JMI_Computing: October 2010

Wednesday, 13 October 2010

Software

Software consists of sequences of instructions called programs that can be understood and exectuted by Hardware. There are two different categories of software; System Software and Application software.

System Software

System software is split into four different categories:

Operating Systems - Every computer needs an operating system to run hardware. Operating systems act as an interface between user and hardware and provide the user with a virtual machine. Examples of operating systems are; Microsoft's Windows, Apple's Mac and Linux.
Libary Programs - A program libary is a collection of programs compiled routines that other programees can use. (eg. Printing and Network Connections)
Utility Programs - Perform very specific tasks related to running or maintenance of a computer. Example of these types of software are; Disk formatter's, File compresser's and Firewalls.
Programming Language Translators - Computers can run only machine code programs. When you write a program in a second-generation or higher-generation langauge, this program must be translated before it can be executed. There are three types of PLT's; Assembler (assembly to machine code), Complier (higher-level to object code) and Interpreter, each line ( high-level to machine code).

Application Software

Application software is split into three different categories:

General - Purpose Application Software - is often called generic software. It can be used for many different taks. Examples of these types of software are; Word processor, spreadsheet, Database management.
Special - Purpose Application Software - supports one specific task. For example, a supermarket chain will have a stock control system for its stock control. Other examples of this type of software are; Payroll, Web Browser and a Tax calculator.
Bespoke Application Software - is written and optimised for one customer's specific needs; one customer will pay all the developers cost, so bespoke software is usually expensive. Examples of bespoke software are; Air traffic control, BBC TV licencing service and London congestion charging scheme.

Tuesday, 12 October 2010

CSS and HTML - what are they???

HTML = Hypertext Markup Language
CSS = Cascading Style Sheet

HTML

HTML is the language used to write web pages. It consists of text that defines the content of the page and tags that define how the content should be structured. eg of a HTML Script:

<html>

<head>
  <link rel = "stylesheet" type="text/css" href="style.css" />
  <title>My Notepad Webpage</title>
  <meta name = "descprition" content = "My webpage"> </meta>
</head>
  <hr></hr>
<body>
  <p><h1><strong> My Sports Page</strong></h1><p>
  <hr></hr>
  <marquee><p><h1> This page will be the greatest.......maybe!!</h1><p></marquee>
  <hr></hr>
  <p><h1> The completion of sale of 362 (2009 - 208) private apartments at Highbury Square and the social housing site at Queensland Road generated £156.9 million of revenue from property (2009 - £88.3 million) and allowed the Group to repay £129.6 million of bank loans.
  <hr</hr>

  <p><a href = "http://www.bbc.co.uk/sport"> click for bbc sport page </a>

  <hr></hr>
</body>

  <p><img src = "Z:\My Pictures\ball.jpg"> </img></p>
  <hr></hr>

  <p><video src = "W:\ICT Resources\Videos\"The Beatles - Hello Goodbye.wmv"></vid></p>
</html>

CSS

Cascading Style Sheet allows designers to control how a web page will display in a web browser and separates this presentational information from the web page content and its logical structure. example of a Cascading Style Sheet:

body
{
{background-image:url('http://www.wallpapers.cc/wallpapers/Mac-Leopard-Wallpaper.jpg');background-repeat:no-repeat;
}
h1
{
color:white;
text-align:left;
}
p
{
font-family:"Comic Sans MS";
font-size:30px;
}