HardwareHardwareHardwareHardware

F451 - AS ComputingF451 - AS ComputingF451 - AS ComputingF451 - AS Computing

Hardware and SoftwareHardware and SoftwareHardware and SoftwareHardware and Software

• Definition Hardware– The physical components

that make up a computer system. Includes all input, output, storage devices

• Definition Software– The computer programs

that tell the computer what to do.

Input & OutputInput & OutputInput & OutputInput & Output

• Definition – Input Device– Hardware used to put data into the computer

• Definition – Output Device– Hardware used to presents data from a

computer

Other input and output devicesOther input and output devicesOther input and output devicesOther input and output devices

Operating a ComputerOperating a ComputerOperating a ComputerOperating a Computer

INPUTINPUT

PROCESSPROCESS

OUTPUOUTPUTT

Data and InformationData and InformationData and InformationData and Information

• Data–Raw Facts and Figures–No structure or context

• Information–Structured, Organised Data–Processed Data

StorageStorageStorageStorage

• Definition – Storage Device– Permanent and Temporary. Hard disk & RAM– Hardware device used to store data. A device

that can receive data and retain it

• Definition – Secondary storage Device– A peripheral/external device used to store

data eg. Hard disk

Types of Secondary StorageTypes of Secondary StorageTypes of Secondary StorageTypes of Secondary Storage

• Hard Disk– Store files, application programs, OS software

• CD-Rom, DVD-Rom– Install software

• CD-RW, DVD-RW– Backup files, Transport Files

• Memory Stick (do not write USB in an exam. You must say memory stick!)– Transport files between computers

HardwareHardwareHardwareHardware

• The term hardware refers to the physical components of the computer.

• Hardware is divided into:– external components (peripherals)– internal components (processing and

storage).

External componentsExternal componentsExternal componentsExternal components

• The term external components refers to the parts that you physically interact with.

• These are also known as peripherals or input/output devices and include the:– keyboard– monitor– printer

SensorsSensorsSensorsSensors

• A sensor is an input device that detects physical quantities.

• Eg. Heat (Thermistor), Light, Sound, Movement

• Used in cars, burglar alarms, fire alarms

• Software must be used to control a sensor and act on the input

ActuatorActuatorActuatorActuator

• Device which can be operated by a computer which produces physical movement eg. electric motor or turning a valve on or off

• Used in large central heating or air conditioning systems

Internal componentsInternal componentsInternal componentsInternal components

• The term internal components refers to the components contained within the casing of the computer.

• They include the:– processor– memory (RAM and ROM)– hard disk.

Types of MemoryTypes of MemoryTypes of MemoryTypes of Memory

Random Access

Memory (RAM)• Immediate access

store (IAS)• It temporary stores

data used by applications that are running.

• The contents are lost when the computer is switched off.

• VolatileVolatile

Random Access

Memory (RAM)• Immediate access

store (IAS)• It temporary stores

data used by applications that are running.

• The contents are lost when the computer is switched off.

• VolatileVolatile

Read Only Memory

(ROM)• ROM is a permanent

storage area which cannot be changed by the user.

• ROM contains the start up software (this makes the PC boot up)

• Non-VolatileNon-Volatile

Read Only Memory

(ROM)• ROM is a permanent

storage area which cannot be changed by the user.

• ROM contains the start up software (this makes the PC boot up)

• Non-VolatileNon-Volatile

RRead ead OOnly nly MMemoryemoryRRead ead OOnly nly MMemoryemory

• Non-Volatile – Contents of memory is not erased when hardware is powered off.

• Contains Start upStart up program

• Start up program is required immediately when power is switched on

RRandom andom AAccess ccess MMemoryemoryRRandom andom AAccess ccess MMemoryemory

• Volatile – Contents of memory is erased when hardware is powered off

• Contains applications software currently being used, OS files

• Allows changes to be made to saved contents

• Fast access to data