IGCSE ICT Chapter 1

systems software

programs that allow the hardware to run properly e.g. operating systems

applications software

programs that allow the users to do specific task e.g. spreadsheet

software

programs that control the computer system

CLI (Command Line Interface)

requires user to type in instructions in order to choose options from menus, open software etc.

PDA (Personal Digital Assistants)

small handheld computers that usually come with a touch screen that is activated using a stylus

Advantages of PC

spare parts and connections are standardized- low costs desktops have better specifications large casing allows good dissipation of heat build-up

Advantages of PDAs

used anywhere because of its small size very lightweight and more portable than laptops

Advantages of Laptops

very portable since everything is under one single unit and can also be linked into any multimedia system no trailing of wires- less clutter takes full advantages of WiFi low weight

Advantages of Netbook

very portable since everything is under one single unit and can also be linked into any multimedia system no trailing of wires- less clutter takes full advantages of WiFi low weight cheaper to purchase

Mainframe computers

very powerful and large computer systems.

secondary storage devices

way of storing information from the computer system i.e, DVD, hard drive

Uses of mainframe computers

USED IN BANKING AND INSURANCE WHERE HUGE AMOUNTS OF DATA NEEDED TO BE PROCESSED EACH DAY: several CPUS fast processor speeds support multiple operating systems huge amounts of storage capacity

Netbook

a computer that can almost fit into a hand and is a smaller version of laptop

GUI (Graphic User Interface)

allows the user to interact with a computer (or any other device) using pictures or symbols (icons)

general tasks of operating systems

controlling the operation of input, output and backing storage devices supervising the load, running and storage of applications programs dealing with error that occur in applications program maintaining security of the whole computer system maintaining a computer log allowing communications between user and the computer system (user interface)

output devices

devices that output information outside the computer systems i.e. monitor, printer

input devices

devices that put information inside the computer systems i.e. keyboard, mouse

Disadvantages of PDAs

difficult to enter text quickly have limited capabilities due to software and operating systems used

Disadvantages of Netbooks

don't have optical drives keyboards are too small- only 80 % size of laptop keybaords lack of some of features found in larger laptops because of its constraint- cheaper to purchase

Advantages of Mainframe computers

due to features above, they can be used to do very large tasks used in time-sharing systems capable of very large number crunches so can deal with complex mathematical functions

operating systems

enable users to communicate with computer systems

PC/desktop computers

general purpose computers made up of separate monitor, keyboard, mouse, and processor unit

Laptop Computers

monitor, keyboard, pointing device and processor are all in one single unit.

Disadvantages of Mainframe computers

need to be permanently stored in large room- not portable expensive to operate and maintain

Disadvantages of PC

not portable components need to be hooked up by wiring which can be complex and clutter up space necessary to cop files when doing work at different place other than where desktop is situated

hardware

physical components that make up a computer system i.e. keyboard, mouse, monitor, processor, circuit board and so on

Disadvantages of Laptops

portable, so easy to steal limited battery life and may need to carry heaving adapter keyboards/pointing devices maybe awkward to use heat dissipation is more difficult