Certificate in Accounting Lecture 05 Computer Operations and

Certificate in Accounting Lecture 05: Computer Operations and Data Retrieval

Objectives Retrieve, view and closed a Word Processing Create, save and print a word processed document Retrieve, view and closed a Spreadsheet Retrieve, view and closed a Graphic file Retrieve, view and closed a Database.

Topics Software Basics Operating systems Types of software Software Installation Copyright laws

Introduction Computers have become the most versatile machines man has ever created The reason is that software allows a computer to perform an infinite variety of tasks.

Computer Software When 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 result Example, Microsoft Word is called software, but the document file that you create is not software. That is data or a document file.

NOT EXAMINED Computer 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 only Thus, 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 like C++ into machine language so it can run on the computer

A running program The steps to run a program 1. 2. 3. 4. 5. 6. 7. Double click on a program to start Your clicking opens a compiled executable file stored on the hard drive The instructions (code of the program) is loaded into RAM and then sent to the CPU The CPU will run the program and ask the user to do something. When you are done with the program, you close it and the CPU stops executing the program The program instructions are erased from the RAM The CPU is ready for another program

Types of Software “Application” software 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 Systems The system software acts as the master controller for all that takes place on a computer Every type of computer has an operating system that defines many operations Examples: How many programs can run at once? What do the borders around programs look like? Can the computer connect to the internet?

OS The operating system will coordinate all activities that occur in a computer If, for example, you want to print a document, 1. Tell your application to print 2. The application tells the operating system that it wants to print 3. The OS talks to the printer device, and the document gets printed

OS and resources The 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 Memory One 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 OS Because 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 Buffer/Queue Program 1 1 st Program 2 Program 3 2 nd 3 rd

OS and GUI An 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

OS The operating system usually lives on the hard drive because it takes up a lot of space. NOT EXAMINED The 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 OS Single User – Only allows one person to use a computer at a time Multi-User – more than one person can execute programs on the computer Multi-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 Categories Multi-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 categories Server OS – this will run all the responsibilities of a server. It is most useful if it runs a network The 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 Systems Microsoft – DOS, Windows 3. 1, Windows 95, Windows 98, Windows 2000, Windows XP, Window Vista, Apple – Macintosh (latest called OSX) Linux – Redhat, Mandrake, Suse, Debian UNIX – Sun. OS

Application Software Applications let users accomplish tasks Word Processing - MSWord Spreadsheets - Excel Presentation – Power. Point Database - Access Desktop Publishing - Publisher Accounting, Mathematical, Statistics software Web authoring software

Data 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

Databases Database Management Software (DBMS) – this helps people sort through a lot of data. It is a piece of software like MS Access or my. SQL 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

DBMS So how do you use a DBMS? There are user interfaces that help The 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 Sione The SQL statement to do that would look like Select * from Student. Information where firstname=“Sione”

Other queries Some 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 Student. Information where name=“Sione”

Graphics Software Paint software – image editing (for fixing images) Photo editing software – can fix photos Drawing software – for making objects, boxes, lines 3 -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 Software To 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. MP 3 is a format of music. An MP 3 player can ‘decode’ the mp 3 format into one that you can hear. There are other formats like WAV, Ogg Vorbis, WMA

Software Installations To 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 Software 1. 2. 3. 4. 5. 6. Copy files from the disk (CD or floppy) Uncompress files (they are compressed to save space) Analyze computer to see if it meets system requirements Identify where operating systems files are that the program might need. For example: A MP 3 Player might need to know how to use the OS to send sound to the speakers Update system files like the windows registry. The program might need to tell the OS something about itself Move files into correct place

Uninstalling software To 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 Software Companies try very hard to stop people from stealing software. It is difficult because of a computer's ability to do many things Computers make it easy to copy and duplicate anything, including software, movies and music

Copyrights and Software Companies have tried aggressively to stop “software pirating” but fail. It is said the computer industry loses over 12 billion US dollars a year Piracy is very bad especially in India, China, and Eastern Europe where many people are too poor to buy software

Copyrights and Software Not all software costs money Shareware – lets you try software for a while, then asks you to pay for it to continue Freeware – the software is totally free

Copyrights and Software People 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 Source Open source is mainly associated with Linux and Unix, two types of operating systems The 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 Source Because 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 Problem Power Surges when something boosts the electrical charge at some point in the power lines which increase the electrical potential energy Courses Lightning High-power electrical devices Faulty wiring How Surge Protectors Work When to Use a Surge Protector

Environmental Problem How 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 Protector Surge protector depends on what sort of device being hooking up to power supply

Environmental Problem Blackout An accidental loss of electric power Effect – total cut out, - unexpected increases Avoid – using UPS – Uninterrupted Power Supply

Summary Operating systems Application Software Word Processor, Spreadsheet, Databases, Media players, Installing software Copyrights and Open Source Environmental Problems