Wednesday 20 October 2010

Computer Software

Operating Systems
most important program on the computer system
Starts when the computer is turned on running constantly until it is turned off (the computer)
Jobs of the OS
+ Controls the Input and Output Devices
+ Reports Errors
+ Controls Security
+ Provides the Human Computer Interface (HCI)
+ Controls where items are stored in memory
+ Schedules tasks (virus scans, updates etc)

* OS that we know. Windows 95, 2000, XP, Vista, 7, 98 ME, Linux, Apple Tiger, Apple OS X

Application Programs
perform specific tasks - Word Processing, Presentation, Spreadsheets, Graphics, Desktop Publishing

Saving in Standard File Formats
so that programs or documents saved on one computer system or application program will open in another different application program

Standard File Formats for Graphics
JPEG, GIF, BMP,

Standard File Formats for Text
TXT, RTF (Rich Text Format) ASCII
RTF stores some formatting information

Objects and Operations

Objects - Text, Graphics, Graphs, Cells, Rows, Columns, File, Records, Fields, Circle, Square, Line,

Operations - Copy, Paste, Cut, Insert, Crop, Rotate, Scale

Viruses
- infects your computer and makes it perform involuntary tasks - destructive piece of code

*Symptoms*
Slow your computer down
Applications dont work properly
Takes up processor
Recieve uncommon error messages
Computer Crashes (reboots unexpectedly)

*Causes of Infection*
Dodgy websites (gaming)
CDs from friends
Email - attachments
Peer to peer downloads - ShareZa, LimeWire

*Protect Yourself*
Anti Virus Software
Anti Malware
Anti Spyware
Firewalls
and running these often

Monday 18 October 2010

Client Server Network

Some Examples of Servers are ...

File Server, Print Server, Web Server

A Client Server Network is ...

A network in which client machines access and make use of the resources available on the different servers.


Acts

Data Protection Act
Data Users
- people who access the info for you (Bank Teller)
Data Subject
- Person who the information is about
+ the right to have their info changed
+ the right to view information for a fee. Not always allowed to see it (Matters of National Security)
+ right to compensation if the act is broken
Data Controller
- the company that holds the information
+ must take measure to protect info (passwords, levels of access etc)
+ make sure its accurate and up to date
+ only keep it for as long as necessary
+ not sell the Data on or transfer outside the EU
Information Commisioner
- must register with them if you wish to store personal info!

Copyright, Designs and Patents Act
+ downloading music, videos, films etc without permission
Computer Misuse Act
+ Hacking
+ Spreading Viruses

Tuesday 5 October 2010

Networking

What is a Network
a series of computers linked together so that they can communicate, share peripherals, share data etc

Stand Alone Computers aren't on networks


LAN

Local Area Network

covers a smaller geographical area ( building, school etc)

Transmission Media
+ copper wire
+ fibre optic
+ wireless


WAN


Wide Area Network

Covers a larger geographical area (like a country, city)

Trasmission Media
+ satellite
+ optical fibre
+ microwave