Data representation

• Representation of positive numbers in binary  including place values and range up to and including 32 bits
• Conversion from binary  to  decimal and vice versa
• Description of the representation of negative numbers  using two’s complement using examples  of up to 8 bit  numbers
• Description of the relationship between the number of bits assigned to the mantissa/exponent and the range and  precision of floating point  numbers
• Conversion to  and from  bit, byte, Kilobyte, Megabyte, Gigabyte, Terabyte. (Kb, Mb, Gb,  T b )
• Description of  Unicode and its advantages over ASCII
• Description of the bit map  method of graphic representation using  examples of colour/grey scale bit maps
• Description of  the relationship of  bit depth to  the number of colours using exam ples up to and including  24 bit depth  (true colour)
• Description of the vector graphics  method of graphic representation
• Description of  the relative advantages and disadvantages of bit mapped and  vector graphics
• Description of  the relationship between the bit depth  and file size
• Explanation of  the need for data compression using  the storage of bitmap graphic files, as examples

Computer structure

• Detailed description of the purpose of the ALU and control unit
• Description of the purposes of registers:
  • to hold data being processed
  • instructions being executed
  • addresses to be accessed
• Description of the function of the data bus and the address bus
• Description of the read, write and timing functions of the control lines
• Identification of other control lines, including reset and interrupt lines
• Simple description, referring to the appropriate buses and control lines, of the steps in the fetch-execute cycle
• Description of the following elements of computer memory : registers, cache, main  memory, backing storage
• Distinction between the above elements of memory according to function and speed of access
• The concept of addressability
• Description and evaluation of the following measures  of performance:
  • clock speed
  • MIPS
  • FLOPS
  • application based tests
• Description of the effect the following factors have on system performance:
  • data bus width
  • use of cache memory
  • rate of data transfer to and from peripherals
• Description of current trends in computer hardware, including
  • increasing clock speeds
  • increasing memory
  • backing storage capacity

Peripherals

• Description of  the use and advantages of buffers and spooling
• Description of a suitable selection of hardware,  including peripherals, to support typical tasks including
  • production  of a  multimedia catalogue
  • setting up a LAN in a school
  • development of a school website
• Justification of the hardware selected in terms of  appropriate characteristics including
  • resolution
  • capacity
  • speed
  • cost
  • compatibility
• Description of the features,  uses and advantages  of solid state storage devices including flash cards
• Description of the development trends in backing storage devices
• Description of the following functions of an interface:
  • buffering
  • data format conversion (serial to parallel)
  • data format conversion (analogue to  digital)
  • voltage  conversion
  • protocol  conversion
  • handling of status signals
• Distinction between parallel and serial interfaces
• Description and explanation of the current trends towards increasing  interface speeds and wireless communication between peripherals and CPU

Networking

• Comparison of LANs, WANs, Intranet and Internet  work in terms  of
  • transmission media
  • bandwidth
  • geographical spread
  • functions
• Distinction between a  main frame with terminals and  a network of computers
• Descriptive comparison of peer-to-peer networks and client server  networks
• Description of  the functions of file, print and web servers
• Description of  a node and  a channel
• Description of  bus, star, ring  and mesh topologies using the terms node and channel
• Description of the consequences for each of the above topologies of node and channel failure
• Simple description  of the functions  and  uses of a hub, switch and router
• Identification of the need for a network interface card (NIC)
• Description and explanation of the trends towards higher bandwidth and wireless communications
• Description of the following technical reasons  for the increasingly  widespread use of networks:
  • advances in computer hardware
  • including processors
  • main memory  capacity
  • backing  storage
  • data transfer rates
  • improved network related software, including
    • browsers
    • network operating systems
• Description of the misuse of networks for the following illegal purposes:
  • breaching copyright
  • hacking
  • planting viruses
• Description of  the application of the following to the misuse of networks
  • the Computer Misuse Act
  • the Copy right  Designs and Patents Act
  • the Data Protection Act

Computer software

• Description of the function of a bootstrap loader
• Description and exemplification of the main functions of a single user operating system :
  • interpreting users commands,
  • file management,
  • memory  management,
  • input/output management,
  • resource allocation,
  • managing processes
• Definition of a utility  program
• Description of utility  programs including:
  • virus checker
  • disk editor
  • defragmenter
• Description of the standard file formats for graphics files:
  • jpeg
  • gif
  • TIFF
• Description of  a suitable selection of software to support typical tasks including:
  • production of  a multimedia catalogue
  • setting up a LAN in a school
  • development of a school website
• Description and exemplification of software compatibility  issues
  • including memory and storage requirements
  • OS compatibility
• Classification of viruses by type of file infected:
  • file virus
  • boot  sector virus
  • macro virus
• Description of  the following  virus code actions :
  • replication
  • camouflage
  • watching
  • delivery
• Distinction between
  • a virus
  • a worm
  • a Trojan horse
• Description of anti-virus software detection techniques:
  • use of checksum
  • searching for virus signature
  • heuristic detection
  • memory  resident monitoring