TEST 2 STUDY GUIDE

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TEST 2 - STUDY GUIDE
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Chapter 4 The Components in the System Unit

• System Unit - Box like case that houses the
  components of the computer to process data
• Motherboard main circuit board in the system
  unit

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Data Representation

• Character Codes ASCII, EBCDIC, and Unicode
  (Unicode has enough bits to represent the worlds
  languages)
• Binary- number system that has 2 digits 0 1
• Bit single binary digit
• Byte 8 bits
• Kilobyte approximately 1 thousand bytes (1024
  bytes)
• Megabyte approximately 1 million bytes
• Gigabyte approximately 1 billion bytes

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Central Processing Unit

• CPU interprets and carries out the
  instructions. The CPU contains
• Control unit directs and coordinates the
  operations in the computer
• ALU (arithmetic logic unit) performs
  arithmetic, logic and comparison instructions
• Registers temporary storage locations in the
  CPU
• Microprocessor CPU on a single chip (Integrated
  Circuit)

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Machine Cycle or How does a computer run a
program?

• Fetch control unit fetches an instruction from
  primary memory
• Decode translate the instruction to determine
  what it says to do and set up commands to do it.
• Execute process of carrying out the commands
• Store (not in every machine cycle) writing a
  result to primary memory

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Comparison of common microprocessors

• Pentium 4 Latest Intel processor running at 1
  GHz and up used in IBM compatible PCs such as
  Dells
• Celeron low cost Intel Pentium III
• Duron AMD processor in competition with Pentium
  4 used in IBM compatible PCs such as Dells
• PowerPC Motorola and others made this family of
  processors Used in Apple Macintoshs

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Clock

• Synchronizes or controls the timing of computer
  operations
• Rated in
• Mhz million cycles per second
• Ghz Billion cycles per second
• Example
• 1.4Ghz Pentium IV operates at 1,400,000,000
  cycles every second

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Primary Memory

• Temporary storage place for data and instructions
• RAM volatile can be read and written to
• Installed on mother board usually with SIMMs or
  DIMMs
• ROM nonvolatile can only be read
• Volatile memory that loses its contents when
  power is turned off

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Cache Memory

• High speed memory that is between the CPU and
  Primary memory
• L1 built directly on the processor chip
• L2 not on the processor chip with the exception
  of L2 advanced transfer cache which is on the
  processor chip

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ROM

• Used at boot-up time
• Data and instructions are recorded permanently by
  the manufacturer

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Flash BIOS

• Nonvolatile ram or ROM
• Used to keep up-to-date the BIOS of your computer
  (BIOS is basic instructions at startup and other
  hardware functions)

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CMOS

• Stores configuration information about your
  computer
• Powered by a small battery

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Expansion slots

• Place on the motherboard where a circuit board
  can be inserted
• Common types
• Video card
• Modem card
• Network card
• Sound card

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Plug and Play

• Adding a card or new device to your computer and
  your operating system and hardware detect the
  addition and configure it properly so that your
  computer can now use it.

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Buses and Word Size

• Bus allows various devices within the system
  unit to communicate via wiresThe larger the bus
  size the more data can be transferred at the same
  time.
• Word size number of bits that the processor can
  process at one time

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Ports

• An interface to attach a device to the system
  unit
• Serial port- transmits data 1 bit at a time(ex.
  Mouse, keyboard)
• Parallel Port transmits data 1 byte at a time
  (ex. Printer)
• USB Universal Serial Bus high speed port that
  can connect multiple devices using a hub
• 1394 Very high speed port found on Macintosh
  computers to connect digital cameras and video
  cameras
• irDA wireless transmission of data using light

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Questions

• How are numbers stored? How are characters
  stored?
• Explain the 4 operations of the machine cycle.
• What unit is doing the fetching?
• What is fetched?
• Where is the information to be fetched?
• What happens to it after it is fetched?

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More Questions

• Know the differences between RAM and ROM
• What is the purpose of the system clock?
• How does bus size and word size affect the speed
  of a CPU?
• How are serial ports, Parallel ports and USB
  ports different?
• What are some processors available today?
• Be able to name 2-3 manufactures of processors
  and 2-3 manufactures of computers that use those
  processors

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Chapter 5 Input
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Input

• refers to the process of entering data, programs,
  commands, and user responses into memory.

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Data

• Refers to the raw facts, including numbers,
  letters, words, images and sounds, that the
  computer receives during the input operation and
  process to produce information.
• Data must be entered and stored in memory for
  processing to occur.

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Instructions

• Program
• User response
• Command

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Input Devices

• Keyboard
• QWERTY - A standard computer keyboard
• Mouse
• Small, palm-sized input device that is moved
  across a flat surface, such as a desktop, to
  control the movement of the pointer on a screen.
• Mechanical
• Optical

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Input Devices Continued

• Trackball
• Is a pointing device like a mouse only with the
  ball on the top of the device instead of the
  bottom.
• Touchpad
• Small, flat,rectangular pointing device that is
  sensitive to pressure and motion.

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Input Devices Continued

• Pointing Stick
• Pressure sensitive device shaped like a pencil
  eraser that is positioned between keys on a
  keyboard
• Light pen
• A handhelp device that can send or detect light
  while pointing at a monitor
• Touch screen
• A touch sensitive monitor
• Stylus
• Looks like a pen but uses pressure instead of ink
  to write

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Automating data entry with devices(source data
automation)

• Optical devices (use light)
• OMR optical marks
• OCR optical characters
• Bar codes optical codes
• Magnetic devices (MICR)

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OMR

• Optical Marks Recognition
• Input devices that often are used to process
  questionnaires or test answer sheets. Carefully
  placed marks on the form indicate response to
  questions that are read and interpreted by a
  computer program.

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OCR

• Optical Character Recognition
• Scanning device that read typewritten,
  computer-printed, and in some cases hand-printed
  characters from ordinary documents,
• compare the characters with a predefined shape
  stored in memory, and convert the character into
  the corresponding computer code.

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Bar Code

• A typical form of optical code consisting of
  verticals lines and space, found on
• UPC code - most grocery and retails items
  usually scanned to produce price and inventory
  information about the product.

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MICR

• Magnetic Ink Character Recognition
• Characters use a special ink that can be
  magnetized during processing.
• MICR is used almost exclusively by the banking
  industry for processing checks.

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Digital Camera

• Takes pictures and store the photographed images
  digitally.

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Scanner

• A light-sensing input device that reads printed
  text and graphics and then translates the results
  into a form the computer can use.

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Sound Input

• Sound usually are recorded with a microphone
  connected to the sound card or by directly
  connecting a sound device, such as electronic
  music keyboard, to the sound card.
• Sound editing software allows you to change the
  sound after it is recorded.

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Voice input

• Input that is voice.
• Speaker dependent or speaker independent software
• Discrete or continuous speech

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Video Digitizer

• Devise use to capture an individual frame from a
  video and save the still picture in a file.

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Name 4 types of input

• Data
• Programs
• Commands
• User responses

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What is the most common used input device ?

• The most common input device is the keyboard.

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Name at least five types of direct data entry
device.

• Keyboard, Mouse, voice input, sound input, video
  input

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More Questions

• How does a Mouse Work? Trackball? Touchpad?
• How does voice recognition work?
• What is the primary input device for a PalmPilot?
  (Stylus)

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Chapter 6 Output

• Text, graphics, video or audio

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Soft Copy - Display Devices

• Monitors
• CRT and Flat Panel
• Projectors
• Terminals

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CRT (cathode ray tube) - typical monitor seen in
the computer lab

• big and bulky compared to flat panel
• monochrome (foreground and background color)
• color (many different colors)

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Flat Panel

• LCD (Liquid Crystal Display)
• Type of flat panel display screen that has liquid
  crystal deposited between two sheet polarizing
  material.When an electric current passes between
  crossing wires, the liquid crystals are aligned
  so line cannot shine through, produce an image on
  the screen.
• Gas Plasma - large panels that substitute gas
  instead of liquid crystals

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Video Display Terminals

• Consists of a keyboard and a screen.
• They fall into three basic categories
• dumb terminals, intelligent terminals, and
  special-purpose terminals.

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Pixel (Picture Element)Dot Pitch Resolution

• Pixel -On screen, the dots that can be
  illuminated.
• Resolution - Measure of a screens image clarity
• depends on the number of individuals dots
  (pixels) displayed on the screen.
• Dot Pitch - distance between the pixels (smaller
  is better)

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Video Cards

• converts the digital computer signal to the
  analog monitor signal
• support different standards
• a normal standard for today is SVGA typically
  1-24 X 768 pixels with 16.7 million colors with a
  4MB memory
• an 8MB memory can support higher resolutions

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Hard Copy - Printers and Plotters
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Impact printers and non-impact printers

• Impact - Printers that transfer images onto paper
  by some type of printing mechanism striking the
  paper, ribbon, and character together.
• Nonimpact Printers
• Printing occurs without having a mechanism strike
  against a sheet of paper.

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How is printing done and classify each of the
following printers

• Dot matrix - Impact printer
• Has a print head consisting of a series of small
  tube containing pins that when pressed against a
  ribbon and paper, it prints small dots closely
  together to form a character.
• Ink Jet - Nonimpact Printer
• that forms characters by using a nozzle that
  shoots droplets of ink onto the page producing
  high-quality print and graphics.

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Printing Continued

• Laser - Nonimpact printer
• Converts data from the computer into a laser beam
  aimed at positively charged revolving drum. Each
  position on the drum touched by a beam becomes
  negatively charged and attracts toner which is
  transferred and fused to paper by heat and
  pressure to create the text or image.
• Band -Impact printer
• Uses a horizontal, rotating band and can print in
  the range of 600 to 2,000 lines per minute.

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Multifunction devices

• combination of color printer, scanner, copy
  machine and fax all-in-one

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Other types of output

• voice output and any type of sound - through
  speakers and headsets

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Questions

• Name and explain 2 types of output devices
  besides a printer and monitor
• Data projectors projects display screen image
  to a group.
• Facsimile ( Fax) Transmit and receives text and
  image documents over telephone lines.
• What factors affect the quality of a monitor (see
  pg 6.34)and questions 1 through 7 on pages 6.34
  and 6.35

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Excel - Questions

• Why are spreadsheets useful?
• Give an example of a the use of a spreadsheet?
• What is a cell?
• How are columns and rows identified in an Excel
  worksheet?
• Name 3 types of information that can be placed in
  a cell.

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Excel More Questions

• Given a sample worksheet be able to write in the
  proper values and formulas
• How can sums be easily calculated in Excel?
• What is the fill handle and what is it used for?
• Be able to use the fill handle.
• What is the difference between a workbook and a
  worksheet?

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Excel More Questions

• How can a chart be added to a sheet?
• Explain 2 ways to enter formulas.
• With what do all formulas begin?
• How may a column width be changed?
• How can you find the average of a range of
  numbers?
• Be able to do exercises similar to the
  assignments.

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Excel More Questions

• Why is freeze pane useful?
• What is the difference between relative and
  absolute cell referencing?
• Give an example of when each is used. Be able to
  use them in problems.
• Be sure to know how to write if formulas.
• How do you copy non-adjacent cells?