1. Computers and Digital Basics Chapter 1

2. 1 Chapter 1: Computers and Digital Basics2 Chapter Contents  Section A: All Things Digital  Section B: Digital Devices  Section C: Digital Data Representation  Section D: Digital Processing  Section E: Password Security

3. 1 SECTION A Chapter 1: Computers and Digital Basics3 All Things Digital  The Digital Revolution  Convergence  Digital Society

4. 1 Chapter 1: Computers and Digital Basics4 The Digital Revolution social, political, and economic  The digital revolution is an ongoing process of social, political, and economic change brought about by digital technology, such as computers and the Internet  A constellation of technologies, including digital electronics, computers, communications networks, the Web, and digitization are fueling the digital revolution

5. 1 Chapter 1: Computers and Digital Basics5 The Digital Revolution bits? bytes?  Digital electronics use electronic circuits to represent data (bits? bytes?)  Today, digital electronic devices include computers, portable media players such as iPods, digital cameras and camcorders, cell phones, radios and televisions, GPSs, DVD and CD players, e-book readers, and arcade games

6. 1 Chapter 1: Computers and Digital Basics6 The Digital Revolution Household Ownership of Personal Computers in the U.S.

7. 1 Chapter 1: Computers and Digital Basics7 The Digital Revolution Internet  The second phase of the digital revolution materialized when the Internet was opened to public use –E-mail –Bulletin boards –Chat groups –Blogs –Online social networks

8. 1 Chapter 1: Computers and Digital Basics8 The Digital Revolution  A computer network is a group of computers linked by wired or wireless technology to share data and resources (what is the Internet?)  The Web (www) is a collection of linked documents, graphics, and sounds that can be accessed over the Internet  Cyberspace is a term that refers to entities that exist largely within computer networks  Digitization is the process of converting text, numbers, sound, photos, and video into data that can be processed by digital devices

9. 1 Chapter 1: Computers and Digital Basics9 Convergence  Technological convergence is a process by which several technologies with distinct functionalities evolve to form a single product  Convergence tends to offer enhanced functionality and convenience

10. 1 Chapter 1: Computers and Digital Basics10 Convergence

11. 1 Chapter 1: Computers and Digital Basics11 Digital Society  Digital technologies and communications networks make it easy to cross cultural and geographic boundaries  Anonymous Internet sites, such as Freenet, and anonymizer tools that cloak a person’s identity, even make it possible to exercise freedom of speech in situations where reprisals might repress it  Citizens of free societies have an expectation of privacy  Intellectual property  Intellectual property refers to the ownership of certain types of information, ideas, or representations

12. 1 Chapter 1: Computers and Digital Basics12 Digital Society  Digital technology is an important factor in global and national economies, in addition to affecting the economic status of individuals economic interdependence  Globalization can be defined as the worldwide economic interdependence of countries that occurs as cross-border commerce increases and as money flows more freely among countries  Individuals are affected by the digital divide, a term that refers to the gap between people who have access to technology and those who do not  Digital technology permeates the very core of modern life

13. 1 Chapter 1: Computers and Digital Basics13 Quick Quiz 1.The ______________ is an ongoing process of social, political, and economic change brought about by digital technology, such as computers and the Internet. 2.True/False: Bulletin boards are personal journals posted online for general public access. 3._______ property refers to the ownership of certain types of information, ideas, or representations. a.Digital b.Intellectual c.Online d.Licensed Digital Revolution

14. 1 SECTION B Chapter 1: Computers and Digital Basics14 Digital Devices  Computer Basics  Personal Computers, Servers, Mainframes, and Supercomputers  PDAs, Portable Players, and Smart Phones  Microcontrollers

15. 1 Chapter 1: Computers and Digital Basics15 Computer Basics  A computer is a multipurpose device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions

16. 1 Chapter 1: Computers and Digital Basics16 Computer Basics  Computer input is whatever is typed, submitted, or transmitted to a computer system  Output is the result produced by a computer  Data refers to the symbols that represent facts, objects, and ideas  Computers manipulate data in many ways, and this manipulation is called processing –Central Processing Unit (CPU) –Microprocessor

17. 1 Chapter 1: Computers and Digital Basics17 Computer Basics  Memory  Memory is an area of a computer that temporarily holds data waiting to be processed, stored, or output  Storage  Storage is the area where data can be left on a permanent basis when it is not immediately needed for processing (examples?) file  A file is a named collection of data that exists on a storage medium  The series of instructions that tells a computer how to carry out processing tasks is referred to as a computer program –Software

18. 1 Chapter 1: Computers and Digital Basics18 Computer Basics  A stored program is a series of instructions for a computing task can be loaded into a computer’s memory and executed by the computer to perform a task or tasks –Allows you to switch between tasks –Distinguishes a computer from other simpler devices Examples?

19. 1 Chapter 1: Computers and Digital Basics19 Computer Basics  Application software is a related set of computer programs that helps a person carry out a task and get work done on a computer  System software allows the computer to operate (basic tasks) and monitor itself in order to function efficiently –Operating system (OS)

20. 1 Chapter 1: Computers and Digital Basics20 Personal Computers, Servers, Mainframes, and Supercomputers  A personal computer is a microprocessor- based computing device designed to meet the computing needs of an individual

21. 1 Chapter 1: Computers and Digital Basics21 Personal Computers, Servers, Mainframes, and Supercomputers  The term workstation has two meanings: –An ordinary personal computer that is connected to a network –A powerful desktop computer used for high- performance tasks

22. 1 Chapter 1: Computers and Digital Basics22 Personal Computers, Servers, Mainframes, and Supercomputers  A videogame console, such as Nintendo’s Wii, Sony’s PlayStation, or Microsoft’s Xbox, are not generally referred to as personal computers because of their history as dedicated game devices

23. 1 Chapter 1: Computers and Digital Basics23 Personal Computers, Servers, Mainframes, and Supercomputers serverclient  The purpose of a server is to serve client computers on a network (such as the Internet or a home network) by supplying them with data or application support mainframe  A mainframe computer (or simply a mainframe) is a large and expensive computer capable of simultaneously processing data for hundreds or thousands of users supercomputer  A computer falls into the supercomputer category if it is, at the time of construction, one of the fastest computers in the world –A compute-intensive problem is one that requires massive amounts of data to be processed using complex mathematical calculations What is an input/output-intensive problem?? Examples??

24. 1 Chapter 1: Computers and Digital Basics24 Personal Computers, Servers, Mainframes, and Supercomputers

25. 1 Chapter 1: Computers and Digital Basics25 PDAs, Portable Players, and Smart Phones  A PDA (personal digital assistant) is a pocket-sized digital appointment book with a small qwerty keyboard or a touch- sensitive screen, designed to run on batteries and be used while holding it  A handheld computer is essentially a PDA enhanced with features such as removable storage, e-mail, Web access, voice communications, built-in camera, and GPS  A smart phone, which in addition to voice communication, includes features such as full qwerty keypad, text messaging, e-mail, Web access, removable storage, camera, FM radio, digital music player, and software options for games, financial management, personal organizer, GPS, and maps  iPods and similar devices are classified as portable media players because their main strength is playing music, showing videos, and storing photos

26. 1 Chapter 1: Computers and Digital Basics26 PDAs, Portable Players, and Smart Phones

27. 1 Chapter 1: Computers and Digital Basics27 Microcontrollers  A microcontroller is a special-purpose microprocessor that is built into the machine it controls  Microcontrollers can be embedded in all sorts of everyday devices Examples?

28. 1 Chapter 1: Computers and Digital Basics28 Quick Quiz 1.A (n) ______________ is a special-purpose microprocessor that is built into the machine it controls. 2.True/False: Just about any personal computer, workstation, mainframe, or supercomputer can be configured to perform the work of a server. 3.Any software or digital device that requests data from a server is referred to as a(n) _______. a.minicomputer b.client c.mainframe d.terminal microcontroller

29. 1 SECTION C Chapter 1: Computers and Digital Basics29 Digital Data Representation  Data Representation Basics  Representing Numbers, Text, and Pictures  Quantifying Bits and Bytes  Circuits and Chips

30. 1 Chapter 1: Computers and Digital Basics30 Data Representation  Data representation refers to the form in which data is stored, processed, and transmitted  Digital devices work with distinct and separate data (discrete, on/off)  Analog devices work with continuous data

31. 1 Chapter 1: Computers and Digital Basics31 Representing Numbers, Text, and Pictures  Numeric data –Binary number system  Character data –ASCII, Extended ASCII, EBCDIC, and Unicode  Digitizing is the process of converting analog data into digital format  Bit = Binary Digit –on or off, 1 or 0 Sound waves….. Images….

32. 1 Chapter 1: Computers and Digital Basics32 Data Representation Extended ASCII?

33. 1 Chapter 1: Computers and Digital Basics33 Quantifying Bits and Bytes

34. 1 Chapter 1: Computers and Digital Basics34 Circuits and Chips  An integrated circuit (computer chip) is a super-thin slice of semiconducting material packed with microscopic circuit elements

35. 1 Chapter 1: Computers and Digital Basics35 Circuits and Chips  Bits take the form of electrical pulses that can travel over circuits  System board

36. 1 SECTION D Chapter 1: Computers and Digital Basics36 Digital Processing  Programs and Instruction Sets  Processor Logic

37. 1 Chapter 1: Computers and Digital Basics37 Programs and Instruction Sets  Computers, portable media players, handheld computers, and smart phones all work with digital data  Computer programmers create programs that control digital devices. These programs are usually written in a high-level programming language  The human-readable version of a program, created in a high-level language by a programmer is called source code Examples of high-level programming languages?

38. 1 Chapter 1: Computers and Digital Basics38 Programs and Instruction Sets

39. 1 Chapter 1: Computers and Digital Basics39 Programs and Instruction Sets  A collection of preprogrammed activities a microprocessor is hardwired to perform is called an instruction set  The list of codes for a microprocessor’s instruction set, called machine language, can be directly executed by that processor’s circuitry (Note: machine language is specific/unique to a given microprocessor architecture)  The end product is called machine code –1s and 0s

40. 1 Chapter 1: Computers and Digital Basics40 Programs and Instruction Sets  An op code (short for operation code) is a command word for an operation such as add, compare, or jump.  The operand for an instruction specifies the data (or the address of the data) for the operation.  In the following example, the op code might mean Add and the operand is 1, so the instruction means Add 1! 000000100 00000001 Op codeOperand

41. 1 Chapter 1: Computers and Digital Basics41 Programs and Instruction Sets A simple few lines of source code in a high-level programming language often results in multiple machine language instructions.

42. 1 Chapter 1: Computers and Digital Basics42 Processor Logic  The ALU (arithmetic logic unit) is the part of the microprocessor that performs arithmetic and logical operations  The ALU uses registers to hold data that is being processed  The microprocessor’s control unit fetches each instruction, just as you get each ingredient out of a cupboard or the refrigerator (control/flow operations)  The term instruction cycle refers to the process in which a computer executes a single instruction

43. 1 Chapter 1: Computers and Digital Basics43 Processor Logic

44. 1 Chapter 1: Computers and Digital Basics44 Processor Logic

45. 1 Chapter 1: Computers and Digital Basics45 Quick Quiz 1.A(n) __________________ is a super-thin slide of semiconducting material packed with microscopic circuit elements, such as wires, transistors, capacitors, logic gates, and resistors. 2.True/False: The machine language used by digital computers is expressed as sequences of human-readable characters. 3.A prefix which refers to a million bytes of storage is ______. a.kilo- b.giga- c.mega- d.tera- Integrated Circuit (IC)

46. 1 SECTION E Chapter 1: Computers and Digital Basics46 Password Security  Authentication Protocols  Password Hacks  Password Security

47. 1 Chapter 1: Computers and Digital Basics47 Authentication Protocols  Security experts use the term authentication protocol to refer to any method that confirms a person’s identity using something the person knows, something the person possesses, or something the person is –A person can also be identified by biometrics, such as a fingerprint, facial features (photo), or retinal pattern –A user ID is a series of characters—letters and possibly numbers or special symbols—that becomes a person’s unique identifier –A password is a series of characters that verifies a user ID and guarantees that you are the person you claim to be

48. 1 Chapter 1: Computers and Digital Basics48 Authentication Protocols

49. 1 Chapter 1: Computers and Digital Basics49 Password Hacks  When someone gains unauthorized access to your personal data and uses it illegally, it is called identity theft  Hackers can employ a whole range of ways to steal passwords  A dictionary attack helps hackers guess your password by stepping through a dictionary containing thousands of the most commonly used passwords  The brute force attack also uses password-cracking software, but its range is much more extensive than the dictionary attack

50. 1 Chapter 1: Computers and Digital Basics50 Password Hacks  If hackers can’t guess a password, they can use another technique called sniffing, which intercepts information sent out over computer networks  An even more sophisticated approach to password theft is phishing  A keylogger is software that secretly records a user’s keystrokes and sends the information to a hacker

51. 1 Chapter 1: Computers and Digital Basics51 Password Security

52. 1 Chapter 1: Computers and Digital Basics52 Password Security  Strive to select a unique user ID that you can use for more than one site  Maintain two or three tiers of passwords

53. 1 Chapter 1: Computers and Digital Basics53 Password Security  A password manager is utility software that generates secure passwords and stores them along with user IDs and their corresponding sites

54. Chapter 1 Complete Computers and Digital Basics