Computer Systems

Computer SystemsICT GCSE

The CPU

Central Processing Unit The ‘brain’ of the computer

CPUCPU

Backing Storage

Output Device

Input device

Inside the CPU

Backing Storage

ALU(Arithmetic and Logic

Unit)Immediate Access Store

Input device

Output Device

Control Unit

Typical Computer System

MonitorTower/Base Unit

Keyboard

Mouse

Types of Computer Microcomputer Mainframe

Laptop PC

Desktop PC

Largest type of computer, can

be used by multiple users

at one time

Designed to be used by one

user at a time

Uses PDA (Personal Digital

Assistant): To take the place of a diary/address book, make minor change to documents, check e-mail, on the move

Laptop PC: Any situation where a portable computer is needed

Desktop PC: Any situation where a computer does not need to be moved

Mainframe: Used where vast amounts of processing power and storage is needed, ie banks

PC Types

Networked PC

Connected to a server which it

relies on to operate

Stand alone PC

Will still function fully without any

network connection

Hardware

The hardware is the equipment that makes up a computer system

If you can touch it, it’s hardware! Examples

Input and Output Devices The CPU Storage Devices Media (CDs, DVDs etc)

Software

Programs which run on the computer system (hardware)

For example a MS Office CD is hardware

The program stored on it is software