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TRANSCRIPT
Created by S Cox
Objectives
Explain the basic differences between Macintosh and Windows computers
Describe what devices are used for entering information into computer systems
Discuss different kinds of input and output devices for multimedia
Compare different kinds of storage devices and discuss their advantages and disadvantages
Describe the computer parts that process data
Learn how computers are connected locally and around the world
Learning About Computers
PCs are computers that can be:• Used by individuals at home, work, or school
• Desktop models or portable laptop models
• Connected to a server in a network
One of the principal differences among computers is the operating system. • Operating systems enable computers to run
software and perform basic tasks.
• Most personal computers use Windows or Macintosh (MacOS) operating systems.
• Windows and MacOS operating systems are not compatible.
Learning About Computers
Difference between desktop and laptop
computers:
Desktop computers are meant to be left in
one location and laptops are portable
Personal digital assistants –
computers that are small enough to hold
in the palm of your hand
Today’s PDAs are just about as smart as a
desktop or laptop computer
Learning About Computers
A server is a computer that manages
files and other resources for a network
Some are no bigger than a PC, others are
larger and more powerful
Input Devices
Input is any information you enter into a
computer
Keyboard – used to enter text
Mouse - used to select options by pointing
and clicking items on the display screen
Keypads – used by touching the characters
with a stylus rather than typing
Input Devices
Cursor – symbol on the screen that points to specific information
Trackball – a popular variation on the mouse…instead of moving the mouse you move a ball that is set in a stationary holder.
Advantage – puts less strain on the arms and uses less desk surface
Touchpad – a flat, built-in pad…press and move your finger on the touchpad to move the cursor
Input Devices
Sound input devices Microphones
Digital recorders
Synthesizers (device for translating musical notes into a digital format for computer input and processing) and musical keyboards
Digital Cameras Digital Still Cameras - pictures
Digital Camcorders – record video and sound
Webcams – digital video camera connected to the Web
Input Devices
Graphics tablets – also called
digitizing tablet or digitizer;
used to create sketches and
drawings in digital format
Scanners – used to convert any printed picture or
document to a digital file to upload to a computer
Optical character recognition (OCR) – software used to convert
scanned text from a paper document or a graphic file into a format
that can be edited on a computer
Joysticks – used to send instructions to the computer
through a directional lever and one or more control
buttons typically used for games
Output and Display Devices
Output – Any information that a computer produces
Monitors – display screen Cathode ray tube (CRT) – resembles a TV; an
electron beam continuously scans the back of the screen to create images by lighting up phosphor
Liquid-crystal display (LCD) – works like a calculator display; applies voltage to liquid crystals which are sandwiched between to magnetic, to light them up; represent color by varying the amount of light that shines through
Output and Display Devices
Monitors depend on a graphics card (circuit board for processing and displaying graphics)
Touch Screen – output device, a display, and an input device; ATMs and PDAs use them; used when peripherals (device that is used with a computer but not essential) are inconvenient
Output and Display Devices
Plasma Displays – flat-panel; creates
images by passing electrical impulses
through a neon/xenon gas mixture
sandwiched between two sealed glass
plates with electrodes on their surface
LEDs – screens that light up when
electricity passes through them like
PDAs or cell phones
Projectors
Output and Display Devices
Printers
Ink-jet – spray ink at the paper through tiny
nozzles
Laser – uses a laser beam and magnetism
to transfer fine powder called toner to the
paper; similar to a copier
LCD and LED – use magnetism and toner,
but instead of beams they use liquid crystals
and light-emitting diodes
Speakers – computer needs audio card
Digital Storage Devices
Hard drives – built in for storing
software and information
Stores information magnetically
Has an arm with a sensor on the end that
reads and writes data as it spins
Digital Storage Devices
Removable storage
CDs – disc used to store and read digital material
CD-ROM – can only read data but cannot write to the disc
DVDs – optical disks
Floppy disks – flexible magnetic disk…becoming obsolete
Zip disks – developed by Iomega Corporation
Memory cards – small removable digital input modules; used by cameras and audio recorders
USB memory drives – also called travel drives, jump drives, memory sticks, or thumb drives
Processing Components
Processing includes all the calculations
and other operating a computer
performs on your input to turn it into
output.
Processing takes place on
microprocessors, or chips (usually
smaller than a
fingernail, contains millions of
electronic components)
Processing Components
Central Processing Unit – controls the computer’s logic and its ability to carry out instructions; used by almost all digital devices (alarm clocks, digital cameras, and CD players)
Vary in processing speed; measured in megahertz (MHz) or gigahertz (GHz)…the faster the speed the faster your programs will run
Part of the motherboard (main circuit board)
Memory
Random Access Memory (RAM) – where the computer stores data while you are working on it
○ Measured in bytes
Elements of Communication
In order to exchange files and share
resources, computers:
Require special input and output devices
Must be part of a network, such as:
○ The Internet
○ Local area network (LAN) – connect
computers in one location
○ Wide area network (WAN)– connects
computers across a wide geographical area
Elements of Communication
Types of connections
Dial-up connection – a computer uses a modem and a
standard telephone line…obsolete
Broadband connection – uses dedicated telephone
lines or cable television equipment …constant
connection
○ Some use DSL (digital subscriber lines) – high capacity
telephone lines;
the computer must be within a few miles of a telephone company
transmitter
○ No DSL – can use cable television or satellite television
companies
Elements of Communication
Devices for Communications
Modems and Broadband Connections –
cable modem
Modems and Wireless Connections – some
modems are wireless and use cellular
telephone technology
Network cards – to connect to a network a
PC needs a network interface card (NIC)
Routers – used to connect two or more
LANs