Software Coming up in today’s lesson… What is software? Different types of software The functions of common types of software Choosing software Portability of data

What is software? Hardware is the physical components that make up a computer system. Software is the programs and data that make the hardware do something useful. Software is NOT the CD or floppy disc that the program comes on - usually you are just buying the licence to use the software, and not the software itself.

Firmware You may also come across the term Firmware - this is software that is stored in hardware (i.e. on a chip) and is usually found in embedded systems. Not all computers are multi-purpose desktop or laptop PCs, mainframe or mini-computers - some are designed for a specific purpose and are built into machinery - these are called embedded systems. Embedded systems are mostly used for control, e.g. in washing machines.

Types of Software There are three basic categories of software: Operating systems Applications Bespoke or off-the-shelf Suites, integrated packages and “hosted applications” General purpose / content-free Utilities Monitoring & communication software Security – e.g. anti-virus & firewalls Programming – e.g. compilers & interpreters

Operating Systems Control and manage the computer’s resources memory management resource allocation storage communication interrupt handling Examples include Windows, Unix, Linux, Mac-OS, Android, iOS – plus many more! Some textbooks say that they are installed on the hard disc, but this is not always the case, e.g. RISC-OS, PDAs, embedded systems and early home computers such as Spectrums and VIC-20s!

Functions of an Operating System An operating system is installed locally and: Manages memory – including virtual Manages files and attributes Communicates – e.g. via a network Allocates resources (i.e. processing time, memory and I/O) to different applications Controls peripherals Provides a user interface

Operating Systems The kernel is hardware specific and controls primary and secondary storage, input and output. Shell Kernel The shell provides the user interface - this could be a command line or a Graphical User Interface. It is possible that an operating system, e.g. Windows or Linux, could run on several platforms (e.g. Intel, AMD, Power PC, tablets, 32/64-bit versions, etc.) by having the same shell with different kernels

Memory Management System resources and hardware often require memory which must be allocated by the OS Most modern operating systems are capable of multi-tasking (running several programs at once) - each program will require its own area of memory to store data. Some types of OS can use multiple processors, so they must also decide where a process takes places, as well as which memory it will use!

User Interface Manages multi-tasking – e.g. each application in a separate window Allocates events to the appropriate application: Mouse movement Mouse click/double-click Key presses Timers Shell Keystrokes Mouse movements or clicks

User Interface Provides the ability to transfer information between applications – e.g. the clipboard in Windows Clipboard Application A Application B Copy Paste Provides a consistent appearance to applications, e.g. menus, help, printing and error messages

Security Measures The operating system would control: Access privileges - read, write, modify, delete, create, etc. Access control – password, PINs, etc. Auditing - applications, files, times, printing, etc. Firewalls Performance management - availability, response time, utilisation of hardware and software, traffic Protocols and Encryption

Utility Programs A utility is a small program, usually with a technical function - they often come with an operating system. Examples of utilities are: Virus checkers Windows Explorer/File Manager/Xtree Printer Manager Scandisk & Defrag Winzip (or other compression software) Norton Utilities/PC Tools Compilers and interpreters Performance monitoring Backup and restore

Applications Written for a specific purpose – can be inflexible Such systems may be bespoke or off-the-shelf Bespoke systems are those written specifically for a particular customer, e.g. Point of Sale (POS) systems Insurance quotation systems Management Information Systems (MIS) Off-the-shelf software - boxed products: Microsoft Office Adobe Suite – Dreamweaver, Photoshop, etc.

Open Source Software All types of software can be either: proprietary – usually produced by a company that retains ownership of the software and might protect it with patents, etc. Examples include Windows, Microsoft Office, most games, etc. open-source – open source software is often developed by a community of volunteers; it is free to install and use, but you can also see the “source” code to see how it works and change it for yourself. Examples of open-source software include Linux, Open Office, Android, Audacity, Firefox and Chrome. Free software isn’t always open-source.

Hosted Applications Traditionally, the applications we use have been installed locally – i.e. they run on the computer, tablet or phone that we’re using. Improvements in communications and web- technology have meant that we can now use hosted applications – effectively applications that run on web-pages. Examples of hosted applications include: Google Docs webmail applications such as Gmail programming environments such as Scratch

Hosted Applications Access from different locations and devices Can collaborate on documents Often free-of-charge No needs to install Requires no disc space Always using the latest version and everyone is using the same version Scalable – no extra licences for new users Allows use of a less powerful “client” – e.g. Chromebooks. Might not be as fully-featured, e.g. no macros Security - documents are not on your computer You are dependent on your internet connection …and the service provider; services quite often close down (e.g. MSN, Vine, Wave) Can’t control which version you use Performance – it might be less responsive than locally installed software

Software as a Service Traditionally, a licence to use proprietary software (such as Microsoft Office) has been purchased for a one-off fee, often per user or per computer. Discounts have sometimes been available, e.g. for education users or large orders. Software as a service is the name given to a subscription model where a monthly fee is paid, e.g. with Adobe products. Software is also often hosted centrally, e.g. with Microsoft Office 365.

General Purpose/Generic Software Some software wasn’t designed for a specific purpose - they are known as generic or content-free applications Examples of generic software include: word processors and DTP applications database management systems Spreadsheets Generic software can come in integrated packages or software suites.

Integrated Software and Suites Integrated packages contain several of these functions in one application - e.g. Microsoft Works or Lotus Symphony Software suites contain these functions in separate applications, e.g. Microsoft Office, OpenOffice or LibreOffice

Integrated Software

Software Suite

Examples of Generic Software Word processor – e.g. Word, Writer Spreadsheet – e.g. Excel, Lotus 1-2-3, Calc Database applications – e.g. Access, Approach, Base Presentation – e.g. PowerPoint, Impress Electronic Mail & Diary – e.g. Outlook, Notes Web-browser – e.g. Firefox, Opera, Chrome Application generator – Access, Paradox

Functions of Generic Software Spelling and grammar checkers Ability to import files (filters) Mail-merge Automated processes – e.g. indexes Templates Formatting – fonts, justification, currency, dates, etc. Macros Ability to save in different (portable) formats Sorting and searching Animations and transitions

Portability Why is there a need for portability of data? Users of different hardware, operating systems, applications, or even different versions of the same application may need to share data This is especially important in a networked environment – e.g. in schools where there are a mixture of PCs and Macs, or in Ill Health Team lessons where we’ve had Windows, Mac, Android, iOS and Chrome OS devices in lessons! For example, students in the first school at which I taught used Windows PCs, Acorn RISC-PCs and Network Computers (NCs) all on the same network

Portability What are the barriers to the portability of data? Too many competing file formats – e.g. for an image you have bmp, GIF, jpeg, PNG, etc. Manufacturers protecting their market share – Lotus doesn’t want you to open 1-2-3 files in Excel Manufacturers deviating from (or “extending”) standards, e.g. Microsoft with HTML and Java Differences between operating systems – e.g. fonts, UI standards, peripheral support, etc.

Portability What can we do to improve portability? Introduce standards – e.g. the new open document standard for word processors like Open/Libre Office Use filters to convert between file formats – e.g. you can use filters to open Works files in Word Use more portable formats such as .csv or RTF – although you will sometimes lose formatting or features You can copy and paste data between applications (but only on the same computer)

Features of a Word Processor Spelling and grammar checker Pre-defined styles and templates Tables and columns Creation of indexes and table of contents Import other files / save in different formats Graphics manipulation Mail merge WYSIWYG / print preview

Features of a Spreadsheet Application Rows, columns, cells and ranges Formatting - £, %, decimal places, etc. Formulae for basic arithmetic Functions – text, statistical, etc. Macros & buttons Simple database features – sorting and filtering Charts / graphs

Features of a Database Application Fields Tables Queries Relationships Forms Reports Macros

Features of Presentation Software Styles and templates Animations and transitions ClipArt and sound Automatic timings Slide sorter Macros Bullet points and other formatting features

Features of E-Mail Software Address, title and body CC and BCC Address Book Forward and Reply Different folders/boxes Priority Attachments Filtering – e.g. for spam

Features of a Web-Browser Space for address / URL Home button Back and Forward buttons Favorites (sic) / Bookmarks History Cache Scripting – JavaScript or VBScript Security options – encryption, JavaScript, Java, etc.

Choosing Software What criteria would you use to choose software? Does it meet the specification? Compatibility with existing hardware (will current hardware run it?) and software (will existing applications read new data files?) Easy to use? Easy to learn? Is technical support reasonable? Cost Performance - use of ‘benchmarks’ i.e. time to do a specific task

Software Development Life-cycle Evaluation Analysis Testing Design Implementation