The Digital Revolution

Convergence

Digital Society

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

Digital electronics use electronic circuits to represent data

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

The second phase of the digital revolution materialized when the Internet was opened to public use

A computer network is a group of computers linked by wired or wireless technology to share data and resources

The Web 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

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

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 refers to the ownership of certain types of information, ideas, or representations

Digital technology is an important factor in global and national economies, in addition to affecting the economic status of individuals

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

Computer Basics

Personal Computers, Servers, Mainframes, and Supercomputers

PDAs, Portable Players, and Smart Phones

Microcontrollers

A computer is a multipurpose device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions

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

Memory is an area of a computer that temporarily holds data waiting to be processed, stored, or output

Storage is the area where data can be left on a permanent basis when it is not immediately needed for processing

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

A stored program means that a series of instructions for a computing task can be loaded into a computer’s memory

Application software is a set of computer programs that helps a person carry out a task

The primary purpose of system software is to help the computer system monitor itself in order to function efficiently

A personal computer is a microprocessor-based computing device designed to meet the computing needs of an individual

Personal Computers, Servers, Mainframes, and Supercomputers

The term workstation has two meanings:

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

Personal Computers, Servers, Mainframes, and Supercomputers

The purpose of a server is to serve computers on a network (such as the Internet or a home network) by supplying them with data

A mainframe computer (or simply a mainframe) is a large and expensive computer capable of simultaneously processing data for hundreds or thousands of users

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

Personal Computers, Servers, Mainframes, and Supercomputers

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

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

Digital Data Representation

Data Representation Basics

Representing Numbers, Text, and Pictures

Quantifying Bits and Bytes

Circuits and Chips

Data representation refers to the form in which data is stored, processed, and transmitted

Digital devices work with distinct and separate data

Analog devices work with continuous data

Numeric data

Character data

Digitizing is the process of converting analog data into digital format

An integrated circuit (computer chip) is a super-thin slice of semiconducting material packed with microscopic circuit elements

Bits take the form of electrical pulses that can travel over circuits

System board

Programs and Instruction Sets

Processor Logic

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, like the one above, created in a high-level language by a programmer is called source code

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 the processor’s circuitry

The end product is called machine code

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 instruction, the op code means add and the operand is 1, so the instruction means Add 1.

The ALU (arithmetic logic unit) is the part of the microprocessor that performs arithmetic 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

The term instruction cycle refers to the process in which a computer executes a single instruction

Authentication Protocols

Password Hacks

Password Security

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

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

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

Strive to select a unique user ID that you can use for more than one site

Maintain two or three tiers of passwords

A password manager is utility software that generates secure passwords and stores them along with user IDs and their corresponding sites

Section A: Personal Computer Basics

Section B: Microprocessors and Memory

Section C: Storage Devices

Section D: Input and Output Devices

Section E: Hardware Security

Personal Computer Basics

Personal Computer Systems

Desktop and Portable Computers

Home, Media, Game, and Small Business Systems

Buying Computer System Components

The term form factor refers to the size and dimensions of a component, such as a system board or system unit

A desktop computer fits on a desk and runs on power from an electrical wall outlet

A portable computer is a small, lightweight personal computer

A notebook computer (also referred to as a laptop), is a small, lightweight portable computer that opens like a clamshell to reveal a screen and keyboard

A tablet computer is a portable computing device featuring a touch-sensitive screen that can be used as a writing or drawing pad

An ultra-mobile PC (UMPC) is a small form factor tablet computer designed to run most of the software available for larger portable computers

A home computer system offers a hardware platform with adequate, but not super-charged support for most computer applications

A Media Center PC officially uses Windows Media Center Edition operating system

Some of the most cutting-edge computers are designed for gaming

Computers marketed for small business applications tend to be middle-of-the-line models pared down to essentials

Decide how your computer will be used, and how much you want to spend

Decide on a platform (Mac, PC, Linux)

Look at ads in computer magazines and at computer/electronic stores

Understand the computer jargon

Expect to pay anywhere from a few hundred to several thousand dollars

Instead of buying a new computer, you might consider upgrading

Microprocessor Basics

Today’s Microprocessors

Random Access Memory

Read-only Memory

EEPROM

A microprocessor is an integrated circuit designed to process instructions

ALU

Registers

Control unit

Instruction set

Front side bus

HyperTransport

Microprocessor clock

Megahertz

Gigahertz

Word size

Cache

Level 1 cache (L1)

Level 2 cache (L2)

CISC vs. RISC
technology

Serial processing

Pipelining

Parallel processing

Dual core processor

Hyper-Threading Technology

Random Access Memory is a temporary holding area for data, application program instructions, and the operating system

Microscopic capacitors hold the bits that represent data

Most RAM is volatile

Requires electrical power to hold data

RAM capacity is expressed in megabytes or gigabytes

Personal computers typically feature between 256MB and 2GB of RAM

An area of the hard disk, called virtual memory, can be used if an application runs out of allocated RAM

RAM speed is often expressed in nanoseconds or megahertz

SDRAM is fast and relatively inexpensive

DDR

RDRAM is more expensive, and usually found in high-performance workstations

ROM is a type of memory circuitry that holds the computer’s startup routine

Permanent and non-volatile

The ROM BIOS tells the computer how to access the hard disk, find the operating system, and load it into RAM

Electrically Erasable Programmable Read-Only Memory

More permanent than RAM, and less permanent than ROM

Requires no power to hold data

Storage Basics

Magnetic Disk and Tape Technology

CD and DVD Technology

Solid State Storage

Storage Wrap-up

A storage medium contains data

A storage device records and retrieves data from a storage medium

Data gets copied from a storage device into RAM, where it waits to be processed

Processed data is held temporarily in RAM before it is copied to a storage medium

Magnetic storage stores data by magnetizing microscopic particles on the disk or tape surface

A controller positions the disk and read-write heads to locate data

SATA

Ultra ATA

EIDE

SCSI

Not as durable as many other storage technologies

Head crash

A floppy disk is a round piece of flexible Mylar plastic covered with a thin layer of magnetic oxide and sealed inside a protective casing

A tape drive is a device that reads data from and writes data to a long stream of recordable media similar to the tapes used in audio cassettes

A tape is a sequential storage
medium

Optical storage stores data as microscopic light and dark spots on the disk surface

CD and DVD storage technologies

Today’s DVD drives typically have 16X speeds for a data transfer rate of 177.28 Mbps

Three categories of
optical technologies

Read-only (ROM)

Recordable (R)

Rewritable (RW)

CD-DA

DVD-Video

CD-ROM

DVD-ROM

CD-R

DVD+R or DVD-R

CD-RW

DVD+RW or DVD-RW

Solid state storage technology stores data in an erasable, rewritable circuitry

Non-volatile

Card reader may be required
to read data on solid state
storage

A USB flash drive is a portable storage device that plugs directly into a computer’s USB port using a built-in connector

A U3 drive is a special type of USB flash drive that is preconfigured to autoplay when it is inserted into a computer

Basic Input Devices

Display Devices

Printers

Installing Peripheral Devices

Keyboard

Pointing device

Pointing stick

Trackpad

Trackball

Joystick

Touch screen

A CRT display device uses a bulky glass tube

An LCD manipulates light within a layer of liquid crystal cells

Plasma screen technology illuminates lights arranged in a panel-like screen

Viewable image size

Dot pitch

Viewing angle width

Refresh rate

Color depth

Resolution

VGA, SVGA, XGA, SXGA, UXGA, and WUXGA

Graphics circuitry generates the signals for displaying an image on the screen

Integrated graphics

Graphics card

Graphics processing
unit (GPU)

An ink-jet printer has a nozzle-like print head that sprays ink onto paper

A laser printer works like a photocopier

Dot matrix printers produce characters and graphics by using a grid of fine wires

The wires strike a ribbon and the paper

Printer features

Resolution

Print speed

Duty cycle

Operating costs

The data bus moves data within the computer

Expansion cards are small circuit boards that give the computer additional capabilities

Expansion slot

PCMCIA slot

An expansion port passes data in and out of a computer or peripheral device

Peripheral device may include the Plug and Play feature, or require a device driver

Anti-theft Devices

Surge Protection and Battery Backup

Basic Maintenance

Troubleshooting and Repair

A power surge is a sudden increase or spike in electrical energy, affecting the current that flows to electrical outlets

A surge strip is a device that contains electrical outlets protected by circuitry that blocks surges and spikes

A UPS is a device that not only provides surge protection, but also furnishes your computer with battery backup power during a power outage

Computer component failures can be caused by manufacturing defects and other circumstances beyond your control

Keep the keyboard clean

Clean your computer screen on a regular basis

Keep the area clean around your computer

Make sure fans are free of dust

There are several telltale signs that your computer is in trouble

Failure to power up

Loud beep

Blue screen of death

Help and Support Center

Safe Mode