Zusammenfassung der Ressource
Higher Computing Science
- Languages and environments
- Low-Level
- Corresponds directly to a processor's instruction set
- High-Level
- Written in English
- Procedural
- Uses procedures, functions or sub-routines.
- Visual Basic
- Declarative
- Uses facts, rules and queries to interrogate the knowledge base
- {"item": "bread", "type": "wheat"}
- Object-Orientated
- Uses classes
- Parameters
- Formal - this refers to the variable name
used within the subroutine to hold the
data passed into it, for example, age.
- Actual - this refers to the actual
data that is passed into the
subroutine, for example, 45.
- Global - these
variables can be
used throughout a
program at any
point in the code
- Local - the values stored in
these variables exist within
only one part of the code,
usually within a subroutine
- Methods of Testing
- Dry Run - reading the
code and predicting
what will happen
without actually
running the code.
- Trace Table - lists the
variables in a program
and tracks the values
they store as the code is
executed store as the
code is executed.
- Test Plan
- Normal, Extreme, Exceptional
- Beta Testing - final stage of
testing involving community
- Software Development Methodologies
- Rapid Application Development
- Involves building prototypes
of parts of the software
- Easier to test
- Feedback early on
- Agile Methodologies
- Lack of emphasis on
design and documentation
- Legal
Implications
- Computer Misuse Act
- Unauthorised access
of a computer
- Unauthorised access of a computer
to commit further criminal offences
- Unauthorised
altering of
computer data
- Copyright, Designs
and Patents Act
- Protect time, money and effort
invested by content creators.
- The Communications ACt
- Use other people's Wi-Fi broadband
connections without permission
- Offensive / upsetting
messaging
- Unauthorised interception of
communications (e.g. phone hacking)
- Regulation of Investigatory
Powers Act (RIPA)
- Certain organisations can intercept data, access password protected data
and carry out surveillance for the purposes of crime prevention.
- Protects individuals'
rights to privacy
- The employers must notify
employees if they want to
intercept communications data
- Processor Buses
- Data Bus
- Transfer data between main
memory and the processor.
- Two-way
- Address Bus
- Specify the address of
the memory location
- One-way
- Control Bus
- Read - Reads the contents of a memory location
- Write - Writes an item of data from the
processor into a memory location
- Clock - sends a regular series of pulses
into the processor to synchronise events.
- Reset - stop execution of current
program and then to reboot
- Interrupt - peripheral devices, such as printers,
can send a signal on the interrupt line into the
processor when the require attention. This
causes the processor to deal with the
interrupting device.