INFORMATION TECHNOLOGY

GIVE YOUR UNDERSTANDING ABOUT THE PARTS OF A COMPUTER SYSTEM FOR UTILIZING IT FOR OFFICE AND GENERAL USE, EFFECTIVELY.

Following is my Understanding of various parts of a Computer System for utilizing it for Office and General Use :

1. Input Devices

An input device lets you communicate with a computer. You can use input devices to enter information and issue commands. A keyboard, mouse, scanner, digital camera, touch pads and joystick are examples of input devices.

Some Common Computer Input Devices :

Keyboard

• Used to type data into the computer

• Most common input device today

• Has special keys for giving the computer commands

o Commands tell the computer to do something, like save the file

o These special keys are called command or function keys

Pointing Devices

• Pointing devices move some object on the screen and can do some action

• Common pointing devices

o Mouse - most common pointing device

o Track ball - basically an upside down mouse

o Joystick

o Game controller

Scanner

A scanner allows you to scan documents, pictures, or graphics and view them on the computer. You can also use software to edit the items you scan.

• Used to put printed pictures and text into a computer

• Converts an image into dots that the computer can understand

• To scan text, optical character recognition (OCR) software is needed

Digital Camera

• Used to take electronic pictures of an object

• The pictures taken by a digital camera can be used directly by a computer

Microphone

• Used to put sound into a computer

• Need sound recording software

CD-ROM/DVD-ROM

• Can be used to put both sound and images into a computer

• Use a laser to read a Compact Disk (CD) or a DVD disk

Video Capture Card

• Usually place inside the computer's case

• Use to put video into a computer

• Need a video source, either a video camera or video recorder

2. Output Devices

An output device displays information on a screen, creates printed copies or generates sound. A monitor, printer, and speakers are examples of output devices.

Some Common Output Devices:

Monitors and Displays

• Shows the processed information on a screen

o A monitor uses a Picture Tube like a television with the image displayed on the front of the tube, which is called the screen.

o Displays are flat and use plasma, LCD, active-matrix, or some other technology.

• Monitors used to be called Cathode Ray Tubes (CRTs) because of the picture tube, which is a large vacuum tube.

• A monitor or display produce a soft copy. When the device is turned off the information goes away.

• Monitors are slowly being replaced by flat panel displays.

Printers

• Printers produce a hard copy

• The information is printed on paper and can be used when the device is off.

• It is also called a printout

• Dot-matrix printers (impact printer)

o Uses metal pins to strike an inked ribbon to make dots on a piece of paper.

o Can see the dots that make up the letters or images.

o Lowest print quality of all of the printers.

o Very low in cost per page to use.

o Rarely used today because of the poor print quality, but still used in business to print multi-part forms.

• Ink jet printers (non-impact printer)

o Use drops of magnetic ink to produce dots on a page to produce text or images.

o The print quality is almost the same as a laser printer's.

o Problems with the ink

 The ink is very expensive

 The ink is water soluble and will run if the paper gets wet

o Highest cost per page of all the printers

o For producing color documents, it has the highest quality at a reasonable price.

• Laser printers (non-impact printer)

o How the laser printer produces an image

 A laser or LEDs make dots on a light sensitive drum

 Toner (very tiny particles of plastic) stick to the drum where the dots where made

 Paper is pressed against the drum and the toner is placed on the paper

 The paper is heated and the toner melts into the paper

o Produces the highest quality printout

o For black and white printouts, very low cost per page

o Printout is permanent

o Color laser printers are still fairly expensive .

Speakers

• used to output sound

3. 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 mainboard 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 hertzs.

 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 megahertzs

 A MHz is 1,000,000 cycles per second.

 Computers will soon be at speeds of over a gigahertz, 1,000,000,000 Hertzs.

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

o Read Only Memory (ROM)

o 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

o Tells the CPU how to be the kind of computer it is, for example a Windows, Macintosh, or Play Station computers.

o Tells the CPU how to work with the different parts of the computer

o 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

o The instructions are built into the electronic circuits of the chips

o These instructions in ROM are called firmware

o 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.

o 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.

o 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.

o These instructions are usually loaded into RAM from a secondary storage device.

o 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.

o When the computer is turned off the information in RAM disappears.

o The information in RAM needs to be saved to secondary storage before the computer is turned off.

4. Access to information is random access.

4 .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 Drive

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 to the space in over 40 floppy disc.

Removable Hard Disk

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.

5. 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.

6 . Peripheral Devices

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

7. Software

Software -- General Information

Computer software provides instruction that tell the computer how to operate.

1. Software are 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

o Used by the computer to accomplish a task.

o What system software does:

 controls the internal function of the computer

 controls other devices connected to the CPU

2. Application Software

o Used by people to accomplish a specific task.

o Some common kinds of application software

 Word Processor software

 Database software

 Spreadsheet software

 Games

 Web Page Browsers

Kinds of Software

1. Public Domain Software

o Has no copyright - no one owns the right to control who can make copies of the software.

o Free to use or make copies of.

o Can be copied, used in other programs, or changed by anyone.

2. Freeware

o Has a copyright - someone owns the right to determine who can make copies of the software.

o Free to use and make copies of.

o Can only give away exact copies of the software.

o Can not be changed or used in another program without the copyright holder's permission.

3. Shareware

o Has a copyright.

o 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.

o Can only give away exact copies of the software.

o Can not be changed or used in another program without the copyright holder's permission.

4. Commercial Software

o Has the most resistive copyright.

o Have to buy the software before you can use it.

o 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.

o Can not copy, look at the program's code, change, or use the software in another program without the copyright holder's permission.

o 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.

o Usually need to use a programming language to create the software.

o 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

 Examples:

 Windows 98

 Windows 2000

 MacOS

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

o Scandisk in the Windows operating system

o Disk formatting software

• Examples of utility programs

o Anti-virus software

o Disk maintenance software

• File management programs

• Security software

This is my Understanding of various parts of a Computer System and Softwares that can be used on it for utilizing it for Office and General Use.