A. Computer A. Computer BasicsBasics

A. Computer A. Computer BasicsBasics

Unit Objectives:Unit Objectives:

1.01-1.041.01-1.04

1.00 Examine the role of hardware and software.

What Is A Computer?• An electronic device that receives data (input),

processes data, stores data (memory), and produces a result (output).

• Uses a binary system- - Combining bits (0 and 1), you can represent any character or number. The binary system plays a crucial role in computer science and technology. 

Benefits of Using Computers

• Error-free calculations• Speed• Flexibility• Storage• Consistency and repetition

What Is AComputer System?

• Hardware: the tangible, physical equipment that can be seen and touched such as:– Computer Case– Monitor– Keyboard and Mouse– Disk Drive– Speakers

• Software: the intangible set of instructions that tells the computer what to do; known as programs or software programs.– Two types: application and

system software programs• Data: information entered

into the computer to be processed, which consists of the following:– Text, numbers, sounds, and

images• People: the users of the

computers who enter the data and use the output.

Types of Computers• Supercomputer: most powerful

– Used to do things like predict hurricanes and navigate satellites

• Mainframes and minicomputers: used by business and government to process large amounts of information

• Personal computers: smaller and less powerful than the other types of computers

Personal Computers• Desktop computer: designed to be used

on a desktop.• Notebook/Tablet computer: designed

to be used on a desktop but still small enough to be portable.

• Laptop computer: designed to be small enough and light enough to be used on your lap.

Additional Typesof Computers

• PDAs (Personal Digital Assistants): a handheld device that is often used in conjunction with a desktop or other PC.– May have a special keyboard, some use a pen or stylus for entering data- Data can be transferred to a desktop or laptop computer

• Web TV: provides easy access to the Internet without having to have a traditional computer.– Enables you to connect to the Internet and usually

includes a keyboard or other device for entering and selecting data.

Data Communications• The technology that enables computers to

communicate• The transmission of text, numeric, voice or video data

from one machine to another.• Popular examples:

– Internet, electronic messages (e-mail), faxes, and electronic or online banking

• Four components:– Sender: the computer that is sending the message.– Receiver: the computer receiving the message.– Channel: the media that carries or transports the

message. (telephone wire, coaxial cable, microwave signal, or fiber optic)

– Protocol: the rules that govern the orderly transfer of the data sent.

Data Communications• Network: when computers are connected to

other computers– They can share information and sometimes

hardware (printers)– Local Area Networks (LAN): computers connected

together in a relatively close location such as in the same building or department.

• The data and software for these computers are stored on a central computer called the file server.

– Wide Area Networks (WAN): when local area networks are expanded to include several local area networks within a city, state, region, territory, country, continent, or the world.

System Components• Central Processing Unit (CPU): the microprocessor, the brains

of the computer.– Housed on a tiny silicon chip– Chip contains millions of switches and pathways that help your

computer make important decisions.• CPU knows which switches to turn on and which to turn off because it

receives its instructions from computer programs (software).– CPU has two primary sections:

• Arithmetic/logic unit• Control unit

• Arithmetic/logic unit (ALU): performs arithmetic computations and logical operations; by combining these two operations the ALU can execute complex tasks.– Arithmetic operations include addition, subtractions, multiplication,

and division.– Logical operations involve comparisons.

• Control Unit: is the “boss” and coordinates all of the CPU’s activities.

System ComponentsMemory: found on the motherboard; short term and long term.

– Random Access Memory (RAM): memory on the motherboard that is short term; where data, information, and program instructions are stored temporarily on a RAM chip or a set of RAM chips.

• When the computer is turned off or if there is loss of power, what ever is stored in RAM disappears.

• This memory known as the main memory and is considered volatile.• The computer can read from and write to RAM.

– Read-Only Memory (ROM): memory on the motherboard that is long term; where the specific instructions that are needed for the computer to operate are stored.

• This memory is nonvolatile and your computer can only read from a ROM chip.

• The instructions remain on the chip regardless if the power is turned on or off.

• Most common is the BIOS ROM; where the computer uses instructions contained on this chip to boot or start the system when you turn on your computer.

System Components• Basic Controllers: on the motherboard,

a device that controls the transfer of data from the computer to a peripheral device and vice versa.

• Examples: keyboards, mouse, monitors, and printers.

• Generally stored on one single chip.

• Serial and Parallel Ports: used to connect our peripheral devices to the computer; usually one serial and one parallel port on a computer.

• Serial devices transmit data one bit at a time.– A modem may be connected to this port.

• Parallel devices transfer several bits at a time.– A printer may be connected to this port.

System Components• Universal Serial Bus (USB): a new standard

that supports data transfer rates of up to 12 million bits per second.– A single USB port can be used to connect up to

127 peripheral devices– Expected to replace serial and parallel ports in

the near future.• Expansion Slots: an opening on the

motherboard where a circuit board or expansion board can be inserted.– Examples: Additional Memory, video cards,

modem cards, and sound cards.

How Does A Computer Process Data?

• PC system case – the metal and plastic case that houses the main system components of the computer.

• Central to all of this is the motherboard or system board that mounts into the case.– Motherboard: is a circuit board (a thin plate or

board that contains electronic components) that contains many integral components.

Data Representation

• ASCII (American Standard Code for Information Interchange): the most popular and widely used standardized coding system

• Byte: eight bits or combinations of ones and zeros represent a character.– MB-Megabyte or roughly 1 million bytes– GB-Gigabyte or roughly one billion bytes

Computer Input Devices

• Keyboard• Mouse/Trackball• Joystick• Light pen• Pointing Stick• Touchpad

• Touch screen• Bar code reader• Scanner• Microphone• Graphics Tablet• Digital Cameras

Input device: hardware that allows you to communicate with your computer.

Computer Output Devices

• Monitor: screen that display information such as text, numbers, and pictures.– Softcopy – output that is not

in printed form

• Printer: gives you information from the computer in printed form.– Hardcopy – a printed copy

of output

• Speakers: allow you to hear voice, music, and other sounds from your computer.

• Modem: allows you to use your computer to communicate with other computers.

•Output device: hardware that allows your computer to communicate with the user

Three Types of Printers

• Dot Matrix– Gives a printed image in

a pattern (matrix) of tiny ink dots.

• Less expensive and not as clear

• Inkjet Printer– Better quality of printed

document• Machine uses an ink

cartridge and a printing element to print a finer image on the paper.

• Laser– Best quality of

printed documents• Laser beam and an ink

toner cartridge are used to produce the images.

• More expensive• Quick

Storage Devices• Storage device: allows you to store or

retrieve information

Types of Storage Devices• Inside of Computer

– Hard Disk Drive - Magnetic storage devices use oxide-coated plastic storage media called mylar.

– As the disk rotates in the computer, an electromagnetic read/write head stores or retrieves data in circles called tracks.

• Tracks are numbered from the outside to the inside and as data is stored on the disk it is stored on one of these numbered track.

• Each track is labeled and the location is stored in a log on the disk known as a file allocation table (FAT). Benefits:

• Accessing data is faster• Amount of data that can be stored is much more than

what can be stored on a floppy disk.• Size of Hard drive is measured in megabytes or gigabytes.

Types of Storage Devices

• Mobile Storage Devices• Floppy Disk: flat circles of iron oxide-coated

plastic enclosed in a hard plastic case.• CD-ROM & DVD – optical disk that uses laser

technology to read and write data on silver platters.

• Flash Drives (Jump Drives) – USB connector • Zip Disk: capable of storing tremendous

amounts of information

Types of Storage Devices• Magnetic Tape Drives: used for making

backup copies of large volumes of data.– Very slow– Can be used to replace data that may have

been lost on the hard drive– look similar to audio tapes.– Holds more than Floppy

Systems Software• A group of programs that coordinate and control the

resources and operations of a computer system.– Enables all components of the computer system to communicate.

• Operating System (OS): provide an interface between the user or application program and the computer hardware.– Win 95/98/2000– Mac System 6/7

• Utility programs: help you perform housekeeping chores; complete specialized tasks related to managing the computer’s resources, file management, and so on.

• GUI (graphical user interface): graphical symbols (icons) represent files, disks,

• programs, and other objects.

Application Software

• Word Processing– program that allows you

to create, edit, and print text documents

• Report, flyer, memo

• Spreadsheet– Numbered Rows and

Lettered Columns– Intersection of them =

cell• Grade book, financial

info

• Database– Lets you set up an

electronic filing systems

– Enter text and numbers

• Find, search, and print info in different ways

– Address book, Card Catalog

Programs that work with the OS software to help you use your computer to do specific types of work

Business Software

Application Software• Communications

– Works with your modems or network hardware and allows your computer to communicate with other computers.

• Exchange computer files and email

• Graphics Software– Uses pictures or images

to help communicate messages.

• Multimedia: combines text, graphics, animation, video, and audio.– Example: Powerpoint

• Clip art: graphical images to be added to documents

• Desktop Publishing: uses both pictures and words to give you the ability to create documents– Newsletters and brochures

Application Software

• Education & Reference– Available on many

topics– Help– Easier– Quicker

• Examples: AR, Encyclopedia, etc.

• Entertainment & Leisure– Fun– Games and

simulations– Tests your skills– interactive

Application Software• Integrated

Software -Combine several software applications into one program.– Include:– Word Processing– Spreadsheet– Database– Communication

• Examples:– MS OFFICE– Lotus SmartSuite

Proper Computer Care• Keep food and drinks away from the computer

and keyboard.• Avoid dusty locations.• Use a surge protector.• Keep magnets Away.• Do not block vents on the CPU.• Avoid bright sunny locations.• Do not move the computer while it is in use.• Always exit programs properly.• Use a virus check program on a regular basis.

Proper Diskette Care• Do not remove from drives while drive in

running or light is on.• Avoid contact with magnets and

electromagnetic fields.• Keep disks stored in a clean, cool and dry

place with a protective cover.• Keep protective metal slider in place.• Use a virus check program on a regular basis.• Avoid hot and cold locations.• Make a back-up copy of your programs and

files.

Proper CD ROM Care• Keep CDs stored in a clean, cool and dry place

with a protective cover.• Avoid touching the back side of the CD; to

avoid scratches.• Avoid hot and cold locations.• Make a back-up copy of your programs and

files.• Insert into CD ROM Drive properly; label facing

up.• Only write on CD’s with a CD Marking Pen on a

label or the correct side of the CD.

Proper Care of Printers• Avoid cold, hot, and dusty locations.• Always use the correct ink or toner

replacement.• Always have the proper printer cable

connected to your computer.• Never pull paper out of a printer in motion.• Do not turn off the printer while printing.• Read the instruction manual before operating

a printer.• Always use the proper type of paper in your

printer.

How to Maintain your Computer System

• Start a notebook of information on your system.– Serial numbers– Vendor support telephone numbers– User IDs– Date and vendor for each equipment and software purchase.– Trouble log

• Periodically review disk directories and delete unneeded files.• Make sure all plug-ins are secure at all times.• Turn off the power and disconnect the equipment form the

power source before you open the inside of you computer.• Keep surrounding area dirt and dust free.• Back up files and data regularly.• Periodically defragment your hard disk.• Protect your system from computer viruses• Learn to use system diagnostic programs

Ergonomics• The science of designing equipment for a

comfortable and safe working environment.• Proper Computer Ergonomics

– Sit up straight and lean forward slightly from the waist.– Keep your feet flat on the floor.– Your body should be about a hand’s length from the front

of the keyboard and centered with the keyboard.– Keep your fingers on the home row keys and curved.– Keep your wrists up, not touching the keyboard or desk.– Focus your eyes on the book, copy or screen.– Place all materials you will type on the right side of the

computer and supplies on the left side.– Keep any items you are not using off your desk.– Occasionally rest your eyes and take short breaks.– Avoid lights that cause glare on the monitor.