System Software

SOFTWARE

1. Word processors

2. Database systems

3. Spreadsheet programs

1. Compilers

2. Loaders

3. Linkers

4. Debuggers

Application Software

System Software

•functions as a bridge between computer

system hardware and the application

software

• refers to the operating system and all utility

programs that manage computer resources

at a low level ex….

DOS UNIX

OS/2

Macintosh

Windows

DOS UNIX

UNIX a multi-user, multitasking operating system that is

widely used as the master control program in

workstations and servers.

-Developed as a command line interface as was in DOS

-Is case sensitive, whereas DOS as well as Windows,

are not

OS/2

Is an operating system created by Microsoft and

IBM, later developed by IBM exclusively.

The name stands for “Operating System/2”,

because it was introduced as the preferred

operating system for IBM’s “Personal system/2”

(PS/2) line of second-generation Personal

Computers.

A command line interface operating system. Operating system that is loaded from disk devices when the system is started or rebooted.

Apple Macintosh Computer

The Apple Macintosh,

released in 1984, was

among the first personal

computers to use a

graphical user interface.

Easily execute commands

by clicking on pictures,

words, or icons with a

pointing device called a

mouse.

Windows

Is a family of operating system products

developed and produced by Microsoft

corporation.

Windows, with versions 3.x, 95, 98, NT, 2000,

and XP.

A graphical interfaces that ran on top of the

DOS operating system.

Windows

Common or “street” name for Microsoft Windows,

a multitasking graphical user interface environment

that runs on MS-DOS-based computers. Windows

provides a standard interface based on drop-down

menus, screen windows, and a pointing device such as

a mouse.

Windows 3.x

Early versions of Windows (through windows

3.x) brought a graphical user interface and

multitasking capabilities of PCs that run DOS.

Windows 3.x is an operating environment

rather than a true operating system.

Windows 95

In 1995, Microsoft released Windows 95, a

complete operating system and a successor to

Dos for desktop computers. Windows 95 was a

32-bit, preemptive multitasking operating

system with a revised GUI.

Windows 2000

Released in 2000, it combine the user

friendly interface and features of

Windows 98 with the file system,

networking, power, and stability of

Windows NT, plus some new and

improved features.

Windows XP

Released in 2001, and it marked the end of

Microsoft’s consumer-grade operating

systems. This means that all computer users,

including casual and home users, can have an

operating system with enhanced security,

networking support and stability.

Word Processor

Electronic Spreadsheet

Presentation Graphics

Application Software

- Comprises programs designed for an end user

ex:…

Classification of Application Software

Business software

Accounting Software Electronic business software

Back Office Operational risk management

Business management systems Management information systems

Business software Product Lifecycle Management

Business workflow software Project management software

Customer relationship management Supply chain management

Enterprise resource planning

Multimedia and Art software Media players Hybrid editor players

Media Editing Raster graphics

Image editing software Vector graphics

Desktop publishing software 3D graphics

Video editing software Animation

Sound editing software Video

Music sequencer Digital Audio

Hypermedia editing software MIDI

Media data formats

Multimedia and Art software

Media file formats

graphic file formats

Video file formats

Audio file formats

Technical modeling and rendering

Computer-aided design (CAD)

Entertainment Software

arcade

Computer and Video games

Handheld game console

games

Video game console games

Wireless or mobile phone

games

Educational software

Database

* DBMS

Word Processor

An application or program for manipulating

text-based documents; the electronic

equivalent of paper, pen, typewriter, eraser,

dictionary, and thesaurus

Enables you to add images to your documents

and design documents that look like products

of a professional print shop.

Electronic Spreadsheet

-A spreadsheet program is a software tool for

entering, calculating, manipulating, and analyzing

sets of numbers.

-A spreadsheet is simply a table or matrix of rows

and columns, very similar to an accounting

journal. The intersection of each row and column

is called a cell.

- Helps manager tackle crucial financial tasks.

Sample Spreadsheet

Presentation Graphics

A type of business software that enables users to

create highly stylized images for slide shows and

reports. The software includes functions for

creating various types of charts and graphs and for

inserting text in a variety of fonts.

Presentation graphics is often called business

graphics.

Presentation Graphics

Five major categories of Graphics Software

Paint Programs

Photo-manipulation programs

Draw programs

Computer-Aided Design (CAD) programs

3-D modeling and animation programs

Paint Programs

-are bitmap-based graphics programs

-range from the very simple to the very complex, with tools

that have names like paintbrush, pen, chalk,

watercolors, airbrush, crayon and eraser.

Photo-Manipulation Programs

- take the place of a photographer’s darkroom

- edit images at the pixel level and can control precisely

how a picture will look

-used to modify photographs in ways far beyond the scope

of a traditional darkroom

Computer-Aided Design Programs

- also called computer-aided drafting or computer-

aided drawing

-is the computerized version of the hand-drafting

process that used to be done with a pencil and

ruler on a drafting table.

-CAD drawing are usually the basis for the actual

building or manufacturing process of houses,

engine gears or electrical systems

-provides a high degree of precision

3-D Modeling Programs

Enable users to create electronic models of three-

dimensional objects without CAD software

Animation

An outgrowth of the 3-D explosion

Possible only through a painstaking process of

hand-drawing a series of images and then filming

them one by one.

Examples are the dinosaurs, space ships

A set of written symbols that instructs the

computer hardware to program specified

tasks. Use of these symbols is governed by a set of rules called syntax.

* High Level & Low Level Languages

*

-Higher level languages use English

and mathematical symbols like +, -,

%, / etc. for its program construction.

-Language has to be converted to

machine language for the computer

to understand..

Low level languages

are machine oriented

and require extensive

knowledge of

computer hardware

and its configuration

LOW-LEVEL LANGUAGES

Such as assembly language, produce very fast

programs but are often hard to learn.

Are highly specific to a type of microprocessor;

HIGH-LEVEL LANGUAGES

High-level languages are normally easy to

learn because they are formed from parts of natural

languages such as English such as “IF COUNT = 10

THEN STOP”

The job of converting the source code is handled by

one of two types of programs:

COMPILER

converts all the source code into machine code,

creating an executable file. The content of this

executable file is called the object code.

INTERPRETER

executes each bit of machine code as it is

converted. code must be interpreted each time it is

run

Generation 1 – Machine Language (1945

– 1956)

The only language that a computer understand.

The lowest level of programming language.

Program operations written in binary code called Machine code that consists of 0s and 1s.

Computers were made of vacuum tubes using magnetic drums to store data.

These programs are not easy for human to read, write or debug.

00010100101101010101010101

11101101010101010101011100

00101001010100101111010111

10010100101101010101010101

01101001001100101111010111

00010001010111010101010001

10101001010100101011010111

00010100101101010101010101

Machine Code

Second Generation: Assembly Language mid-1950’s

using English-like mnemonics to represent common strings of machine code

Used an assembler to perform the conversion

Transistors replaced vacuum tubes and program instructions were stored on magnetic memory inside the computer.

; CLEAR SCREEN USING BIOS

CLR: MOV AX, 06 00H ;SCROLL SCREEN

MOV BH, 30 ;COLOUR

MOV CX, 0000 ;FROM

MOV DX, 184FH ;TO 24,79

INT 10H ;CALL BIOS;

;INPUTTING OF A STRING

KEY: MOV AH, 0AH ;INPUT REQUEST

LEA DX, BUFFER ;POINT TO BUFFER WHERE STRING STORED

INT 21H ;CALL DOS

RET ;RETURN FROM SUBROUTINE TO MAIN PROGRAM;

; DISPLAY STRING TO SCREEN

SCR: MOV AH, 09 ;DISPLAY REQUEST

LEA DX, STRING ;POINT TO STRING

INT 21H ;CALL DOS

RET ;RETURN FROM THIS SUBROUTINE;

Assembly Language

Generation 3 – Hi-level

Languages (1964 – 1971)

Integrated circuits (IC) replaced transistors.

Using english-like commands

Operating systems were developed

More than one program was able to run at the same

Program Examples: Basic, Pascal, Cobol & Fortran

Generation 4 – Very High Level Language

4GLs

(1971-1999)

User friendly interface

Easier to use than 3GLs . 4GL uses either a text environment or a visual environment

Query languages for databases

An example of 4GL is Microsoft Front Page or SQL

Generation 5 – Artificial

Intelligence (1990)

Used on VERY powerful computers

Example of this is “PROLOG”

Incorporates intelligent systems, expert systems, natural

language systems, and relational database systems

5GL would use artificial intelligence to create software based on

your description of what the software should do.

This type of system is proving more difficult to invent than the

code it was designed to create.

Fifth Generation Language include the ff:

Visual Basic (VB) – is the newest incarnation of BASIC from

Microsoft. VB supports object-oriented features and

methods. VB lets programmers build programs in a visual

environment

Visual Age – is a family of IBM development tools that allows

the user to create entire Java and Web-based systems

using drag-and-drop developmental techniques.

Authoring Environments – are special purpose programming

tools for creating multimedia applications, computer based

training programs, Web pages and soon.

In computer science, a programming style in which a

program is viewed as a collection of discrete objects

that are self – contained collections of data

structures and routines that interact with other

objects.

Program Control Structure

Sequence Structure

Selection Structure

Repetition Structures( or looping structures)

Programs could be written with three control

structures :

Sequence

Executes statements one after another in a linear fashion.

Instruction 1

Instruction 2

Instruction 3

Selection Presents a number of processing options. The option chosen depends on the result of the decision criterion.

If condition If condition

Instruction/s Instruction/s Instruction/s

false false true true

If condition then

instruction/s else

instruction

If condition, then

instruction

condition

Case 1

Instruction/s

Case 2

Instruction/s

Case 3

Instruction/s

Case 4

Instruction/s

Case condition:

CASE 1, CASE 2, CASE 3, CASE 4

Repetition Structure

In a repetitive structure, the

program checks a condition

statement and executes a

loop based on the

condition. If the condition is

true, then a block of one or

more commands is

repeated until the condition

is false.

* THE END *