Lecture 05:Computer Operations

and Data Retrieval

ObjectivesRetrieve, view and closed a Word ProcessingCreate, save and print a word processed

documentRetrieve, view and closed a SpreadsheetRetrieve, view and closed a Graphic fileRetrieve, view and closed a Database.

TopicsSoftware BasicsOperating systemsTypes of softwareSoftware InstallationCopyright laws

IntroductionComputers have become the most versatile

machines man has ever createdThe reason is that software allows a

computer to perform an infinite variety of tasks.

Computer SoftwareWhen computers first started, software was

defined as anything that was not hardware; anything that wasn’t real

The US government defines software:A set of instructions to be used in a computer to get a

certain resultExample, Microsoft Word is called software,

but the document file that you create is not software. That is data or a document file.

NOT EXAMINEDComputer Programs Programs are a set of detailed, step-by-step

instructions that tell a computer how to solve a problem or carry out a task

Programs are written in a computer language that the computer can understand.

Typical languages might be called C, C++, Java

Computer Programs [NOT EXAMINED]

Programming languages use different words and ideas to tell a computer what to do

Let’s look at what this program does

NOT EXAMINED How software works (more)A CPU understands a special machine

language onlyThus, when you write a program in C++,

Java, etc, it must be translated into this special machine language

A “compiler” will turn your programming code into machine language so it will run correctly

NOT EXAMINED How software works

Code is converted from a high level language likeC++ into machine language so it can run on the computer

A running programThe steps to run a program

1. Double click on a program to start2. Your clicking opens a compiled executable file stored on

the hard drive3. The instructions (code of the program) is loaded into

RAM and then sent to the CPU4. The CPU will run the program and ask the user to do

something.5. When you are done with the program, you close it and

the CPU stops executing the program6. The program instructions are erased from the RAM7. The CPU is ready for another program

Types of Software“Application” software are programs that the

user runs. These could be Microsoft Word, Excel, a video game, a DVD video player

“System Software” is the software that runs the operating system. It includes all the utilities and helper programs that run the operating system

Operating SystemsThe system software acts as the master

controller for all that takes place on a computerEvery type of computer has an operating

system that defines many operationsExamples: How many programs can run at

once? What do the borders around programs look like? Can the computer connect to the internet?

OSThe operating system will coordinate all

activities that occur in a computerIf, for example, you want to print a document,

1. Tell your application to print2. The application tells the operating system that it

wants to print3. The OS talks to the printer device, and the

document gets printed

OS and resourcesThe operating system manages system

resources. A resource might be the CPU, RAM, space on a hard drive

The OS must ensure all programs can get access to these resources when they need to.What if two programs both want to print?The OS will manage the resource, decide

who prints first and make the other program wait

The OS and MemoryOne of the most important jobs an OS has it to

manage memory (RAM). If more than one program is running, the two

programs are both using the RAM. How do we make sure that the programs don’t use

each other's memory??The operating system gives each program running

it’s own different “memory space.”Sometimes the OS makes mistakes (errors from

programmers) and programs will use memory from another program. The computer usually will crash when this happens!!

Internal OSBecause different programs might need the same

resource (memory, printer, speakers), the OS must decide when and how each gets its turn

It will use “buffers” and “queues” to accomplish this.

A buffer is like a line of things waiting to happen. The OS can finish with one, and then take the next in line

Program 1 Program 2 Program 3

Buffer/Queue

1st 2nd 3rd

OS and GUIAn OS will also usually determine the

“look and feel” of a computer. With the graphical user interface (GUI) the

OS can change how menus, windows and icons appear to the person using the computer

GUI and Text interface. OS changes the way it looks

OSThe operating system usually lives on the hard

drive because it takes up a lot of space. NOT EXAMINEDThe most important part of the OS is the

“kernel.” The kernel accomplishes the most important tasks, like managing files and using memory.

You can’t close or exit the kernel. It is always running. It’s what makes your computer and operating system run.

Types of OSSingle User – Only allows one person to use a

computer at a timeMulti-User – more than one person can execute

programs on the computerMulti-User don't mean many people can use the

same keyboard and monitor at the same time, but instead there are ways, by using the network, to run programs on the computer

More OS CategoriesMulti-tasking – this means the OS can run more

than one program at a time. All current Operating Systems are multi-tasking and allow you to do more than one thing at once.

If you talk on a cell phone and drive at the same time, you are multi-tasking (doing more than one thing at a time). A computer is very good at this

More OS categoriesServer OS – this will run all the responsibilities

of a server. It is most useful if it runs a networkThe main difference between a server and a

regular computer is that a server runs certain programs (called services) that provide things for the client.

Any computer can be turned into a server with the proper programs.

Desktop OS – used on client or desktop machines.

Available Operating SystemsMicrosoft – DOS, Windows 3.1,Windows95,

Windows98, Windows 2000, Windows XP, Window Vista,

Apple – Macintosh (latest called OSX)Linux – Redhat, Mandrake, Suse, DebianUNIX – SunOS

Application SoftwareApplications let users accomplish tasksWord Processing - MSWordSpreadsheets - ExcelPresentation – PowerPointDatabase - AccessDesktop Publishing - PublisherAccounting, Mathematical, Statistics

softwareWeb authoring software

Data management softwareData management software (databases) help

organize, sort, store, and update data.A “record” holds the data for a single entity.

If we had a database for students, a single “record” would save all the information about one student

A “field” holds one item of data. The students name would be a field. So would his age,

or address

DatabasesDatabase Management Software (DBMS) – this

helps people sort through a lot of data. It is a piece of software like MS Access or mySQL

Most powerful DBMS use what is called a “relational” database structure.

“Relational” means that relationships can be found and created between different sets of data.For example, you might have a set of data about

students and one about classes.If the class table saved who was in the class, you

could look up and see where that student lived, using the student table. This is a relationship

DBMSSo how do you use a DBMS?There are user interfaces that helpThe main way is through a programming

language called SQL (Structured query language). A query is a question.

Example: You could “query” a database of students to find all students with the name SioneThe SQL statement to do that would look likeSelect * from StudentInformation where

firstname=“Sione”

Other queriesSome advanced databases use Natural Language

Queries.This means you could just enter:

What students are named Sione?This would work the same as the SQL query

select * from StudentInformation where name=“Sione”

Graphics SoftwarePaint software – image editing (for fixing

images)Photo editing software – can fix photosDrawing software – for making objects, boxes,

lines3-D graphics CAD software (Computer Aided Design) – used

by people who make buildings, cars, anything that needs to be designed before it is built.

CAD software can make blueprints for designs

Music SoftwareTo hear music on your computer, you need a

music player (like windows media player or winamp).

These players can “decode” a specific format of music into the kind needed for it to come out of speakers.

MP3 is a format of music. An MP3 player can ‘decode’ the mp3 format into one that you can hear.

There are other formats like WAV, Ogg Vorbis, WMA

Software InstallationsTo install software

you will need the “distribution disks” - either CDs or floppies.

Also you need to make sure your computer has enough memory and is fast enough to run the software

This is called “system requirements”

Steps in Installing Software1. Copy files from the disk (CD or floppy)2. Uncompress files (they are compressed to save space)3. Analyze computer to see if it meets system

requirements4. Identify where operating systems files are that the

program might need. For example: A MP3 Player might need to know how

to use the OS to send sound to the speakers5. Update system files like the windows registry. The

program might need to tell the OS something about itself

6. Move files into correct place

Uninstalling softwareTo get rid of software that you don’t want

anymore first look for a uninstaller program that came with the installation of the program.

If there is not an uninstaller, go to the control panels (on windows) and look for the icon that says, Add/Remove Programs.

If you just try to delete a program, there may be many parts that are left over from the program that will take up space if not removed

Uninstalling

Copyrights and SoftwareCompanies try very hard to stop people from

stealing software.It is difficult because of a computer's ability

to do many thingsComputers make it easy to copy and

duplicate anything, including software, movies and music

Copyrights and SoftwareCompanies have tried aggressively to stop

“software pirating” but fail.It is said the computer industry loses over 12

billion US dollars a yearPiracy is very bad especially in India, China,

and Eastern Europe where many people are too poor to buy software

Copyrights and SoftwareNot all software costs moneyShareware – lets you try software for a while,

then asks you to pay for it to continueFreeware – the software is totally free

Copyrights and SoftwarePeople today are beginning to realize they do

not need to buy software and can use free software

This software is called “open-source” - because all the code that people made is available to see and change.

“Closed-source” is what companies like Microsoft use to hide their property so people cannot change and use it improperly

Open SourceOpen source is mainly associated with Linux

and Unix, two types of operating systemsThe Linux operating system and all the

programs that can be used with it are free and are open source

If a program is open source and you don’t like how it runs, you are free to change the code and make the program do something else

Open SourceBecause open source allows everyone to look

at the code or programming, people say it is more secure and more stable.

Many people all over the world can look at the software, instead of just a few people inside a company.

Environmental ProblemPower Surges

when something boosts the electrical charge at some point in the power lines which increase the electrical potential energy

CoursesLightningHigh-power electrical devicesFaulty wiring

How Surge Protectors WorkWhen to Use a Surge Protector

Environmental ProblemHow Surge Protectors Work

Protect electronic devices from surges.If the voltage from the outlet surges or spikes

-- rises above the accepted level -- the surge protector diverts the extra electricity into the outlet's grounding wire.

When to Use a Surge ProtectorSurge protector depends on what sort of

device being hooking up to power supply

Environmental ProblemBlackoutAn accidental loss of electric powerEffect – total cut out, - unexpected increasesAvoid – using UPS – Uninterrupted Power

Supply

SummaryOperating systemsApplication Software

Word Processor, Spreadsheet, Databases, Media players,

Installing softwareCopyrights and Open SourceEnvironmental Problems