OCR GCSE Computing

Annotations:

• How to investigate and discuss computer science technologies, considering ethical, legal https://youtu.be/yOZnzAoywkE?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
• Legislation https://youtu.be/-bgTNETy51U?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
• Privacy issues https://youtu.be/0wia_H4Y7Dc?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
• Cultural implications https://youtu.be/bRF-4fB5dIg?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
• How key stakeholders are affected by technology https://youtu.be/zibnWKPey5g?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
• Environmental impact of computer science https://youtu.be/4nOsXv4RVFY?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-

1. Programming
   1. Iteration

      Annotations:

      • for x in range(10): print(x)
   2. Sequence

      Annotations:

      • 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
   3. Selection

      Annotations:

      • if else if else
   4. High level languages
      1. Python
      2. Java
      3. C; C++
      4. Visual Basic
      5. Closer to human language. Easier for humans to read and understand
   5. Low level language
      1. Machine code
      2. Assembly language
2. Networks

   Annotations:

   • 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-
   1. Topology

      Annotations:

      • Star and Mesh networks https://youtu.be/Owj3cxp13bQ?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
      1. Ring
      2. Star
      3. Bus
   2. Hardware

      Annotations:

      • 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-
      1. Router
      2. Hub
      3. Switch
      4. Bridge
      5. Fibre
      6. Coaxial
      7. Terminator
   3. LAN
   4. WAN
   5. Bandwidth
   6. Client-server
   7. Peer-to-peer
   8. The Internet

      Annotations:

      • The Internet https://youtu.be/Sa2y9JngSnM?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   9. Virtual networks

      Annotations:

      • https://youtu.be/8F5Y4TwAmfc?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
3. Computer hardware

   Annotations:

   • https://youtu.be/rxSWH6hIO5k?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
   1. Input devices

      Annotations:

      • Input and Output devices https://youtu.be/oUSFS2ROMnU?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
      1. Keyboard
         1. Mouse
            1. Scanner
               1. Touch screen
                  1. Microphone
      2. Accessibility
         1. Braille keyboard
   2. Output devices
      1. Monitor
         1. Speakers
            1. Printer
               1. Laser
               2. Ink jet
               3. Plotter
               4. Projector
   3. Processing devices
      1. CPU central processing unit

         Annotations:

         • https://youtu.be/6UVMCIQ6nFI?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
         1. Cache
         2. Arithmetic Logic Unit
         3. Registers
         4. Cores
         5. Multi tasking
         6. Clock speed
         7. Address bus
         8. Data bus
         9. Von Neumann Architecture

            Annotations:

            • https://youtu.be/KR2ejxGq464?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
         10. Performance

             Annotations:

             • https://youtu.be/hGkyon3c7rQ?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
      2. RAM (Volatile) / ROM (non-volatile)

         Annotations:

         • https://youtu.be/PkcOYz7yLM4?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
         • https://youtu.be/N2dukz_5Skg?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
      3. Graphics card
      4. Sound card
      5. Motherboard
   4. Secondary Storage devices

      Annotations:

      • 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-
      1. Magnetic
         1. Hard disk drive
         2. Floppy disk
         3. Magnetic tape
      2. Optical
         1. CD-ROM; CD-R; CD-RW; CD-RAM
         2. DVD - Digital Versatile Disk
      3. Flash Memory

         Annotations:

         • https://youtu.be/naNdLozCp1Q?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
         1. SD Cards
         2. Solid State Drives
         3. BIOS
      4. Data capacity

         Annotations:

         • https://youtu.be/OEcRsaJVe1M?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   5. Embedded systems

      Annotations:

      • https://youtu.be/AgGOH1vSTyk?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
   6. Virtual memory

      Annotations:

      • https://youtu.be/xziqSwXKjRY?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
4. Computing units

   Annotations:

   • https://youtu.be/eG6xdjqcHOs?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
   1. Binary

      Annotations:

      • https://youtu.be/eG6xdjqcHOs?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
      • Why data is represented in binary https://youtu.be/wF4wzQNB_G8?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
      1. One bit has 2 different values
      2. 0 1
      3. Base 2
   2. Denary

      Annotations:

      • https://youtu.be/eG6xdjqcHOs?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
      1. Base 10
      2. How we (humans) count
      3. 0 1 2 3 4 5 6 7 8 9
      4. 10 different values 0-9
   3. Hexadecimal

      Annotations:

      • https://youtu.be/Ft7IdQYu0Zk?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
      1. One bit has 16 different values
      2. 0 1 2 3 4 5 6 7 8 9 A B C D E F
         1. 0-15
      3. Base 16
   4. 1111 - nibble
   5. 1 - bit
   6. 1111 1111 - byte
   7. Character sets

      Annotations:

      • https://youtu.be/_FWd-8xr8rc?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
      1. ASCII
      2. Unicode
5. Software

   Annotations:

   • https://youtu.be/LfiSAhno3NI?list=PL04uZ7242_M5n3zzAhcX-eslHud2Lyycd
   1. Operating systems

      Annotations:

      • 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-
      1. Memory management
      2. File systems
      3. Networking
      4. User management
      5. Input and output
      6. Interrupt handling
      7. Kernel
         1. Deals with low level operations such as memory management
      8. multi-tasking
         1. Allow more than one application to run at the same time, e.g listening to music while writing an essay in Word
   2. Utility programs

      Annotations:

      • Utility system software https://youtu.be/suqAIPF2VKs?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
      1. Antivirus
      2. Anti spyware
      3. Firewall
      4. Backup software
      5. Clipboard
      6. Cryptographic tools
      7. Compression tools
      8. Disk cleaner
      9. Disk defragmenter
      10. Disk partitioning and formatting tools
   3. Development models
      1. Custom written/bespoke
         1. For specific purpose
         2. Expensive
         3. Not readily available
      2. Off the shelf
         1. Ready made
         2. Does the job
         3. May include features you don't need or be missing something you do
      3. Proprietary
         1. Source code not released
         2. Remains the property of the organisation
      4. Open source
         1. Free
         2. Code can be modified
   4. Open source vs proprietary

      Annotations:

      • https://youtu.be/wq2GY4tXjQM?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
6. Logic Gates

   Annotations:

   • 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-
   1. AND
   2. OR
   3. NOT
   4. Truth tables

      Annotations:

      • Truth tables https://youtu.be/YtDJRYdnEvw?list=PLCiOXwirraUAvkTPDWeeSqAKty3LAG37-
7. Databases
   1. Persistent and organised store of data
   2. File
   3. Relation (table)
   4. Tuple (record/row)
   5. Attribute (field)
   6. Flat-file database
      1. All data stored in one table
      2. Data is duplicated
         1. Data redundancy
         2. Possibility of errors
      3. No structural information
   7. Relational database
      1. Entities
         1. One thing
            1. e.g. student
            2. e.g. course
            3. e.g. car
      2. Primary key
         1. An attribute that contains data unique to that relation (table)
         2. Provides the link to another relation
      3. Foreign key
         1. The link to another relation
         2. A foreign key is the primary key in another table
   8. Data types
      1. Real/float
      2. String/text
      3. Integer
      4. Boolean
      5. Date/time
   9. Validation

      Annotations:

      • 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

   Annotations:

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

   Annotations:

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

    Annotations:

    • 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-
    1. Malware
    2. Trolans
    3. Phishing
    4. Worms
11. Youtube playlists

    Annotations:

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