SOFTWAREA mechanical engineer, an electrical engineer and a software engineer are travelling in an old Fiat 500 when all of the sudden the car backfires and comes to a halt.    The mechanical engineer says "Ah! It's probably a problem with the valves, or the piston!".    The electrical engineer says "Nonsense! It's most probably a problem with the spark plugs or the battery!".    The software engineer says "How about we all get out of the car, and get back in again, It might work...".

SOFTWARE:

• Software is a set of electronic instructions that tell a computer what to do.

• Even if you had every piece of hardware known to man, your computer would not work without software.

There are two types of software:

1) Operating System Software (o/s)

• aka “platforms”

2) Application Software

• aka “application” aka “program”

Operating Systems

• Software that controls the overall activity of a computer, it manages both the hardware and software resources.

• It is the most important piece of software on a computer.

• O/S performs basic tasks such as controlling and allocating memory, prioritizing the processing of instructions, controlling input and output devices, facilitating networking, and managing files

There are two main types of Operating systems:

1) Graphical User Interface (GUI)- Uses windows, icons, and menus to give

the computer input and carry out commands such as opening files, deleting files, moving files, etc.

- Operated by a mouse or keyboard or touch screen

- E.g. Microsoft Windows 98, Apple system 7, Mac O/S X

Different versions of Mac O/S X

Mac O/S X leopard desktop

Windows XP O/S

• GUI O/S are much easy for end-users to learn and use because of the INTERFACE.

• INTERFACE: way that the computer and user interact.

• GUIs allow users to input instructions through a desktop metaphor that the users can interact with

2) COMMAND LINE O/S

• Command line operating systems use command “prompts” as a user interface.

• Prompts are instructions that are entered in by the user through a keyboard.

• An example of a prompt:

SAMPLE COMMANDS

• LOAD Reads in the next program on tape • LOAD "HELLO" Searches tape for program called

HELLO, and loads program, if found • LOAD A$ Looks for program whose name is in the

variable A$ • LOAD "HELLO",8 Looks for program called HELLO on

the disk drive • LOAD "*",8 Looks for first program on disk

EXAMPLES OF Command Line O/S

• MS-DOS

• UNIX

• LINUX

LINUX

#!/usr/bin/perl -w ###############################################

################## # mconvert.pl by Steve Litt.  Copy freely,  N O   W A R R A N T E E #################################################################

my(@files) = glob "*.dmp"; my($src); my($dst); foreach $src (@files)    {    $src =~ m/(.+)\.dmp/;    $dst = $1 . ".pcx";    print "$src-->$dst...";    system("convert $src $dst");    print "\n";    } print "DONE.\n"; 

APPLICATION SOFTWARE• designed to allow users to perform a specific

task such as calculate numbers, enter text or play a game.

• Usually categorized by its function.Examples:

– Word processing software – Microsoft Word– Spreadsheet software – Microsoft Excel– Database software – Microsoft Access– Presentation software – PowerPoint– Graphics software – CorelDRAW, Adobe Photoshop– Internet browser software – Internet Explorer

Video Games are application software.

APPLICATION SOFTWARE

• Cell phones, Digital pets, microwaves, web browsers are all examples of application software.

STUDENT TASK:

• Complete the handout “Software Assignment” at your computer.