OCR GCSE Computing

OCR GCSE Computing

1. Programming

   • Iteration
     • for x in range(10): print(x)
   • Sequence
     • Turn red light on Wait 10 seconds Turn amber light on Wait 3 seconds Turn red and amber light off Turn green light on Carry out instructions one after the other
   • Selection
     • if else if else
   • High level languages
     • Python
     • Java
     • C; C++
     • Visual Basic
     • Closer to human language. Easier for humans to read and understand
   • Low level language
     • Machine code
     • Assembly language

2. Networks

   • Types of networks https://youtu.be/yjWR0OP2SzY?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Factors that affect performance of a network https://youtu.be/vTP6mdCw1uE?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Client server and peer to peer  https://youtu.be/B3jRl98Ymrw?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Layers https://youtu.be/_CXFFqPbOXU?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Packet Switching https://youtu.be/lfYl8SohrCo?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Topology
     • Star and Mesh networks https://youtu.be/Owj3cxp13bQ?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Ring
     • Star
     • Bus
   • Hardware
     • Hardware to connect to a network https://youtu.be/PPr9Oa_jj1Q?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • WiFi https://youtu.be/Svm06j2_x5w?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Ethernet https://youtu.be/PzVZpXGuI1I?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Protocols https://youtu.be/3Y2aQPwY0fo?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Router
     • Hub
     • Switch
     • Bridge
     • Fibre
     • Coaxial
     • Terminator
   • LAN
   • WAN
   • Bandwidth
   • Client-server
   • Peer-to-peer
   • The Internet
     • The Internet https://youtu.be/Sa2y9JngSnM?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Virtual networks
     • https://youtu.be/8F5Y4TwAmfc?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-

3. Computer hardware

   • https://youtu.be/rxSWH6hIO5k?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
   • Input devices
     • Input and Output devices https://youtu.be/oUSFS2ROMnU?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
     • Keyboard
       • Mouse
         • Scanner
           • Touch screen
             • Microphone
     • Accessibility
       • Braille keyboard
   • Output devices
     • Monitor
       • Speakers
         • Printer
           • Laser
           • Ink jet
           • Plotter
           • Projector
   • Processing devices
     • CPU central processing unit
       • https://youtu.be/6UVMCIQ6nFI?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
       • Cache
       • Arithmetic Logic Unit
       • Registers
       • Cores
       • Multi tasking
       • Clock speed
       • Address bus
       • Data bus
       • Von Neumann Architecture
         • https://youtu.be/KR2ejxGq464?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
       • Performance
         • https://youtu.be/hGkyon3c7rQ?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • RAM (Volatile) / ROM (non-volatile)
       • https://youtu.be/PkcOYz7yLM4?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
       • https://youtu.be/N2dukz_5Skg?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Graphics card
     • Sound card
     • Motherboard
   • Secondary Storage devices
     • https://youtu.be/-uAbk2UgzIg?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
     • https://youtu.be/nE8g77ftMvU?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Common Types of Storage https://youtu.be/2vJ0NfG1G_s?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Suitable storage devices for a given purpose https://youtu.be/MmyB4d8oGq8?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Magnetic
       • Hard disk drive
       • Floppy disk
       • Magnetic tape
     • Optical
       • CD-ROM; CD-R; CD-RW; CD-RAM
       • DVD - Digital Versatile Disk
     • Flash Memory
       • https://youtu.be/naNdLozCp1Q?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
       • SD Cards
       • Solid State Drives
       • BIOS
     • Data capacity
       • https://youtu.be/OEcRsaJVe1M?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Embedded systems
     • https://youtu.be/AgGOH1vSTyk?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Virtual memory
     • https://youtu.be/xziqSwXKjRY?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-

4. Computing units

   • https://youtu.be/eG6xdjqcHOs?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
   • Binary
     • https://youtu.be/eG6xdjqcHOs?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
     • Why data is represented in binary https://youtu.be/wF4wzQNB_G8?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • One bit has 2 different values
     • 0 1
     • Base 2
   • Denary
     • https://youtu.be/eG6xdjqcHOs?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
     • Base 10
     • How we (humans) count
     • 0 1 2 3 4 5 6 7 8 9
     • 10 different values 0-9
   • Hexadecimal
     • https://youtu.be/Ft7IdQYu0Zk?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
     • One bit has 16 different values
     • 0 1 2 3 4 5 6 7 8 9 A B C D E F
       • 0-15
     • Base 16
   • 1111 - nibble
   • 1 - bit
   • 1111 1111 - byte
   • Character sets
     • https://youtu.be/_FWd-8xr8rc?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
     • ASCII
     • Unicode

5. Software

   • https://youtu.be/LfiSAhno3NI?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
   • Operating systems
     • Purpose and function of system software https://youtu.be/mvpc9zst-y4?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Operating systems part 1 https://youtu.be/m574Z-ebSaY?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Operating systems part 2 https://youtu.be/4IJZY-4cjhc?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Memory management
     • File systems
     • Networking
     • User management
     • Input and output
     • Interrupt handling
     • Kernel
       • Deals with low level operations such as memory management
     • multi-tasking
       • Allow more than one application to run at the same time, e.g listening to music while writing an essay in Word
   • Utility programs
     • Utility system software https://youtu.be/suqAIPF2VKs?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
     • Antivirus
     • Anti spyware
     • Firewall
     • Backup software
     • Clipboard
     • Cryptographic tools
     • Compression tools
     • Disk cleaner
     • Disk defragmenter
     • Disk partitioning and formatting tools
   • Development models
     • Custom written/bespoke
       • For specific purpose
       • Expensive
       • Not readily available
     • Off the shelf
       • Ready made
       • Does the job
       • May include features you don't need or be missing something you do
     • Proprietary
       • Source code not released
       • Remains the property of the organisation
     • Open source
       • Free
       • Code can be modified
   • Open source vs proprietary
     • https://youtu.be/wq2GY4tXjQM?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-

6. Logic Gates

   • https://youtu.be/nBUNxuPkPts?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd https://youtu.be/56W-SBpdy9o?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
   • Simple logic diagrams https://youtu.be/eRW0cpApegk?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • Computing related maths https://youtu.be/XImmzjrMj6A?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   • AND
   • OR
   • NOT
   • Truth tables
     • Truth tables https://youtu.be/YtDJRYdnEvw?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-

7. Databases

   • Persistent and organised store of data
   • File
   • Relation (table)
   • Tuple (record/row)
   • Attribute (field)
   • Flat-file database
     • All data stored in one table
     • Data is duplicated
       • Data redundancy
       • Possibility of errors
     • No structural information
   • Relational database
     • Entities
       • One thing
         • e.g. student
         • e.g. course
         • e.g. car
     • Primary key
       • An attribute that contains data unique to that relation (table)
       • Provides the link to another relation
     • Foreign key
       • The link to another relation
       • A foreign key is the primary key in another table
   • Data types
     • Real/float
     • String/text
     • Integer
     • Boolean
     • Date/time
   • Validation
     • Make sure that the data entered is in the correct format
     • Range check - make sure the value entered is between two values - e.g 0-100
     • Presence check - make sure that something has been entered - e.g. Surname
     • Format check - to ensure it is entered in the right format, for example a postcode could be letter, letter, number number space number letter letter (LL00 0LL)
     • Lookup - the value must exist in a predefined list - e.g. Title (Mr, Mrs, Miss, Ms, Dr, Prof, Master Etc...)

8. Images

   • https://youtu.be/OooQh_4-WYU?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd

9. Sound

   • https://youtu.be/p7GLbx0Yde4?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd

10. System security

    • Forms of attack https://youtu.be/M6hhP0PcJbk?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
    • Threats posed to networks https://youtu.be/9zC4FJk-YFg?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
    • Identifying and preventing vulnerabilities https://youtu.be/bNRZb2tPcR8?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
    • Malware
    • Trolans
    • Phishing
    • Worms

11. Youtube playlists

    • Craigndave - excellent and very clear https://www.youtube.com/playlist?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
    • Somerevision https://www.youtube.com/playlist?list=PLCE06F413DAD96BBF
    • Axsied (link available on your Smarthomework - cannot share here due to copyright)

12. Legislation

    • Computer misuse act
      • Hacking
      • Stealing data
      • Modifying data
    • Copyright, designs and patents act
      • Copying movies, games, music etc
      • Stealing ideas
      • Illegal streaming of movies online
    • Data protection act
      • Only keep data as long as required
      • Keep data safe and secure
      • Do not pass data on to other people or organisations
    • Regulation of investigatory powers act
      • Organisations can request access to private data in certain circumstance
        • e.g. Suspect of terrorism