Basic Computer

System Unit
A computer system unit contains many parts. 
Motherboard - The motherboard is the main circuit board of a microcomputer.  It is also known as the main board or system board.
CPU - The CPU is the central electronic chip that determines the processing power of the computer.
Memory - Memory is the part of the computer that temporarily stores applications, documents, and stem operating information.
Bus - A bus is an electronic line that allows 1s and 0s to move from one place to another.
Expansion Slots - Expansions slots appear on the motherboard.  They are sockets into which adapters are connected.
Ports and Connectors - A port is a connector located on the motherboard or on a separate adapter.
Bays - A bay is a space inside the computer case where a hard drive, floppy drive or CD-ROM drive sits
Power Supply - A power supply changes normal household electricity into electricity that a computer can use.
Sound Components - A sound card lets a computer play and record high quality sound.

Central Processing Unit (CPU)
Does all of the work for the computer
    1. Does all of the mathematics, mainly addition
    2. Does all the logical comparisons of values
    3. Directs the flow of data in a computer
    4. Controls the operation of the parts of the computer
Today, all CPUs are microprocessors
    1. A microprocessor is a complete computer on a silicon chip  
    2. A microprocessor does all of the functions of a computer
      • stores data and instructions waiting to be used
      • follows changeable instructions
      • does input, processing, and output


 CPUs have three basic parts
    1. The Arithmetic Logic Unit (ALU)
      • does all of the mathematics in a computer
      • does all of the logic comparisons of values
      • some common logic comparison symbols
        • = equal to
        • < less than
        • > greater than
        • <= less than or equal to
        • >= greater than or equal to
        • <> not equal
    2. The Control Unit
      • directs the flow of information into the CPU and/or memory or storage
      • controls which instructions the CPU will do next
    3. Registers
      • Used to store data and instructions inside the processor
      • Size of the registers can affect the speed and performance of the processor
Speed of CPUs
    1. The speed of CPUs is measured in hertz.
      • A hertz is on cycle per second.
      • Need to measure time to determine cycles per second
        • All computers have a clock built into them for timing the cycles
        • The clock is usually located in a small metal box on the motherboard.
      • Today, many CPUs can complete over six (6) instructions per second.
    2. Speeds of modern CPUs
      • Most computers have a CPU that can do more than 400 MHz.
        • MHz stands for megahertz
        • A MHz is 1,000,000 cycles per second.
      • Computers will soon be at speeds of over a gigahertz, 1,000,000,000 Hertz.

Memory
Primary memory can be used directly by the CPU
  1. Consists of silicon chips, usually either VLS or VLSI technology is used to create the chips
  2. Two forms of Primary Memory
    • Read Only Memory (ROM)
    • Random Access Memory (RAM)
  3. Primary memory is also called primary storage
Read Only Memory (ROM)
  1. Stores instructions that are used by the CPU
    • Tells the CPU how to be the kind of computer it is, for example a Windows, Macintosh, or Play Station computers.
    • Tells the CPU how to work with the different parts of the computer
    • ROM can also hold programs that are directly accessed by the CPU.  One such program is the self-test when the computer is first turned on.  The self-test tests to seem if all the parts on the main circuit board (mother board) are working correctly.
  2. The instructions in ROM can not usually be changed
    • The instructions are built into the electronic circuits of the chips
    • These instructions in ROM are called firmware
    • To change the instructions in ROM you need to usually change the chips or do some other special process that is normally not available to an average user.
  3. The instructions in ROM are nonvolatile.  They stay in ROM even when the computer is turned off.
  4. Access to information is random access.
    • Random access means that any piece of information in ROM can be accessed at any given time without access other information first.  It is a lot like the tracks on a music CD.  You can access any track at any time and in any order.
    • The other kind of access is sequential access.  You must access the information in the order that they are located.  This is a lot like a music tape.  You must play the songs in order, or you have to fast forward past songs to get to the one you want.
Random Access Memory (RAM)
  1. Store data and instructions that are used by the CPU to perform some task.
    • These instructions are usually loaded into RAM from a secondary storage device.
    • RAM is also used to store instructions that tell the CPU how to work with its parts.  These instructions are usually called drivers.
  2. The instructions in RAM are constantly changing, depending on the needs of the CPU.
  3. The instructions in RAM are volatile.
    • When the computer is turned off the information in RAM disappears.
    • The information in RAM needs to be saved to secondary storage before the computer is turned off.
  4. Access to information is random access.                                        Storage Devices
How a computer stores information
    1. The computer stores information as a string of zeros (0) and ones (1)
      • The standard string length is eight 0's or 1's in a row
      • This standard length is called a byte
      • A byte equals one character
        • A character is a letter, number, or symbol - it is about any thing that can be typed on a keyboard
        • There are 256 standard characters used by almost all computers
    2. Information size measurements
      • Kilobyte (KB)
        • One kilobyte equals about 1024 bytes
        • 1KB is about 140 words, about a half page of typed double-spaced text (words only)
      • Megabyte (MB)
        • One megabyte equals about 1000 KB
        • One megabyte equals about 1,000,000 bytes
        • One megabyte equals about 500 pages of text, or one large book
      • Gigabyte (GB)
        • One gigabyte equals about 1000 MB
        • One gigabyte equals about 1,000,000 KB
        • One gigabyte equals about 1,000,000,000 bytes
        • One gigabyte equals over 1,000 books of text
Some Common Storage Devices
Hard Drive
The hard drive is the primary device that a computer uses to store information.  The hard drive stores programs, data files, saves files, and organizes files.  The hard drive is located inside the computer case.  The hard drive, magnetically stores data on stacks of rotating disks called platters.
                   
Floppy Drive
The floppy drive stores and retrieves information on a floppy disk
CD-ROM is a device that reads information stored on a compact disc.  CD-ROM stands for Compact Disc Read Only Memory.  One CD is equal 700mb. DVD-ROM stands for Digital Versatile Disc or Digital Video Disc Read Only Memory.
                 
Removable Hard Drive
A zip disk is a removable disk that holds a large amount of information. A zip disk can be used to achieve, protect and transfer large amounts of data.
A flash drive is a small storage device that can be used to transport files from one computer to another. They are slightly larger than a stick of gum, yet many of these devices can carry all your homework for an entire year! You can keep one on a key chain, carry it around your neck, or attach it to your book bag.
                           
 Communications Devices
Specific equipment and programs are needed to connect to the Internet or to communicate with other computers.  You can use any type of computer such as IBM compatible or Macintosh to connect to the Internet or communicate with other computers.  You need special programs to use the Internet.  Most companies that connect you to the Internet provide the programs you need free of charge.  You also need a modem to connect to the Internet.  A modem translates computer information into a form that can be transmitted over telephone lines.  Modems can be used to connect you to the Internet, exchange information, and to send and receive faxes.

Peripheral Devices

A peripheral device is any piece of hardware attached to a computer. A few examples of peripheral devices are printers, scanners, and digital cameras. 
Software
Software -- General Information

Computer software provides instruction that tell the computer how to operate.
    1. Software is also called programs.
    2. Programs are usually created using other software called programming languages.
There are two (2) main types of software
  1. System Software
    • Used by the computer to accomplish a task.
    • What system software does:
      • controls the internal function of the computer
      • controls other devices connected to the CPU
  2. Application Software
    • Used by people to accomplish a specific task.
    • Some common kinds of application software
      • Word Processor software
      • Database software
      • Spreadsheet software
      • Games
      • Web Page Browsers
Kinds of Software
  1. Public Domain Software
    • Has no copyright - no one owns the right to control who can make copies of the software.
    • Free to use or make copies of.
    • Can be copied, used in other programs, or changed by anyone.
  2. Freeware
    • Has a copyright - someone owns the right to determine who can make copies of the software.
    • Free to use and make copies of.
    • Can only give away exact copies of the software.
    • Can not be changed or used in another program without the copyright holder's permission.
  3. Shareware
    • Has a copyright.
    • Allowed to use the software before paying for it.
      • Can be a demo - which limits some major features like the Save command.
      • Can set an amount of time you can use the software.
      • Can trust that you will pay for it if you like the software.
    • Can only give away exact copies of the software.
    • Can not be changed or used in another program without the copyright holder's permission.
  4. Commercial Software
    • Has the most resistive copyright.
    • Have to buy the software before you can use it.
    • Can usually make one copy of the software as a backup copy.
      • A backup copy is used in case something goes wrong with the original software.
      • Can not give away or sell the backup copy.
    • Cannot copy, look at the program's code, change, or use the software in another program without the copyright holder's permission.
    • Commercial Software is the best software in the world.
How Software is Inputted into Computer
  1. Built into the computer's circuits, the ROM chips.
  2. Loaded into the computer from a secondary storage device, like a floppy disk or hard disk drive.
  3. Typed in from the keyboard.
    • Usually need to use a programming language to create the software.
    • Rarely done by most computer users today
System Software
System software is a type of program that acts like a conductor in an orchestra.  It directs all the activities and sets all the rules for how the hardware and software work together. MS DOS and Microsoft Windows are examples of system software or operating system software.

Some System Software is built into the computer.
1.      ROM chips and BIOS.
2.      Helps to setup the computer and start it.
Operating Systems
1.      The operating system is usually located on a disk.
o    Can be on either the hard disk drive, a floppy disk, or CD-ROM disk.
o    Must be loaded into RAM before it can be used.
2.      Used by the computer's hardware to work with its parts.
o    Tells the computer how to:
§  display information on the screen.
§  use a printer.
§  store information on a secondary storage device.
o    The system software that controls peripherals are called drivers.
3.      An operating system works with application software.
o    Does basic tasks, like printing a document or saving a file
o    The operating system starts (launches) the application software so that it can be used.
User Interfaces
1.      The user interface is how the computer's operating system presents information to the user and the user gives instructions (commands) to the computer.
2.      There are two kinds of User Interfaces
o    Text Interface
§  Presents information to the user in the form of text.
§  Have to type in commands or select commands from a menu displayed as text on the screen.
§  Hard to use or learn, because the user must memorize and type in commands.
§  Examples:
§  MS-Dos (MicroSoft Disk Operating System)
§  ProDos (Professional Disk Operating System)
§  Many of the Text Interfaces had shells placed over them.
§  A shell was more of a Graphic User Interface.
§  Made using the Text Interface easier to use.
o    Graphic User Interface (GUI)
§  Presents information to the use in the form of pull-down menus and icons.
§  Pull-down menus the user clicks on to display the menu
§  Icons are small pictures that stand for something, like a file, volume, trash, or program
§  The user gives commands to the computer by selecting items from a menu or by clicking on an icon when using a pointing device.
§  GUIs are easy to learn and use
Application Software
Application software programs work with the operating system software to help you use your computer to do specific types of work such as word processing to type a letter.
    1. Used by people to solve general problems
      • Can be used to do more than one thing - adapted to a wide variety of tasks
      • Some common tasks done by general purpose application software
        • Planning
        • Writing
        • Record keeping
        • Calculating
        • Communicating
        • Drawing
        • Painting
      • What can be done with general purpose application software is only limited by the imagination of the user.
    2. Examples of general purpose application software
      • Word Processing Software 
      • Database Software
      • Spreadsheet Software
      • Desktop Publishing Software 
      • Paint and Draw Software 
                
Utilities
Utilities allow you to complete certain tasks on your computer. Examples of some of these tasks are file organizations.
  • Specific purpose application software used to help a computer work better or to avoid problems.
  • Some utility programs are built into the operating system
    • Scandisk in the Windows operating system
    • Disk formatting software
  • Examples of utility programs
    • Anti-virus software
    • Disk maintenance software 
  • File management programs
  • Security software                                                                                                 Maintaining Your Computer
General Dos and Don't
Do:
  • Always shut down your computer properly.
  • Do regular Scandisk to check the hard disk surface for damage.
  • Defragment the hard drive periodically.
  • Delete all files and programs you no longer need from your computer.
  • Use a anti-virus program to prevent a virus on you computer.
  • Back up data to floppy disks or zip disks to ensure you have a copy.
Don't:
  • Do not eat around the computer.
  • Do not drink around the computer.
  • Do not use magnets around a computer.

Taking Care of disks
Do:
  • Delete all files you no longer need from your disk.
  • Use a anti virus program to scan for viruses on a disk.
  • Do prevent erasing and recording information on a disk by write-protecting it.
Don't :
  • Do not use magnets around a disk.
  • Do not take a disk apart.
  • Do not remove the disk while it is in use.
  • Do not store in extremely hot or cold locations.
  • Do not spill liquids on the disk
Cleaning Hardware
Follow instructions in the manual or in help files that came with the computer or other hardware devices.
Before cleaning anything, unplug it from the electrical wall socket.
When to clean a computer
1.      Computers do not need to be cleaned too often if they are kept in a clean environment
2.      Clean the computer when it looks dirty or when a device (like a mouse) does not work right.
3.      The two things that need the most cleaning are the screen and mouse.
Materials needed for cleaning a computer
    1. Most cleaning materials can be found in a home or any store
      • soft lint-free cloths
      • soapy water - a drop or two of dishwashing detergent in a gallon of water
      • cotton swabs
      • eraser
      • water spray bottle to hold the soapy water
      • used fabric softener cloth
    2. You may have to buy the following at a computer or office supply store
      • floppy disk drive cleaner kit 
      • CD-ROM drive cleaner kit
      • compressed air
Cleaning the case and other plastic surfaces
    1. Use a damp lint-free cloth to clean the case
      • Spray the water on the cloth. NEVER SPRAY WATER ON A COMPUTER OR OTHER ELECTRICAL DEVICES!
      • Wipe the surfaces with the damp cloth.
    2. For more difficult marks use the eraser.  An ink eraser works best.
    3. For cracks and tight places, use a slightly damp cotton swab.
Cleaning a monitor's screen
    1. Wipe the screen with the damp lint-free cloth
    2. Use a dry cloth to dry the screen
    3. You may want to use a used fabric softener cloth to help remove static charges on the screen
      • static charges attract dust to the screen
      • a fabric softener cloth has anti-static chemicals on it
      • wipe the screen very lightly with the used fabric softener cloth
      • Do not use a fresh fabric softener cloth.  It will leave streaks.
Cleaning the keyboard
    1. Use a slightly damp cotton swab to clean in-between the keys
    2. Wipe the outside of the keyboard with a damp cloth
    3. Use compressed air to remove paper pieces and dust from under the keys
    4. Do not take a keyboard apart to clean it!  You may not get it back together again.
Cleaning a mouse
    1. Clean the outside of the mouse with a damp cloth
    2. To clean the inside of the mouse
      • Take the mouse apart
        • turn the mouse upside down
        • rotate the retaining ring until it comes free
        • turn the mouse right-side up and catch the ring and ball in your hand
      • Use damp cotton swabs to clean the rollers inside the mouse.  Be sure to rotate the rollers to get all of the dirt off of them.
      • Wash the ball in warm soapy water.  Wipe dry with a lint-free cloth
      • Blow out the inside of the mouse to remove any dust
      • Put the mouse back together after it has drie
Inside the computer's case
    1. The inside of the computer rarely has to be cleaned and it is not recommended that this be done
    2. If you must clean inside your computer follow the following precautions
      • Be very careful. You can easily damage the computer or hurt yourself.
      • Do not touch the chips or other electrical components
      • Use a vacuum cleaner to remove dust carefully
      • Use compressed air or the blower option on a vacuum cleaner to blow out dust and other particles
Floppy disk drives and other drives with removable media
    1. Follow the instructions on the cleaning kit.
    2. Do not clean your drives too often, especially the floppy disk drive.  The cleaning disk is slightly abrasive and can wear down the drivers read/write heads.
         Security, Privacy, and Ethics

Security
Computers can store both public and private data. You ensure that what is stored on your computer is secure you can use a password to protect the material. User names and passwords can also protect the information stored on a computer. When using the Internet, one should use caution when giving out personal information.
Information Privacy
Intellectual property is a product someone creates based upon his or her thoughts or ideas.  Copyright laws exits to protect those who create an idea or product.  When using computers, one must  respect the property, rights, and privacy of others.
One of the problems related to privacy is the tendency to regard anything displayed on a computer screen as public information. Although most people, including students, would never pick up and read a document lying on someone else's desk, many people do not hesitate to read someone else's computer screen. As word-processing and other tool software becomes more and more common, we must extend the courtesy of privacy from written documents to material displayed on computer screens or stored on disks.

Ethics and the Information Age
Ethics are the standards of honest, morality, and fairness.  These standards relate to using computers. One has a responsibility to respect the property, rights, and privacy of others in the way you use computers.  Today in the Information Age, one must follow a code of ethics to respect others properties and others personal information.
The legal aspects of computing are complex and multilayered. Teachers can help society by practicing ethical computer use, avoiding software piracy, and providing direct instruction on ethical computing practices.
 Computer Applications in Education
Management

Computers are used in a variety of ways in the educational field.  Computers can be used in school management such as budget, inventory, student records, communications, library circulation, and library public access catalog.

Learning and Instruction

Computer applications can be used in education for learning and for instruction.  Instruction and learning can be divided into two major areas, teacher-centered instruction and student-centered learning.
Teacher-centered instruction examined the computer as the object of instruction as well as a tool of instruction and the management of instruction. It is subdivided into the categories of computer literacy, CAI, CMI, and design of teaching materials.
Student-centered learning views the computer as a tool for the student to use to create, access, retrieve, manipulate, and transmit information in order to solve a problem. Understanding the concept of the computer as an information tool relies on accepting the fact that the computer is a productivity tool for the student and the teacher alike.

Educational Research

Computers are used widely in educational research.  Educational research includes functions relating to information gathering and processing. The teacher/researcher may examine student performance data in new and revealing ways. Bibliographic citations of studies performed by educators around the world can be acquired and perused from the desktop computer.