CXC Information Technology Section One Revision Does not include binary arithmetic & Information Processing (Unit 5) What youll need Past paper questions:

CXC Information CXC Information Technology Technology Section One RevisionDoes not include binary arithmetic & Information Processing (Unit 5)

What you’ll need

•Past paper questions: 2010 – 2014•Mr. Alleyne website: www.it.anthonyalleyne.com•Constant revision is critical

Unit One - Basic Unit One - Basic componentscomponentsCPU: ALU and control unitPrimary Storage: RAM, ROM

etc.Secondary Storage: diskettes,

CDs etc.Input devices: mouse etc.Output devices: monitor etc.

Primary MemoryPrimary MemoryBistable device: Only has two

states, on and off (1 and 0)Read Only Memory: boots up the

PC. Non volatileRandom Access Memory: used

while PC is working. Volatile (needs power)

PROM: Programmable ROMEPROM: Erasable programmable

ROM

Secondary memorySecondary memoryMagnetic tape: uses sequential

access. Good for backing upFloppy disk: uses direct access. Hard disk (drive): fixed or moving

headOptical disk: CD / DVDMemory cards: Cameras, phones

etc.USB (flash) drives: Portable

USB – Universal Serial Bus

Other termsOther termsTrack: Circles around disk’s surfaceSector: One part of the circleCluster: Adjacent sectorsBuffer: extra memory space when

copying dataSequential access: data stored in

the order it’s receivedDirect access: data stored in any

orderHard drive interfaces

◦SCSI, IDE, SATA and USB (external hard drive)

Units of storageUnits of storageBit: smallest unit of storageByte: 8 bitsKilobyte: 1024 bytesMegabyte: 1024 kilobytesGigabyte: 1024 megabytesTerabyte: 1024 gigabytesWord / Word size: size of a single

instruction. (i.e. How much data a CPU can handle at one time.)

Input DevicesInput DevicesMouseKeyboardJoystickMicrophoneScannerWebcamGraphics

pad/tabletBarcode readerWebcam

Light PenTouch terminalOptical Mark

ReaderOptical Character

Reader Magnetic Ink

Character ReaderBiometric SystemSensor

Output DevicesOutput Devices

MonitorProjectorSpeakersHeadphone

sPrintersPlotterMicrofilm

Output termsOutput termsResolutionPixelQualityHard copySoft copyHuman readableMachine readable

PrintersPrintersDot matrixLineDaisy Wheel

InkjetLaserjetThermal

IMPACT

NON -IMPACT

SoftwareSoftwareApplication Software

◦Custom written (for one purpose only)◦Specialised (for a group/category:

ACCPAC)◦General purpose (for everyone: Word, etc.)◦Integrated (more than one programme:

Office)

Systems software◦Operating system (Windows, Linux, Unix,

OSX)

Operating System Operating System functionsfunctionsFile managementResource management User managementInput – Output managementSecurity Memory Maintenance (defrag, format,

cleanup)

Interfaces and termsInterfaces and termsCommand line interface: command

must be typed. Difficult to use

Menu driven interface: command selected from a menu: Options limited

Graphical user interface: Like Windows

Pop up and pull down menusIconsTaskbar

Processing – how does the Processing – how does the CPU do it?CPU do it?

Batch: collect in groups, then

process

Online: processed once CPU is on

Real-time: processed immediately

Timesharing: processes many

jobs, a piece at a time

Computer specificationsComputer specificationsCPU: 2.4 Ghz 64-bit Pentium 4Hard drive: 1TB 7200 rpm SATAMemory: 1GB DDR-RAMOS: Windows 7 Home editionPorts: 6 USB ports, 1 firewire portOptical drive: 54X DVD/RW driveSlots: 1 AGP slotVideo: Radeon 64MB video card

Networks Networks Local area network: small areaMetropolitan area network:

medium sized areaWide area network: large area

(e.g. continent)

Internet: public Intranet: privateExtranet: private with some outside

access

Networking termsNetworking termsCoaxial cable

(antenna)Twisted pair

(phone/ADSL)Fiber optic cable

(light)

InfraredBluetoothWi-fiHotspot

Bandwidth (how much)Speed / Rate (how fast)

Voiceband (phone line)Broadband (ADSL)Wireless

Simplex (1 way only)Half duplex (1 way at a

time)Full duplex (both ways)

The internet & termsThe internet & termsWWWWeb page, site,

browserHTTP, HTMLFTPURLUpload vs.

downloadSearch engineIRC

E-mailBulletin boardNewsgroupBloggingE-commerceE- learningVoIP

Data SecurityData SecurityPasswordsEncryptionAccess

restrictionsFirewallsVirus protectionBackup &

recoveryArchiving

LocksSecurity guardsFireproof

cabinetsWaterproof

cabinetsBiometric

systems

Data misuseData misuseInformation TheftCopyright infringementEavesdroppingInvasion of privacyComputer fraudPropaganda

Current trendsCurrent trendsExpert SystemsComputer Aided Manufacturing

(and Design)TeleconferencingTelemarketingRobotsLaser technology

JobsJobs

TechnicianSoftware / computer engineerDatabase / Network

administratorFile librarianWeb master / web developerSoftware trainer (teacher)Systems analystProgrammers

Information ProcessingInformation Processing

Anyone can use computers for the following

CommunicationResearchPublishing and PrintingStorageData processing and analysis