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