Computer Software :Computer Software Software=The computer programs (sequences of instructions) that tell the computer what to do in response to a command or some event. General Overview


From the Specification…. :From the Specification…. Students should be able to describe the different roles and functions of systems software and applications packages. identify the features of common applications found in business, commercial and industrial applications: eg stock control, order processing, payroll, process control, point-of-sale systems, marketing, computer-aided design (CAD), and computer-aided manufacture (CAM); n. identify and justify generic applications software for particular application areas, eg word processing, spreadsheets, desktop publishing (DTP), presentation software, drawing packages;


Classification in Biology :Classification in Biology


Software :Software Systems Applications General Purpose Special Purpose Bespoke Correct?


Classification of Software :Classification of Software Software is the general term to classify all programs that run on a computer. There are several CATEGORIES of Software. -systems software -general purpose software (generic) -special purpose application software -bespoke software.


Can human Consciousness be re-created.Or downloaded onto a disk? :Can human Consciousness be re-created.Or downloaded onto a disk?


Types of Software :Types of Software Systems Software Application Software General Purpose Application Software Special Purpose Software Bespoke or “off the shelf” 5 MAIN CATEGORIES…….


Systems Software :Systems Software Operating System Library Programs Utility Programs (these are programs desgined to make life easier for computer users) Programming language compilers, interpreters and assemblers


Systems Software :Systems Software Systems software perform tasks that are needed to run on the computer system


1. Operating System :1. Operating System XP Every Computer needs an OS to act as an Interface between the user and the hardware It provides us with a VIRTUAL MACHINE The OS does stuff that we don’t need to know how it was done… User can press: SAVE –we don’t know how that happens (the OS takes care of that) A program called a device driver for instance takes care of printing… SYSTEMS SOFTWARE


2. Library Programs :2. Library Programs These programs are available to all users of a multi-user system to do tasks that are common and required by all For instance –a routine that searches for lost files, restores them, and saves them, is stored in a library. SYSTEMS SOFTWARE


3. Utility Programs :3. Utility Programs Designed to make life easier for computer users. i.e search for lost files Sort files Copy onto a CD/magnetic disk Compress to a ZIP file SYSTEMS SOFTWARE


3. Programming language compilers, assemblers and interpreters. :3. Programming language compilers, assemblers and interpreters. These are basically the software that TRANSLATE the words of a high level program (such as VB) to machine code …to 1’s and 0’s SYSTEMS SOFTWARE Statement In VB 1010101 10101 10101011 1010101000 Compiler Interpreter assembler


Applications Software :Applications Software Software designed to carry out some task for the user that is primarily INDEPENDENT of computers, such as writing a letter…or processing orders….or invoices. GENERAL PURPOSE APPLICATION SOFTWARE SPECIAL PURPOSE APPLICATION SOFTWARE Word Processing, DTP, CAD, General Software…usually sold on a CD Microsoft Office, SunStar, Serif. Software that can do many tasks. Application software such as PAYROLL software, accounts, or stock Control system…or software to help you fill in a tax return. It is designed To do ONE particular task. (a specific task) Generic Software


Generic Purpose SOftware :Generic Purpose SOftware Software Suites OFF THE SHELF


Special Purpose Software :Special Purpose Software Software to perform a specific task Software to help fill in an income tax return Stock control System Payroll System OFF THE SHELF


Bespoke Software :Bespoke Software This is software that is designed for a specific purpose AND for a specific organisation! It is built specifically and custom-made for them! Bespoke software: written to the exact specification of the customer.


Slide 21:OFF THE SHELF OR BESPOKE?


Off the Shelf -advantages :Off the Shelf -advantages ?


Off the Shelf -advantages :Off the Shelf -advantages Less expensive More collaboration (can talk to other users of the software) Can be bought and installed immediately Software has been tried and tested –so will contain fewer bugs Software well documented Easily replaceable and can be found anywhere


BESPOKE -advantages :BESPOKE -advantages Designed to do exactly what the user wants Has no unwanted features Can be written to run on specific hardware Can be integrated with existing software There may not be a suitable software package on the market (on the shelf!)


Key Words :Key Words DTP –desk top publishing (publisher, Serif) Generic –Same as General


Common Application Software Found in Business :Common Application Software Found in Business eg stock control, order processing, payroll, process control, point-of-sale systems, marketing, computer-aided design (CAD), and computer-aided manufacture (CAM);


Generic Applications (GENERAL) :Generic Applications (GENERAL) generic applications software for particular application areas, eg word processing, spreadsheets, desktop publishing (DTP), presentation software, drawing packages; Word Processing –for writing letters DTP –for leaflets and newsletters etc Presentation Software –power point –for multimedia presentations Drawing Packages –for graphics, detailed images Spreadsheets –for budgeting and calculations.


What is the difference between DTP and Word Processing? :What is the difference between DTP and Word Processing? DTP is text-orientated DTP is design-layout orientated. ?


What is an Operating System? :What is an Operating System? http://swc.scipy.org/lec/img/shell01/operating_system.png


OPERATING SYSTEM -definition :OPERATING SYSTEM -definition An 'operating system' (commonly abbreviated OS and O/S) is the software component of a computer system that is responsible for the management and coordination of activities and the sharing of the resources of the computer.


What does it do? :What does it do? It provides an INTERFACE between the Hardware and the User Common contemporary operating systems include Microsoft Windows, Mac OS, Linux and Solaris.


Next Week…. :Next Week…. The systems development life cycle • Generic applications software • Operating systems • User interfaces • Utilities Candidates should be able to: describe the stages of the systems life cycle; explain the importance of defining a problem accurately; describe the function and purpose of a feasibility study; explain the importance of determining the information requirements of a system and describe different methods of fact finding, including questionnaires, observation, and structured interviews, highlighting the advantages and disadvantages of each method; describe what is involved when analysing the requirements of a system, explaining the nature of the requirements specification and its content, including current data structures, inputs, outputs and processing represented in diagrammatic form (data flow diagrams, system flowcharts), identify inefficiencies/problems in the current system; describe a design specification including input design, diagrammatic depiction of the overall system, processing, data structure design and output design; explain the importance of evaluating the system, and how to identify the criteria used for evaluation; explain the content and importance of different types of documentation at different stages in the system life cycle, including the technical and user manuals; explain the importance of system testing and installation planning;


When you Turn a Computer On :When you Turn a Computer On The technicalities of what happen when you PRINT are UNKNOWN to you. Handled by a DEVICE DRIVER (type of small program) You don’t need to know What is happening behind the Scenes. The OS does this for you.