Intro to Information Technology

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Intro to Information Technology

• Wednesday, September 18th
• Chapter 11 Computer Hardware
• Sites of Interest
• www.ebay.com
• www.microsoft.com
• www.pcwebopaedia.com

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Objectives

• Identify the major types, trends, and uses of
  microcomputer, midrange, and mainframe computer
  systems.
• Outline the major technologies and uses of
  computer peripherals for input, output, and
  storage.
• Identify and give examples of the components and
  functions of a computer system.
• Identify the computer systems and peripherals you
  would acquire or recommend for a business of your
  choice, and explain the reasons for your
  selections

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History of Computers
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The 1970s

• 1971 Intel makes the first microprocessor at a
  speed of 108 kHz
• The UNIX operating system was written in the new
  language, C
• One of the first personal computers, the Altair,
  came in a kit and you had to build it yourself
• 1976 The Cray-1, the worlds fastest
  supercomputer
• 1977 The debut of the Apple II, the first
  computer to have color graphics

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The 1970s continued

• 1977 The debut of the Apple II, the first
  computer to have color graphics
• The Apple II had 4 KB of RAM and cost 1298
• The Commodore PET began the line of lost cost
  Commodore PCs
• The VAX architecture was introduced in 1977 and
  cost 200000
• VisiCalc, the first spreadsheet program was
  created for the Apple II and it was the father of
  all productivity software

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The 1980s

• 1982 IBM launched its first PC, powered by DOS,
  written by a tiny company named Microsoft
• Xerox Alto the first graphical user interface,
  went on to influence Apple and Microsoft
• 1982 Commodore 64 brought affordable personal
  computing to the masses
• 1984 The Apple McIntosh
• 1984 WordPerfect the first word processor

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The 1980s continued

• 1985 The first multimedia computer, the
  Commodore Amiga
• 1986 - The Intel 80386 Processor, the first 32
  bit processor
• The C programming language
• The Apple McIntosh II the first color graphics
  McIntosh computer
• The birth of 3D graphics

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The 1990s

• Microsoft Windows 3 made PCs as easy to use as
  Apple McIntosh
• Apple sues Microsoft over the similarity of the
  graphical user interface
• AMD 386 first processor not built by Intel
• Virtual Reality

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The 1990s continued

• 1992 Linux is created
• 1993 The Intel Pentium processor
• The World Wide Web
• Windows 95 was introduced after 18 months of
  marketing
• E- Business and E-Commerce

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Computer System Categories

• Microcomputers
• Midrange Computers
• Mainframe Computers

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Microcomputers

• The most important category for business people
  and consumers
• Usually referred to as a personal computer (PC)
• Types are handheld, notebook, laptop, desktop,
  etc
• Microcomputers can perform tasks such as complex
  mathematical calculations, graphical applications
  such as computer-aided design, etc

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Microcomputers

• Network computers
• Thin client means a minimum of programs and
  processing occur on the machine itself
• Software, data storage, and operating system are
  provided by the Internet and accessed through a
  browser
• Usually does not have a local hard drive

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Microcomputers

• Information Appliances
• PDAs Personal Digital Assistant
• These have touch screens, use a stylus for
  handwriting recognition, and are usually very
  small (hand-held)
• Other appliances exist such as WebTV which allows
  you to surf the net from your TV

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Microcomputers

• Computer Terminals
• Can be dumb (limited processing) or intelligent
  (more processing)
• Intelligent terminals are found in areas such as
  transaction terminals, found in banks, stores,
  factories, etc
• Capture data on terminal, and data is managed and
  processed by servers or other computers on the
  network

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Midrange Computers

• Multi-user systems that can manage networks of
  PCs and terminals
• They are less powerful than mainframes, but more
  affordable
• Used for such tasks as network management, data
  warehouse management, and assisting mainframes
  with telecommunications, etc

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Mainframe Computers

• Large, fast, powerful
• Large storage capacities
• Used to handle processing needs for major
  corporations and government agencies
• Used for scientific calculations
• Supercomputers can have more than one processor

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Parts of a Computer

• Processing
• Input
• Output
• Memory
• Data Storage

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A Computer System
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Processing

• The heart of the computer is the Central
  Processing Unit (CPU)
• Two main divisions
• Control Unit Interprets instructions and
  directs processing
• Arithmetic-Logic Unit Performs arithmetic
  operations and performs comparisons
• Also includes circuitry for registers and cache
  memory for high speed, temporary storage

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Processing

• The clock
• This is what controls the processing in the CPU
  and at what speed it runs
• With every clock tick, the CPU executes an action
• Speed
• Usually expressed in cycles per second, or hertz.
  
• Todays computers have speeds expressed in
  megahertz (MHz), a million cycles per second, or
  gigahertz (GHz), a billion cycles per second

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Processing

• Buses
• Circuitry paths that interconnect microprocessor
  components for movement of data and instructions
• ISA Bus
• Industry Standard Architecture
• PCI Bus
• Peripheral Component Interconnect
• Used to connect peripheral devices

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Processing

• USB
• for Universal Serial Bus, an external bus
  standard that supports data transfer rates of 480
  Mbps (480 million bits per second). A single USB
  port can be used to connect up to 127 peripheral
  devices, such as mice, modems, and keyboards
• AGP
• for Accelerated Graphics Port, a new interface is
  based on PCI, but is designed especially for the
  throughput demands of 3-D graphics
• Definitions from www.pcwebopaedia.com

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Processing

• Since CPUs generate a lot of heat, a cooling
  mechanism is needed
• A metal heat sink is placed over the processor.
  It draws the heat out into its spikes
• A fan on the heat sink blows the hot air away
  from the processor

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Input

• Keyboards
• Can easily type in instructions
• Mouse
• Enables the user to point and click
• Works with a graphical user interface for easy
  navigation
• Trackball
• Similar to a mouse, but you move the ball
• Touchpad
• Move your finger on the pad to move the cursor

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Processing

• Popular types of processors
• Intel
• Pentium, Pentium II, Pentium III, Pentium IV
• Celeron
• AMD
• Athalon
• Duron

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Input

• Touch screen
• Users touch the screen to move the cursor or to
  make selections
• Pen-based computing
• Many hand-held devices use small pens to draw on
  the screen, or a designated area.
• Speech Recognition
• Users speak to a computer and it interprets their
  commands

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Input

• Optical Scanning
• Read text or graphics and convert them into
  digital input for the computer
• Reflected light patterns of the data are
  converted into electronic impulses that are
  accepted as input
• OCR or optical character recognition can be used
  to read codes or characters such as UPC codes

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Input

• Magnetic Stripe
• Iron oxide coating holds up to 200 bytes of
  information
• Digital Cameras
• Can take pictures and load them on to your
  computer
• Magnetic Ink Character Recognition
• Used on cheques for banks to sort and process
  cheques

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Input

• Serial Ports
• This is how keyboards and some older mice connect
  with the computer
• Only 1 bit of information is transmitted at a
  time
• PS/2 Ports
• Mice or keyboards connect to computers with this
  type of port
• Developed to free up a computers serial port
• Most new devices use USB ports because of their
  high speeds of data transfer and one port can
  connect up to 127 devices

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Output

• Video
• Video monitors use CRT (Cathode Ray Technology)
  similar to TVs
• Liquid crystal displays (LCD) are usually used
  for portable computers
• LCD gives a flat screen with bright colours and
  clarity
• LCD displays need less electric current and have
  a thin, flat display

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Output

• Video continued
• The quality of the video display can depend on
  the type of video card that is used
• Video cards can be plugged into either a PCI or
  AGP bus
• They have their own storage, now usually between
  16 and 32 MB
• Resolution settings also depend on the video card
• Most common resolution on a 15 monitor is
  800X600, which is the screen size measured in
  pixels

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Output

• Printers
• Dot Matrix
• Old style of printers than printed across the
  page one line at a time
• Very slow printing
• Inkjet
• Spray ink on to a page one line at a time
• Popular, low cost personal printers
• Good quality and fairly quick printing

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Output

• Printers continued
• Laser
• Use an electrostatic process similar to a
  photocopier
• Fast, high quality output in black and white
• Colour is very expensive
• Popular for businesses
• Popular printer brands include HP, Canon,
  Lexmark, and Epson

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Output

• Printers were traditionally connected to the
  computer by a parallel port
• Parallel ports have 25 pins and transmit more
  than one bit per second (unlike serial ports)
• Now many printers connect through the USB bus

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Memory

• Sizes of memory
• One Bit one character, either a one or a zero.
• This is the simplest information that a computer
  can process
• Binary expresses data in terms of a sequence of
  1s and 0s
• 1s and 0s correspond to On/Off, True/False, 5
  volts/0 volts

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Memory

• Sizes of memory continued
• A byte is 8 bits
• A nibble is 4 bits
• A KB, or kilobyte, is 1024 bytes
• A MB, or megabyte, is 1024 kilobytes
• A GB, or gigabyte, is 1024 megabytes

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Memory

• RAM Read Only Memory
• This can also be referred to as direct memory
• Each storage position
• Has an unique address
• Can be individually accessed in the same amount
  of time without having to search through other
  storage positions
• Is used for data that needs to be retrieved
  quickly
• Is used during the running of applications
• Storage capacity is expressed in MB (megabytes)

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Memory

• Primary storage (main memory) of a computer
  consists of semiconductor memory chips
• Semiconductor memory has a small size, great
  speed, and shock and temperature resistance
• Provides working storage for your applications
• One disadvantage is that is requires a constant
  supply of uninterrupted electrical power

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Memory

• RAM continued
• Usually machines today come with between 128 and
  256 MB of RAM
• RAM is an important factor in how fast your
  computer runs applications
• More RAM is needed for applications that need a
  lot of temporary storage, such a photo-processing
  applications, and 3D games
• RAM is volatile i.e. the contents are lost as
  soon as power to the memory is interrupted

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Memory

• ROM Read Only Memory
• This memory can only be read, not erased or
  overwritten
• Control instructions and low level programs can
  be burned into this memory during manufacture
• This is also known as firmware
• This memory is non-volatile i.e. it doesnt
  require power to keep the contents in memory

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Memory

• L2 Cache
• As discussed earlier, the processor has a small
  amount of storage right on the chip
• A Level 2 Cache is memory external to the
  processor, it is stored on a chip outside the
  processor
• Now manufacturers are starting to build L2 caches
  right on the chip

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Data Storage

• Need to backup contents of main memory so
  information is not lost when the power is shut
  off
• These devices and technologies are known as
  secondary storage
• Three common types are
• Magnetic disks
• Magnetic tape
• Optical disks

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Data Storage

• Magnetic disks
• Fast access and high storage capacity for a
  reasonable cost
• Magnetic disk drives contain metal disks that are
  coated on both sides with a iron oxide recording
  material
• These disks are mounted on a vertical shaft that
  rotates them at speeds of between 3600 7600 rpm

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Data Storage

• Magnetic disks continued
• Electromagnetic read/write heads are positioned
  on arms between the disks to read and write data
  in concentric circles
• Data is recorded as tiny magnetized spots to form
  binary digits that the computer can read
• Disks have billions of storage positions

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Data Storage

• Magnetic Disks continued
• Floppy disks
• Polyester film disks coated with iron oxide
• Rotates inside a plastic jacket
• Most common floppy disk is the 3 ½ inch disk than
  can hold 1.44 MB of data

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Data Storage

• Magnetic Disks continued
• Hard Disk
• Combine magnetic disks, access arms, and
  read/write heads in a sealed module
• This allows higher speeds, greater data recording
  densities, and closer tolerances
• Hard drives can usually store up to many
  gigabytes of data
• Hard drives are where the operating system and
  applications are permanently stored

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Data Storage

• Magnetic Disks continued
• RAID Redundant arrays of independent disks
• Replace large capacity mainframe disk drives
• Many interconnected microcomputer hard disk
  drives provide large capacities with high access
  speeds since data is accessed in parallel
• If one disk fails, data can be recovered from one
  of the others

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Data Storage

• Magnetic Tape
• Data is recorded on the iron oxide coating of the
  magnetic tape
• Can hold over 200 MB of data
• Most commonly used for backup storage and
  archival of data
• This is a low-cost technology that supplements
  magnetic disk storage

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Data Storage

• Optical Disks
• A laser records data by burning permanent
  microscopic pits in a spiral track
• Drives use a laser device to read the binary
  codes formed by the pits
• CD-ROM disks can hold up to 600 MB of data, which
  is equivalent to 400 1.44 MB floppies, or 300000
  double spaced pages of text

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Data Storage

• Optical Disks continued
• CD Burners can be used to record data on CD-R
  disks (can only record on once) and CD-RW disks
  (can be recorded on over and over)
• DVD Digital Video Disk
• DVDs can hold between 3 and 8.5 gigabytes of data
• DVDs are expected to eventually replace CDs and
  CD-ROMs because of their large storage capacity
  and excellent quality