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Computer Literacy BASICS2
Objectives
Distinguish between software and hardware. Explain how a computer software program
works. Understand the steps involved in software
development.
Describe the difference between applications software and systems software.
Computer Literacy BASICS3
Objectives (cont.)
Describe the three categories of systems programs.
Describe operating systems for microcomputers, including network operating systems.
Define a user interface.
Computer Literacy BASICS4
Objectives (cont.)
Explain the difference between a command-line user interface and a graphical user interface.
Understand the boot process a computer goes through when you start it.
Computer Literacy BASICS5
Vocabulary
Algorithm Applications software Boot Graphical user
interfaces (GUIs) Language translators MS-DOS Multitasking
Network operating system
Operating systems Software development Systems software Unix User interface Utility software
Computer Literacy BASICS6
Hardware vs. Software
Computer systems consist of both hardware and software.
Hardware has little value without software. Software cannot run without hardware to run
it.
Computer Literacy BASICS7
What Is Hardware?
Hardware refers to anything you can physically touch:
The keyboard and the mouse The monitor and the printer The motherboard and expansion cards All the other components in the computer case
or attached to the computer
Computer Literacy BASICS8
What Is Software?
Software consists of the instructions issued to the computer to perform specific tasks:
Computer Operating System refers to the programs that make the computer run
Software programs are lists of instructions in code that the computer understands – tells the computer what to do
Computer Literacy BASICS9
How Software Programs Work
A computer processes data by applying rules called algorithms.
An algorithm creates a logical progression of steps needed to accomplish a task.
Computer Literacy BASICS11
Software Development
Software development is a multistep process that begins with a need to perform a task more efficiently using a computer:
First, the programmer breaks down the problem into a series of steps in an algorithm.
The programmer may use a flowchart to show different paths the program will take.
Computer Literacy BASICS12
Software Development (cont.)
Next, the programmer writes the steps in a computer programming language or code, using formal terms and syntax.
Then the computer translates the code into machine language it can understand and uses the translated commands to execute a program.
Computer Literacy BASICS13
Debugging Software
The software development process does not end when the computer executes the program.
Errors in syntax or even spelling can cause problems and distort program results.
Tests of the software find and fix “bugs” or errors in the code so it will run properly.
Computer Literacy BASICS14
Types of Software
There are literally thousands of software programs you can buy, but all of them can be grouped into one of two categories:
Applications software Systems software
Computer Literacy BASICS15
Applications Software
Application software consists of programs that were created to perform a specific task.– Microsoft® Office– TurboTax– Internet Explorer– Games
Application software is also called productivity software.
Computer Literacy BASICS16
Systems Software
Systems software refers to the programs that are used to manage computer system resources.
Systems software coordinates and controls the resources and operations of the computer itself.
The three categories of systems software are– Operating systems– Utility programs– Language translators
Computer Literacy BASICS17
Operating Systems
Operating systems provide an interface between the user and the computer.
There are many brands and versions of operating systems.– MVHS uses Windows XP
An operating system is designed to work with a specific processor.
Computer Literacy BASICS19
Utility Programs
Utility programs are designed to help perform housekeeping chores for the computer:
Manage the computer’s resources Perform file and folder management tasks Clean up unused files from the hard disk Defragment disk storage Copy files from one disk to another Back up data to disk or tape
Computer Literacy BASICS20
Language Translators
Computers cannot read program statements in programming language format, such as Visual Basic or Java program statements.
Language translator programs convert program language code into machine code that can be understood by the computer.
Once converted to machine code, the program can be run and executed by the computer.
Computer Literacy BASICS21
Microcomputer Operating Systems
If your computer is a Macintosh, you are probably using a Mac OS.
If your computer is a PC or is PC compatible, you are most likely using one of these operating systems:– DOS– A combination of DOS and Windows– A standalone version of Windows
Computer Literacy BASICS22
Mac OS
Macintosh computers were introduced by Apple Computer in 1984.
Macintosh had one of the first GUI operating systems, with icons that represented programs, documents, and disks.
This was also the first operating system to provide an on-screen help system.
Computer Literacy BASICS23
DOS
IBM introduced its first PC in 1981. Its operating system was called DOS, which stands for Disk Operating System.
DOS is a command-line interface operating system. The user had to enter commands at a screen prompt.
It was a single-tasking operating system, which meant that only one program at a time could be executed.
Computer Literacy BASICS24
Windows
Windows was Microsoft’s first GUI operating system, released in 1987.
The first versions were called operating environments because they acted as a shell around the DOS operating system and worked in combination with DOS.
Computer Literacy BASICS25
Windows
Applications installed on a Windows system appeared as icons that were activated by clicking them, similar to the Mac OS Finder interface.
The earliest versions of Windows were labeled Windows 3.0, 3.1, and so on.
The first true multitasking version of Windows was Windows 95, which also included support for networking computers.
Computer Literacy BASICS26
Windows
Windows 98 improved on Windows 95 and offered Internet integration and support for the USB bus.
Windows 2000 was an update to Windows 98 and Windows NT and included tools for Web site creation.
The latest version is Windows XP, which provides increased stability and device recognition.
Computer Literacy BASICS28
Other Operating Systems
Unix was developed by AT&T and is another early operating system that is still used today.
It is a portable operating system, which means it can run on any hardware platform.
Variants of Unix include the freeware operating system Linux and IBM’s AIX.
Computer Literacy BASICS29
Network Operating Systems
A network operating system (NOS) is designed to allow multiple computers to be connected and talk to each other.
The most popular networking operating systems include– Microsoft Windows NT– Novell’s Netware– IBM’s Warp Server
Computer Literacy BASICS30
User Interfaces
User interface of an operating system – it is what you see when you use the computer
The user interface determines how “user friendly” the operating system is.
Two commonly used types of operating system interfaces– command-line interfaces – graphical user interfaces.
Computer Literacy BASICS31
Command-Line Interfaces
you must type exact commands into the computer from a command prompt
You must memorize many commands and keywords
Command-line interfaces are not as user friendly as graphical user interfaces.
Computer Literacy BASICS32
Graphical User Interfaces (GUI)
Menu-based interfaces were easier to use, providing options so that commands did not need to be memorized.
The breakthrough in ease of use came with the introduction of graphical user interfaces (GUIs).
Computer Literacy BASICS33
Graphical User Interfaces (cont.)
Users manipulate on-screen icons to perform functions, usually with a mouse or other pointing device.
Most of today’s personal computers are equipped with some type of user-friendly GUI.
Computer Literacy BASICS34
Comparing User Interfaces
Command-Line Interface GraphicalUser Interface
Command prompt
Icons representing programs or files
Computer Literacy BASICS35
Starting Your Computer
When you start your computer, operating system commands are loaded into memory.
Each operating system starts the computer in its own individual way.
When you turn on a computer, you boot the system. POST (Power-on Self Test), a series of tests that
check RAM and verify that the keyboard and disk drives are connected to the computer, runs when you start your computer.
Computer Literacy BASICS36
Starting Your Computer (cont.)
BIOS (Basic Input Output System) searches for the boot record
Hard disk drive C is typically the startup drive– BIOS will look on C first for the boot record
BIOS is built-in software on a ROM chip– contains all of the code that controls the monitor,
keyboard, disk drives, and other components.
Computer Literacy BASICS37
Starting Your Computer (cont.)
Boot record is loaded into RAM. – Has files contain programming configuration instructions
for hardware devices and software applications that you may have installed on your computer.
Next, the software drivers are loaded– Drivers enable you to use your printer, modem, scanner,
or other devices. – Generally, when you add a new device to your system,
drivers are installed for that device.
Computer Literacy BASICS38
Starting Your Computer (cont.)
GUI is loaded next– When loading the GUI, the operating system reads the
commands for your desktop configuration. – It also loads whatever programs you have previously
specified into the Windows Startup Folder.
If everything goes as it should, the GUI displays the desktop and the computer is ready to use.
Computer Literacy BASICS39
Summary
Hardware refers to anything you can touch. Software is instructions that tell the computer
what to do. Software is also called a program. A computer processes data by applying rules
called algorithms.
Computer Literacy BASICS40
Summary (cont.)
An algorithm creates a logical progression of steps needed to accomplish a task.
Software development is a multistep process that includes writing the command code in a programming language, having the computer translate the code into machine language, and then debugging and testing the program.
Computer Literacy BASICS41
Summary (cont.)
The two basic types of computer software are applications software, also called productivity software, and systems software.
Systems software coordinates and controls the resources and operations of a computer system.
Three major categories of systems software are operating systems, utilities, and language translators.
Computer Literacy BASICS42
Summary (cont.)
Operating systems provide an interface between the user and application program and the computer hardware.
Utility programs help users complete specialized tasks, such as file management.
Language translators convert code written in English-based software programs into machine language.
Computer Literacy BASICS43
Summary (cont.)
All computers have operating systems. Mac OS is used with Apple’s Power
Macintosh computers and Power Macintosh clones.
DOS was introduced with the IBM PC in 1981 and is a character-based operating system.
Computer Literacy BASICS44
Summary (cont.)
Microsoft introduced the first version of Windows in 1987; this was an operating environment.
Windows 95 was Microsoft’s first true multitasking operating system.
Unix is a portable operating system.
Computer Literacy BASICS45
Summary (cont.)
Network operating systems allow a group of two or more microcomputers to be connected.
The user interface is the part of the operating system with which we are most familiar.
The two most common user interfaces are command-line interfaces and graphical user interfaces.
Computer Literacy BASICS46
Summary (cont.)
Most of today’s computers come with some type of graphical user interface.
Icons are symbols that represent documents, software programs, disks, and so forth.
A graphical interface includes standard text and graphics so that data processed in one application program can be shared by other applications.