Introduction to Computers

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Introduction to Computers

• How to purchase a personal computer

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What is a Computer

• Is an electronic device, operating under the
  control of instructions stored in its own memory,
  that can accept data (input), process the data
  according to specified rules (process), produce
  results (output), and store the results (storage)
  for future use.

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What does a computer do?

• All computers perform the information processing
  cycle
• input
• process
• Output
• Storage

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Data

• Collection of unprocessed items, which can
  include text, numbers, images, audio, and video

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Information

• Conveys meaning and is useful to one or more
  people.

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Computer Users (end users and users)

• People who use the computer directly or use the
  information it provides.

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Why is a computer so powerful?

• A computer derives its power from its capability
  to perform the information processing cycle with
  amazing speed, reliability (low failure rate),
  and accuracy its capacity to store huge amounts
  of data and information and its ability to
  communicate with other computers.

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How does a computer know what to do?

• For a computer to perform operations, it must be
  given a detailed set of instruction that tells it
  exactly what to do. These type of instructions
  are called a computer program or software.
• Once the program is stored, the computer can
  begin to operate by executing the programs first
  instruction.

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What are the components of a computer?

• The six primary components of a computer are
  input devices, the processor (control unit and
  arithmetic/logic unit), memory, output devices,
  storage devices, and communication devices.
• All the 6 components make up the system unit.

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Input Devices

• Is any hardware component that allows you to
  enter data, programs, commands, and user
  responses into a computer.

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The 2 primary devices are the keyboard and mouse

• Keyboard-input device that contains keys you
  press to enter data into the computer.
• Stylus-small metal or plastic device that looks
  like a ballpoint pen, but uses pressure instead
  of ink to write, draw, or make selections.
• Mouse-is a pointing device that fits comfortably
  under the palm of your hand.
• You control the movement of the pointer, often
  called the mouse pointer, on the screen and make
  selections from the screen.

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System Unit

• Is a case that contains electronic components of
  the computer used to process data.
• The motherboard, sometimes called a system board,
  is the main circuit board of the system unit.

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Processor

• Also called the central processing unit (CPU),
  interprets and carries out the basic instruction
  that operate a computer.
• The control unit interprets the instructions.
• The arithmetic/logic unit performs the logical
  and arithmetic processes.

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Memory

• Memory (random access memory or RAM) consists of
  electronic components that temporarily store
  instruction waiting to be executed by the
  processor, data needed by the those instruction,
  and the results of processed data (information).

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Amount of Memory

• The amount of memory typically is measured in
  kilobytes or megabytes.
• One kilobyte (K or KB) equals aprox. 1,000
• One megabyte (MB) equals aprox. 1 million
• One gigabyte (GB) equals aprox. 1 billion
• A memory location, or byte, usually stores one
  character such as the letter A.

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Output Devices

• Makes the information resulting from processing
  available for use.

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2 commonly used output devices

• Printers
• Display devices

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Printers

• Impact printer prints by striking an inked ribbon
  against the paper.
• Nonimpact printer, such as ink-jet printers and
  laser printers, form characters by means other
  than striking a ribbon against paper.
• Photo printers, produce photo-quality pictures
  and are ideal for home or small-business use.

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Display Devices

• Display device is an output device that visually
  conveys text, graphics, and video information.
• 2 basic types of monitors are Flat panel and CRT
• LCD monitors, the most popular type of flat panel
  monitor, uses a liquid display crystal, similar
  to a digital watch, to produce images on the
  screen.
• The surface of the screen of either a CRT or LCD
  monitor is composed of individual picture
  elements called pixels.

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Storage Devices

• Is used to store instructions, data and
  information when they are not being used in
  memory.

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Data Transfer Speed
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Magnetic Disks

• Use magnetic particles to store items such as
  data, instructions, and information on a disks
  surface.
• Formatting is the process of dividing the disk
  into tracks and sectors, so the computer can
  locate the data, instructions, and information on
  the disk.
• A track is a narrow recording band that forms a
  full circle on the surface of the disk.
• The disks storage locations consist of
  pie-shaped section, which break the tracks into
  small arcs called sectors.
• Portable storage medium means you can remove the
  medium from one computer and carry it to another
  computer.

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Hard Disks

• A hard disk, also called a hard disk drive, is a
  storage device that contains one or more
  inflexible, circular platters that magnetically
  store data, instruction , and information.
• Close clearance means that dirt, dust, smoke, or
  other particles could cause a head crash, when a
  read/write head touches a platter, usually
  resulting in loss of data or sometimes the entire
  drive.
• A backup is a duplicate of a file, program, or
  disk that you can use in case the original is
  lost, damaged, or destroyed.

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Hard Drive
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Floppy Disks

• A floppy disk or diskette is an inexpensive
  portable storage medium.
• A floppy disk drive is a device that can read
  from and write on a floppy disk.
• Access time is a time required to access and
  retrieve data.

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Optical Discs

• An optical disc is a portable storage medium that
  consists of a flat, round, portable disc made of
  metal, plastic and lacquer that is written and
  read by a laser.
• A CD-ROM (compact disc-read only memory) is a
  type of optical disc that users can read but not
  write on (record) or erase.

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To read a CD-ROM, insert the disc in a CD-ROM
drive or a CD-ROM player.
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Other Optical Discs

• A CD-R (compact-disc-recordable) is an optical
  disc onto which you can record your own items
  such as text, graphics and audio.
• A CD-RW (compact disc-rewriteable) is an erasable
  optical disc you can write on multiple times.
• A DVD-ROM (digital video disc- ROM) is a very
  high-capacity optical disc capable of storing
  from 4.7 GB to 17 GB

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To read a DVD-ROM, you need a DVD-ROM drive
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More optical discs

• DVD-R and DVDR are competing DVD-recordable
  formats, each with up to 4.7 GB storage capacity.
• Blu-ray (BD-ROM) and HD DVD are DVD
  recordable-with higher quality and more capacity.
• DVD-RW, DVDRW, and DVDRAM are competing DVD
  formats, storage capacities up to 4.7 GB per side
  allows users to erase and write many times.
• BD-RE and HD DVD-RW are higher-capacity
  rewritable DVD formats

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CD/DVD Types
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Tape

• Tape is magnetically coated ribbon of plastic
  housed in a tape cartridge capable of storing
  large amounts of data and information at a low
  cost.

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Miniature mobile storage media

• Miniature mobile storage media are rewritable
  media usually in the form of a flash memory card,
  USB flash driver or a smart card.
• Flash memory cards are solid-state media which
  means they consist entirely of electronics and
  contain no moving parts
• A USB flash drive (or pen or thumb drive) is a
  flash memory storage device that plugs into a USB
  port on a computer or mobile device.

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Types of Mini Storage Media
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Communication Devices

• A communication device is a hardware component
  that enables a computer to send and receive data,
  instructions, and information to and from one or
  more computer.
• Communications occur over transmission media such
  as telephone lines, cables, cellular radio
  networks, and satellites.

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Computer SoftwareTwo types of software are
system software and application software
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System Software

• System software consists of programs to control
  the operations of computer equipment.
• The operating system tells the computer how to
  perform the functions of loading, storing, and
  executing an application program and how to
  transfer data.
• Booting is when a computer is turned o, the
  operating system is loaded into the computers
  memory from auxillary storage.

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Other System Software

• Most operating systems have a graphical user
  interface (GUI). A GUI provides visual cues such
  as icon symbols to help the user.
• Each icon represents an application such as word
  processing, or a file or document where data is
  stored.

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Application Software

• Application software consists of programs
  designed to make users more productive and/or
  assist them with personal tasks.

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Commonly used applications include word
processing, electronic spreadsheet, database, and
presentation graphics
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Word Processing

• Word processing software is used to create, edit,
  format and print documents

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Spreadsheet

• Electronic spreadsheet software allows the user
  to add, subtract, and perform user-defined
  calculation on rows and columns or numbers.

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Database

• Database software allows the user to enter,
  retrieve, and up-date data in an organized and
  efficient manner.

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Presentation Graphics

• Presentation graphics software allows the user to
  create slides for use in a presentation to a
  group.

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Network and the Internet

• A network is a collection of computers and
  devices connected together, often wirelessly, via
  communication devices and transmission media.

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Local Area Network (LAN)

• Connects computers in a limited geographic area
  such as school computer lab, office or group of
  buildings.

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Wide Area Network

• Covers a large geographical area, such as one
  that connects the district offices of a natural
  corporation.

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Internet

• A worldwide collection of networks that connects
  millions of businesses, government agencies,
  educational institutions and indviduals.

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More than 1 billion people around the world use
the Internet to

• Communicate/meet people
• Wealth, news and research
• Shopping
• Banking investing
• Entertainment/Leisure
• games
• music
• Videos
• Books
• magazines

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Most users connect to the Internet in one of
there ways

• An internet service provider (ISP) is an
  organization, such as a cable company or
  telephone company that supplies connections to
  the internet for a monthly fee.
• An online service provider (OSP) provides access
  to the internet, but it also provides a variety
  of other specialized content and services such as
  news, weather, finance data, email, games and
  more.
• A wireless internet service provider (WISP) is a
  company that provides wireless internet access to
  computers and mobile devices such as swat phones
  and PDAs

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The World Wide Web

• World Wide Web (or the web) contains billions of
  documents and web-pages.
• A web-page is text, graphics, audio and video and
  has built-in connections, or links, to other web
  documents.
• Web-site is a related collection of web pages
• Web-browser is visitors to a web-site access and
  view web-pages using a software.
• A web page has a unique address, called a uniform
  resource locator (URL), which consists of a
  unique address.
• http// stands for hypertext transfer protocol,
  the communications standard used to transfer
  pages on the web.
• A web server is a computer that delivers
  (services) requested webpage.

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Electronic Commerce

• Electronic commerce (e-commerce) is conducted
  when you participate in business online.

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There are 3 types of e-commerce

• Business to consumer (B2C) e-commerce involves
  the scale of goods to the general public.
• Consumer to consumer (C2C) e-commerce involves
  one consumer selling directly to another.
• Business to business (B2B) e-commerce provides
  goodies and services to other businesses.

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How to Purchase a personal computer
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3 ?s to help narrow choices to a specific
computer type

• Do you want a desktop or a mobile computer?
• For what purposes will you use the computer?
• Should the computer be compatible with the
  computers _at_ work and school?

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How to purchase a desktop computer

• The steps involved in purchasing a desktop
  computer

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The steps involved in purchasing a desktop
computer

• Determine the specific software you want to use
  on your computer.
• Know the system requirements of the operating
  system.
• Look for a bundled software
• Avoid buying the least powerful computer
• Consider upgrades to the mouse, keyboard,
  monitor, printer, microphone, speakers

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The steps involved in purchasing a desktop
computer

• Determine whether you want to use phone line or
  cable access for internet
• If using dial-up or wireless-selection ISP or OSP
• Use a worksheet to compare computers and other
  parts
• Buying a new computer you have several
  purchasing options
• If you buying used stick with name brands (DELL,
  Gateway, Hewlett Packard, Apple)

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The steps involved in purchasing a desktop
computer

• Trading old one for new
• Hidden costs
• Consider more than just price
• Avoid restocking fees
• Use credit card to purchase new computer.
  Consider purchasing warranty or service plan.

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How to purchase a notebook computer

• The steps involved in purchasing a notebook
  computer

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The steps involved in purchasing a notebook
computer

• Sufficiently large active-matrix screen
• Experiment with different keyboards and point
  devices
• Has a CD and/or DVD drive
• Upgrade processor, memory and disk storage
• Availability of built-in parts and a port
  extender.

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The steps involved in purchasing a notebook
computer

• Converts to PC tablet
• Built-in wireless network connection
• Purchase a 2nd battery
• Well padded carrying case
• Electrical and telephone adaptor overseas
• Compatible with video projector
• Finger print scanner