TEST 2 - STUDY GUIDE

Chapter 4 – The Components in the System

UnitSystem Unit - Box like case that houses the components of the computer to process data

Motherboard – main circuit board in the system unit

Data Representation

Character Codes – ASCII, EBCDIC, and Unicode (Unicode has enough bits to represent the world’s 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

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 CPUMicroprocessor – CPU on a single chip (Integrated Circuit)

Machine Cycle or How does a computer run a

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

Comparison of common microprocessors

Pentium 4 – Latest Intel processor running at 1 GHz and up – used in IBM compatible PC’s such as Dell’sCeleron – low cost Intel Pentium III Duron – AMD processor in competition with Pentium 4 – used in IBM compatible PC’s such as Dell’sPowerPC – Motorola and others made this family of processors – Used in Apple Macintosh’s

Clock

Synchronizes or controls the timing of computer operationsRated in:Mhz – million cycles per secondGhz – Billion cycles per second

Example:1.4Ghz Pentium IV – operates at

1,400,000,000 cycles every second

Primary Memory

Temporary storage place for data and instructions

RAM – volatile – can be read and written to Installed on mother board usually with SIMM’s or

DIMM’s

ROM – nonvolatile – can only be read

Volatile – memory that loses its contents when power is turned off

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

ROM

Used at boot-up time

Data and instructions are recorded permanently by the manufacturer

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)

CMOS

Stores configuration information about your computer

Powered by a small battery

Expansion slots

Place on the motherboard where a circuit board can be inserted

Common typesVideo cardModem cardNetwork cardSound card

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.

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

PortsAn interface to attach a device to the system unitSerial 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 hub1394 – Very high speed port found on Macintosh computers to connect digital cameras and video camerasirDA – wireless transmission of data using light

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?

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

Chapter 5: Input

Input

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

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.

Instructions

Program

User response

Command

Input Devices

KeyboardQWERTY - 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.

MechanicalOptical

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.

TouchpadSmall, flat,rectangular pointing device that

is sensitive to pressure and motion.

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

Automating data entry with devices

(source data automation)

Optical devices (use light)OMR – optical marksOCR – optical charactersBar codes – optical codes

Magnetic devices (MICR)

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.

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.

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.

MICR

Magnetic Ink Character RecognitionCharacters use a special ink that can be

magnetized during processing.MICR is used almost exclusively by the

banking industry for processing checks.

Digital Camera

Takes pictures and store the photographed images digitally.

Scanner

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

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.

Voice input

Input that is voice.

Speaker dependent or speaker independent software

Discrete or continuous speech

Video Digitizer

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

Name 4 types of input :

DataProgramsCommandsUser responses

What is the most common used input

device ?The most common input device is the

keyboard.

Name at least five types of direct data

entry device.

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

More Questions

How does a Mouse Work? Trackball? Touchpad?

How does voice recognition work?

What is the primary input device for a PalmPilot? (Stylus)

Chapter 6 Output

Text, graphics, video or audio

Soft Copy - Display Devices

MonitorsCRT and Flat Panel

Projectors

Terminals

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)

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

Video Display Terminals

Consists of a keyboard and a screen. They fall into three basic categoriesdumb terminals, intelligent terminals,

and special-purpose terminals.

Pixel (Picture Element)Dot Pitch &

ResolutionPixel -On screen, the dots that can be

illuminated.Resolution - Measure of a screen’s image

claritydepends on the number of individuals dots

(pixels) displayed on the screen. Dot Pitch - distance between the pixels (smaller

is better)

Video Cards

converts the digital computer signal to the analog monitor signal

support different standardsa 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

Hard Copy - Printers and Plotters

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 PrintersPrinting occurs without having a mechanism

strike against a sheet of paper.

How is printing done and classify each of the

following printersDot 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.

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 printerUses a horizontal, rotating band and can print

in the range of 600 to 2,000 lines per minute.

Multifunction devices

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

Other types of output

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

QuestionsName 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

Excel - QuestionsWhy 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.

Excel More QuestionsGiven 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?

Excel More QuestionsHow 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.

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?