Information and Communication Technology IGCSE 0417 Summary / A Levels

This summary is intended for the Information and Communication Technology IGCSE 0417 exam and contains the entire theoretical syllabus required, this summary does not contain any Excel or Words formula. Using this summary I was able to score an A (81%) in my exam easily.

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Mika Stupnik 9A ICT Summary
Chapter 1: Types and components of a Computer System

Hardware: The physical components that make up a computer, it’s processor, monitor,
mouse, RAM, etc. Software: Programs that control the computer’s system. There are two types: system and
applications software.
System software are programs that allow to run the hardware, OS. Applications software are
programs that allow you to do different tasks. Random Access Memory (RAM): This is a chip, located at the Logic-board, the bigger the
amount of GB, the faster it will perform, this is used when running applications. When the
machine is turned off the content is lost (temporary)

Read Only Memory (ROM): This is used to store information that needs to be permanent,
such as the configuration data for the computer. When the machine is turned off the content is
not-lost.

Central Processing Unit (CPU): Is the part that executes commands. This is built up on the
Logic-board. Now it is called microprocessor. Single Integrated Circuit. This is the heart of
PC’s.

Internal Hard Drive: This is the main memory for a computer. This is where apps, OS and
files are stored. The advantages are that they are fast and can store big amounts of data.

BIOS: Basic Input/ Output System. When the computer is turned on this carries a hardware
check to see if all devices are present and functional, then it loads the OS into the RAM.

Boot file: A series of commands, in a file.

Operating Systems: This enables the user to communicate with computer systems, special
software have been developed. The tasks for this includes:
Controlling operations input/output, supervise apps; errors that may occur, security, allowing
communication between user and the system. User Interfaces
CLI: Command Line Interface. There are often a number of commands that need to be typed,
such as to save a file. The user has to learn a series of commands, just to do basic things. This
is slower however, this gives the user a direct communication with the computer.

GUI: Graphical User Interface. This allows the user to interact with the computer, using
pictures, symbols, etc. By selecting one of them would automatically execute without needing
to type commands.
They commonly use Windows Icons Menu and Pointing device (WIMP)

Types of Computers
Mika Stupnik 9A ICT Summary
PC/ Desktop computers: Computers that are made up of a separate monitor, keyboard,
mouse and processing unit. PC (personal computer) As they have separate parts the cost is
usually lower, they have better specifications and they don’t give up too much heat. They are
not portable, they need to be hooked up by wiring.

Laptop Computers: Computers that have the keyboard, monitor and processing unit in one
single unit. They have low weight, portability, a processor that does not give too much heat
and good battery consumption. Limited battery life, the keyboard might be awkward.

Netbooks : A computer that can almost fit onto a hand, a smaller version of a laptop. Same
advantages as Laptops, although they are cheaper. They have no optical drives, smaller and
more difficult to write on.

Personal Digital Assistants (PDA’s): Small handed computers which have a touch screen
and have a stylus, they used to be for organization, now they have data loggers, satellite
navigation and word processing. They can be used anywhere and they are very light and
portable.

Smartphones: They use touch screens as the main input. They allow phone calls to be made
but also have a operating system allowing them to run specific applications. They can
send/receive emails, search the Internet, take pictures, etc.

Mainframe Computers : They are very large and powerful computers which can be used for
commercial applications, banking. They have several CPUs, very fast processors, multiple OS
and immense storage capacity. They are very expensive to operate and maintain and can’t be
moved around.

Mika Stupnik 9A ICT Summary

Chapter 2: Input and Output devices

Keyboards : They are used to input text, numbers and instructions into the computer. Most
use QWERTY. Mostly used to input data into apps and typing in commands. They are easy to
use and they are fast.
Numeric Keyboard : Used to enter numbers only (some can input text) They are most
commonly found in ATM’s. Mice : This is a pointing device. A ball beneath this detects movement and moves the cursor
through the monitor. They have two buttons, left-right click. Scroll buttons are common and
can be used to move faster through a document. Touchpad : They are found mainly in Laptops, as a pointing device (replacement of a mice) Its
faster but can be more difficult to operate.

Remote Controls : Used to operate other devices by using infra red signals. DVD, recorders,
TV’s and a lot of other things it can be used for. The signal can be easily blocked but it can be
used from a large distance.

Touch Screens : You can choose an option by simply touching a button on the display, no
need of a pointing device. Useful for self-service, public places (such as airports) Generally
used in PDAs and smart-phones. User friendly and enable fast interaction. Scanners : Used to enter information from a hard copy (paper) into a computer. It scans
through the object with a light and produces images that the computer can read.

Digital Cameras : Photos are stored in a memory and they can be very easy transfer to a
Computer by a Universal Serial Bus (USB) The images can be manipulated. Easier and faster to
upload photos and easy to delete them.
Webcams : They are connected to a computer through a USB port, they don't have any
memory and everything is transmitted directly to the computer. You can chat online, make
web-conferences and to stay in touch. They often have poor quality. Barcode Readers : Used to read information in the form of a Bar Code, they are safer and
easier to use, almost every time they are correct and they are a trusted technology. Microphone: Used in computers for inputting sounds, these are analog, but they use a ADC.

Monitors
Mika Stupnik 9A ICT Summary
CRT Monitor (Cathode Ray Tube): Cathode Ray Tube. Cheap type of monitors, they are
becoming rare as TFT monitors are taking place. They have better viewing angles than TFT
monitors although they are heavier and can run hot.
TFT Monitor (Thin Film Transistor): Thin Film Transistor. Flat Screen Monitor.
Consume much less power, the screen is made up of pixels and they are lightweight. LCD (Liquid Crystal Display): They are similar to TFT monitors. They use tiny pixels to light
up the display, using RGB colors. As they don't output light, they use LED’s as a backlight.
LED (Light Emitting Diode): They give better image contrast and brightness.
Printers
Inkjet Printers: Produce Good Quality, preferring for single pages. They are cheaper,
lightweight and smaller.
Laser Printers: Produce high quality copies, they are very quick.
Dot Matrix Printer: They have poor quality, make a lot of noise and are slow, but are very
cheap in the long run.
Speakers: They can be connected to a computer, they are used for the output of sound. Projectors: They magnify an image from a source (such as DVD) and project it into a larger
screen. This is useful for presentation and education because children can interact with the
the computer. Graph Plotters: A printer that is used to print only graphics, this can be useful as it can print
different variables in different colors and makes a high quality printout.

MICR (Magnetic Ink Character Recognition): It's a system that can read characters printed
in a special ink, commonly used in bank checks. The magnetic ink is magnetized, which gives a
unique code that the computer can later translate to text. It can be used even if it has text
written over it.

OMR (Optical Mark Reader): A device that can read marks written in pen or pencil, used in
questionnaires. It's fast and accurate. OCR (Optical Character Reader): it’s used to scan text and convert it into a readable form.
Mainly used in passports and ID’s. Its not very accurate.