, but sometimes the .EXD extension as well.

63. Types of Computer Viruses
Boot Sector Viruses
generally hide in the boot sector, either in the bootable disk or the hard drive. Unlike most viruses, this virus does not harm the files in the hard disk, but harm the hard disk itself.
Multipartite Viruses
spreaded through infected media and usually hides in the memory. Gradually, the virus moves to the boot sector of the hard drive and infects executable files on the hard drive and later across the computer system.

64. Sources of Computer Viruses
Three primary sources
The Internet
Via downloads and exchanges
Diskettes
Exchanging disks
Computer networks
Can spread from one network to another

65. How do you know if you have a virus?
Lack of storage capability
Decrease in the speed of executing programs
Unexpected error messages
Halting the system

66. Virus Protection
The software package distributed with new PCs always includes an antiviral program. The best way to cope with viruses is to recognize their existence and use an antiviral, or antivirus program.

67. Some tips that will help minimize your vulnerability to viruses:
Delete s from unknown or suspicious, untrustworthy (unreliable) sources, especially those with files attached to an .
Never open a file attached to an unless you know what it is, even if it appears to come from a friend.
Download files from the Internet only from legitimate and reputable sources.

68. Update your antivirus software at least every two weeks as over 200 viruses are discovered each month.
Backup your files periodically
Traditionally virus protection has been at the PC or client level. However, this may change as companies look to network and Internet service providers for more services.