Tag view
84 related notes
To put it simply, enum erable classes in Java are weird. Writing vs. Compiled Enumerable classes get transformed from being an enum type into a class type final, extends Enum at th...
A device driver is a piece of software that communicates between the OS and external I/O devices. They can perform specific operations and the I/O devices, i.e., printing for print...
Dry Run A dry run is the manual execution of a program using sample input values. The programmer follows the program line by line and records the values of variables in a trace tab...
Black box Testing Black box testing is solely concerned with the functionality of a program. It is not concerned about the internal functionality, only if it takes in A and returns...
Suitable Test Data Suitable test data is used to check that a program behaves correctly for different types of input. It helps identify errors and confirm the program accepts valid...
Trace Tables Trace tables are used to test and understand how an algorithm works. They help track how variables change while a program executes. Each variable in the program has it...
User feedback is an important part of software development. Developers should regularly involve users during development rather than only at the beginning and end. Benefits of regu...
Why? Positives Testing software on different types of hardware in an easier way. Testing malware software disposable. They do not affect hardware. Allows for cross platform use/tes...
The phases of software development are known as the Software Development Lifecycle SDLC . The arrangement of the phases are known as a software development methodology , Phases Fea...
Input Device Any device that allows you to pass information from the outside world into a computer system. Output Device Any device that can take data stored in digital form and co...
RAM Random Access Memory Memory used for the temporary storage of instructions and data. It holds information being executed by the processor. Volatile. Faster than disc. ROM Read...
Drive The device that reads and writes data from secondary storage. Media What the data is actually stored on. Magnetic Storage Examples: Hard disk drive, tape Magnetic storage use...
A multicore processor is a single chip composed of two or more independent processing units. A CMP with two cores is commonly referred to as a dual core processor. A CMP with four...
RISC reduced instruction set computer. CISC complex instruction set computer. RISC CPUs/computers are typically much smaller than CISC CPUs/computers. CISC reduces the number of li...
System bus is a generic term for any buses. Von Neumann Covered in Structure and Function of the CPU. Shared memory space for instructions and data Instructions and data are stored...
A lot of information is sourced from Graphs Computer Science A graph is a set of nodes/vertices connected by edges/pointers. There are three types of graphs: Directed Graph: The ed...
See: Thinking Concurrently Fetch The program counter PC passes the address of the current instruction to the memory address register MAR It then increments to hold the address of t...
info This is a set of cut down notes based on Advanced Notes 1.5.1 Computing related legislation OCR Computer Science A level. The Data Protection Act 1998 info This has been super...
1. 2.
This is a log of all lesson starters. info I avoided keeping track of these throughout Year 12 despite frequently containing useful information.
Quite a lot of operations are done for 'preparedness'. Memory Data Register MDR also known as the Memory Buffer Register MBR . Communicates with the RAM over the data bus , sets an...
Heuristics is the action of not creating a perfect solution to a problem at the expensive of computational power and time . It is a "good enough" solution. NOTE A uses a heuristic...
Abstraction. The idea of filtering out/hiding unnecessary information to make a problem easier to understand. Simplifying the problem. Reasons: Making it easier to code Making the...
The idea of making sure a program can do multiple processes at one time . Parallel processing literal parallel, things actually happening at the same time . Multiple processors/cor...
Decomposition. The idea of breaking down a larger problem into smaller, more digestible, sub problems that can be completed individually in order to make a problem easier to unders...
Data mining is the action of pattern finding on a large data set which cannot normally be easily found by humans. Only works on large data sets. Needs server farms and therefore lo...
Create Table Creates a table within a database. Reference You can include a primary key reference by doing: Example
%% TODO Find more about this one %% Good and Provides much more detailed and smart social applications Data can be used to target adverts towards you Gives companies insight into w...
A collection of items of the same type stored continuously in memory, maintaining order. Traits | Homogenous? | Yes | | | | | Static/dynamic? | Static | | Mutable? | Yes | Example...
There is a large cross over between automated decision making and artificial intelligence, therefore they are merged together in a single document. info Definition of AI artificial...
Moves through the list until the wanted item is found using divide and conquer . Implementation Advantages Fast on larger datasets O 1 best case scenario, O log n worst case scenar...
Iterates through the list, swapping the items if valid i.e., ascending and the first number is larger . This must be performed multiple times to fully sort a list, to decide whethe...
Good Enables citizens of a 'trapped' country to speak out Provides a tunnel voice to those who need it i.e., shouting through a tunnel someone might hear it and listen Exercises th...
info This only contains required commands by OCR. Useful commands beyond the OCR specification can be found in Additional Commands. Select Fetches data from a given set. Order By S...
Note: This is to the specification only . Lexical Analysis Lexer Lexenes Tokens Token Stream Symbol Table Lexens Lexens are an intermediary stage between the source and tokens. It...
Purpose The purpose of compression is to: reduce the size of files reduce download times reduce storage requirements make best use of bandwidth in relation to prior point given the...
Good Assistance some people may find it harder to work without computers Typing rather than handwriting Effectiveness more productivity during work hours Typing enables people to w...
CRUD is the acronym for: C reate R ead U pdate D elete All relational databases support these operations and can be directly mapped to SQL statements. | Word | Commands | Wikilinks...
CSS c ascading s tyle s heet is a style sheet language used to outline the styling of a HTML webpage. Reference A CSS style sheet can be referenced/included in a webpage in either...
Data integrity: the process of maintaining the consistency of the database. Being able to guarantee data integrity is vital to the database. Tutor Definition: Data integrity is the...
Example Application: Text Composed of a dictionary and message. Common sequences of characters may be handled as, i.e., words are replaced with dictionary references. Implementatio...
Making, running, disposal Good Can help analyse issues with the Earth Replaces travel now online Reduction has led to lesser energy consumption Global collaboration Sensors Tsunami...
Modem Transforms digital information into analogue signals which can be transmitted through wires Translates incoming analogue signals into digital information Modulates and demodu...
Comes in Paper 2, not paper 1. A hash table is a form of key, value table with the goal to immediately find an item. A hashing function is used to calculate the position of an item...
Iterates through the list, starting at the second item and then iterating backwards and inserting before the last valid i.e. larger if ascending number. Implementation Advantages F...
Java has two different forms of switches: tableswitch, table with keys and labels lookupswitch, table with only labels tableswitch Speed: O 1 tableswitch utilises only labels. It t...
A primary key is a key that is uniquely identifiable to each row within a database. It cannot be null and may be composed of multiple foreign keys. A foreign key is a key that refe...
Layers are an abstract form of model representing the transportation of requests. An example of this is the OSI model and TCP/IP. Each layer is completely independent and has one s...
Good Accessibility Web standards were developed to ensure the web is largely accessible Colour paradigms can be used to associate colours with a brand Makes the brand more memorabl...
Open source Code is open to people, frequently under a license outlining what they are able to do, what they are not able to do. Closed source Code is not open to people and under...
Iterates through the list until the wanted item is found. Implementation Advantages Easy to program Fast on small datasets O 1 space Disadvantages O n slow on large datasets
A collection of nodes composed of: the item piece of data the pointer to the next node or null pointer Big O Notation: O n Implementation %% TODO: Include insertion and other metho...
An abstract data type representing a sequence of items. Traits | Homogenous? | No | | | | | Static/dynamic? | Dynamic | | Mutable? | Yes | Example Usage Pseudocode not explicitly i...
Little Man Computing is an instruction set for assembly language, composed of 12 instructions, using Memory Addressing. Example Adding two numbers. Labels A label is a reference to...
Direct References the given memory location which contains the wanted value. Immediate References the given value itself. Note: limited in bit size due to mnemonic structure: Indir...
A sort composed of breaking down an array into minimal sets 2, if remainder then 3 , then sorting and popping the smallest number when joining. Implementation Advantages Fast on la...
%% TODO Find more about this one %% Good Security and crime prevention Reduction in criminality More control over criminality Potential prediction May display signs of anything , i...
info Scheduling cheatsheat. Scheduling is used by operating systems to support the illusion of running multiple processes simultaneously. Scheduling First Come First Serve FCFS Non...
Diagram
Need for Security To only permit authorised users to access what they need To prevent unauthorised access To minimise potential damage from unauthorised access Firewall Controls ac...
Code Quality Improving general code quality helps prevent vulnerabilities. Guarding against attacks Buffer overflow SQL injection Input validation Additional security functionality...
Mal icious Soft ware Malware Unwanted Dangerous Worm Standalone program, does not need to be run Exploit vulnerabilities in the destination to spread automatically Virus Embeds its...
A network is two or more computers connected together. The largest network is the internet. Advantages Users can share files Users can share peripherals and connections to other ne...
WARNING This document has AI generated images. Normalisation is a process used to produce the most optimal design for a database. It requires that tables should be organised as so...
Resource management/multi tasking Multi tasking is when you have more than one program open and running simultaneously. The processor allocates a thin slice of time to each process...
Circuit Switching Basis for traditional telephone networks Creates a temporary and dedicated link of fixed bandwidth between the source and destination Guarantees the quality of tr...
Calculation The PageRank formula refines itself over time, considering current page scores. Factors In bound links Main factor, most effectual in PageRank Frequency and magnitude o...
Similarities 1. Both allow programs to run despite insufficient memory 2. Pages and segments are stored on the disk 3. Pages and segments are transferred to memory when needed Diff...
Good Preservation of games Many games cannot be preserved without piracy they enter the open domain after approx. 25 years Piracy can be morally justifiable Power to the consumer M...
Client Side Processing Pre processing prior to server communication Interactivity Java Script Run in browser Enables users to have a better web experience Better website functional...
Protocols are a set of standardised rules that computers must follow in order to communicate with each other and be compatible with each other.
A sort based around sorting values into values smaller and larger than a pivot point. It is recursive, repeating until handling a list/segment of one. Explanation info To explain....
An unordered collection of labelled items. Traits | Homogenous? | No | | | | | Static/dynamic? | Static | | Mutable? | No | Example Usage info Python does not natively implement re...
Stores a continuous sequence of the same bits as a pair containing: the bit value the repetition of the bit value Implementation Example Example Application: Text
Drawing
info Unfinished. Client side processing is the processing of anything being done on the client. Server side processing is the processing of anything being done on the server. Advan...
The TCP/IP model also known as the ATIL model is composed of four different layers: Application Transport Internet Link It directly correlates to the OSI model. out of specificatio...
Client Server Model A network topology in which the: client accesses requests data from the server client initiates communication to the server server waits for requests from the c...
Transaction processing is any form of information processing, divided into individual and indivisible operations labelled transactions. Each transaction must either succeed or fail...
Translators are programs which convert program source code from a high level langauge to a low level language . There are three types: Assemblers Compilers Interpreters Assemblers...
An ordered collection of items. Traits | Homogenous? | No | | | | | Static/dynamic? | Static | | Mutable? | No | Example Usage
LAN Local Area Network PAN Person Area Network WLAN Wireless Local Area Network CAN Campus Area Network MAN Metropolitan Area Network WAN Wide Area Network SAN Storage Area Network...
File Repair Attempts to correct issues within a file, restoring them to its original working state. Backups Creates a store of the current operating system. This may be either a fu...
| Sign | Summary | Description | Notes | | | | | | | | All | Represents all. | | | % | Any | Represents zero or more characters. | Analogous with asterisk. | | | One | Represents a...