Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A level Comp. OCR > Paper 1 (my version) > Flashcards

Paper 1 (my version) Flashcards

1
Q

ALU definition

A

part of the CPU that completes all the arithmetical and logical calculations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Control Unit definition

A

component of the processor which directs the operations of the CPU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

CU jobs (5)

A
  • accepting next instruction
  • decoding instructions
  • storing resulting data into memory
  • managing flow of data between CPU and other components
  • controlling and coordinating CPU activities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

PC definition

A

holds address of next instruction to be executed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ACC definition

A

stores results from calculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

MAR definition

A

holds address of location that is to be read from or written to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

MDR definition

A

temporarily stores data that has been read or data that needs to be written

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

CIR definition

A

holds the current instruction being executed, divided up into operand and opcode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Data bus

A

bi-directional bus used for transporting data and instructions between components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Address bus

A

used to transmit the memory addresses specifying where data is to be sent to or retrieved from

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Control bus

A

bi-directional bus carrying command and control signals to and from every other component in a computer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Fetch Decode Execute

A

The complete process of retrieving an instruction from store, decoding it and carrying it out. Also known as the instruction cycle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Factors affecting performance of CPU (3)

A
  • clock speed
  • cache
  • number of cores
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the purpose of pipelining?

A

To reduce the amount of CPU which is kept idle, thereby improving efficiency and performance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Von Neumann Architecture definition (3)

A
  • a computer architecture with a single control unit, ALU and special registers within the CPU
  • instructions and data are stored in the same place in memory, in the same format
  • instructions and data use the same set of buses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Approaches to overcome Von Neumann bottlenecking (3)

A

Caching, prefetching, multithreading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Von Neumann bottleneck

A

idleness of the processor due to the shared buses being unable to fetch instructions and data from memory fast enough

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Von Neumann Architecture disadvantages (3)

A

program can be corrupt, overwritten, bottleneck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Harvard Architecture Advantage

A

quicker execution as memory and data can be fetched in parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

RISC advantages (4)

A
  • enables pipelining as each instruction is the same length and takes a single cycle to complete
  • program runs faster
  • simple hardware as fewer circuits are needed for the lower number of operations,
  • lighter and produces less heat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

RISC definition (2)

A
  • Reduced instruction set computer
  • instruction set is comprised of a small number of simple, fixed length instructions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

CISC definition (2)

A
  • Complex instruction set computer
  • instruction set comprised of a large number of complex variable length instructions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

CISC advantages (2)

A
  • programming simple as single instruction can do complex operation
  • code small so little RAM needed to store instructions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

CISC info (6)

A
  • emphasis on hardware
  • multiple instruction sizes and formats
  • less registers
  • more addressing modes
  • extensive use of microprogramming
  • pipelining difficult
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

RISC info (6)

A
  • emphasis on software
  • instructions of same set with few formats
  • uses more registers
  • fewer addressing modes
  • instructions take one cycle time
  • pipelining is easy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

GPU definition

A

coprocessor that has a large number of cores allowing it to process multiple streams of data at the same time, and has its own RAM, effective for simpler operations on larger data sets, designed to perform a single repetitive task

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

CSS definition

A

Cascading style sheets and defines the appearance of a webpage using selectors such as classes. Can be place within HTML or externally in a file.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Server definition

A

a device that provides a central point of access

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

client definition

A

a device that requests data stored on a server

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Pipelining definition (4)

A
  • concurrent processing of multiple instructions
  • one instruction is fetched while the previous one is being decoded and the one before is being executed
  • increases speed of execution
  • in case of a branch, the pipeline is flushed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

HTML definition

A

hypertext markup language, and defines the structure and content of a webpage using tags

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Indexing (4)

A
  • a spider visits a site, either by selecting it from an existing list or following a link
  • it then records information, such as text and metatags and records the position of each word within the page
  • storing them in an index
  • it the follows links to other sites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Damping factor

A

a value from 0 to 1 that is the probability that a user will not follow a link

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

object

A

instantiated from a class

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

method

A

an action an object performs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

attribute

A

a value held by the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

3 factors affecting output value by the PageRank algorithm

A
  • damping factor
  • number of links to target site
  • PageRank score of other sites linking to it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

PageRank algorithm (2)

A
  • checks the number and quality of links to a page to determine roughly how important the page is
  • the assumption is that websites of greater importance are more likely to be linked to from other websites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

client-side processing advantages (2)

A
  • reduces load on server
  • websites will work quicker for user
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

server-side processing advantages (1)

A
  • processing done away from user’s control
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

packet switching (5)

A
  • data split into equally sized chunks called packets
  • each packet has a header of information that includes destination device IP address and TTL
  • each packet is then placed on the network and may travel by a different route
  • at each node, the destination address is read and the best rope is found
  • packets need to be reordered at the destination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Why are protocols important for networking?

A

allows devices to communicate by ensuring all devices follow the same rules so they interpret data the same way

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Benefits of OOP (4)

A
  • modularity: easier to test and debug as objects are self-contained with their data and behaviours. This allows a team to work on multiple objects simultaneously
  • reusability of code: inheritance and polymorphism can be used to create subclasses that allow, with a small amount of extra code, to have many objects with various functionalities and characteristics. the high level of abstraction means classes can be used as a black box which saves development time
  • flexibility: polymorphism allows the same method to acquire different behaviours from the parent class
  • encapsulation of data: maintains the object’s data’s security , as encapsulation forces developers and user to use methods (with built in validation) to change data stored in attributes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Object-oriented programming

A

Makes use of classes (templates that have methods and attributes) from which objects that represent real-world items are made

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

encapsulation

A

a method of maintaining data integrity by only allowing class methods access data in an object’s attributes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

disadvantages of OOP (5)

A
  • different style of programming and requires alternative style of thinking
  • difficult for programmers accustomed to other paradigms to pick up
  • not suited to all types of problems
  • where few components are reused, OOP may lead to longer more inefficient program
  • unsuitable for smaller problems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

encapsulation advantages (3)

A
  • protects data
  • reduces the chance of inconsistencies
  • ensures objects can only be changed in the intended way
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

inheritance (2)

A
  • when a class takes on the attributes and methods of a parent class
  • may override and have additional attributes of its own
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

LAN

A

group of devices connected over a small geographical area, where infrastructure is usually owned by the network owner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

advantages of inheritance (2)

A
  • promotes reusability: when a class inherits another class, it can access all the functionality of the parent class
  • reliability: the parent class’s code will already be tested and debugged
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

disadvantages of inheritance (2)

A
  • inherited methods work slower than normal functions as there is indirection
  • data members in the parent class are often left unused which may lad to memory wastage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

polymorphism (3)

A
  • when methods behave differently according to the context in which they are used
  • overriding is used to redefine a method within a subclass and alter the code so that it functions differently and produces a different output
  • overloading is passing in different parameters into a method
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

advantages of polymorphism (2)

A
  • subclass can have their own behaviours from parent class
  • supports a single variable name for multiple variable types
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

immediate addressing (3)

A
  • operand holds the actual data to be used
  • allows quick and simple data access (as no fetch required)
  • limited by the size of the operand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

direct addressing (3)

A
  • operand holds the address of the data to be used
  • data can potentially be larger than that of immediate addressing
  • address range limited by size of operand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

indirect addressing (3)

A
  • operand holds the address of where the data to be used is stored
  • allows larger range of addresses to be fetched
  • multiple fetches required to access data
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

indexed addressing (2)

A
  • operand holds an address which is offset using Index Register to find true address of data to be used
  • allows Index register to be manipulated to access data stored sequentially
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

switch (2)

A
  • joins devices on a LAN
  • receives packets and sends them to the devices with a MAC address corresponding to the MAC address in the packets header
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

bridge

A

a device that connects two similar networks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

router (3)

A
  • a device that routes packets between networks based on network-layer addresses
  • determines the best path across a network
  • used to connect separate LANs to form a WAN
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

TCP/IP stack layers (in order of application) (4)

A
  • Application: specifies what protocol needs to be used to relate the application that’s being sent (e.g. HTTP, POP3)
  • Transport: establishes an end-to-end connection between the source and recipient devices, breaks the application data down into segments (TCP) or datagrams (UDP). Sequence numbers are allocated, and source and destination port numbers are added to the header. For TCP, delivery is acknowledged, and lost segments are retransmitted
  • Internet: prepares packets for the internet. Source and destination IP addresses are added at this stage
    Link: this is the connection between network devices
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Von Neumann Architecture (3)

A
  • computer architecture with a single control unit, ALU and special registers within the CPU
  • instructions and data are store in the same place in memory and in the same format
  • instructions and data use the same set of buses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Functions of an OS (5)

A
  • provides a user interface
  • manage peripherals
  • handling interrupts
  • provide security
  • provide utilities for system maintenance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Harvard Architecture

A

a computer architecture with separate memory and buses for instructions and data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

prefetching

A

fetching instructions or data from their original storage in slower memory to a faster local memory before it is actually needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

caching (2)

A
  • temporary storage of program instructions or data that has already been used once and may be needed again
  • they can be fetched again more quickly increasing processing speed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

virtual storage

A

storing information remotely and accessing it through a computer with access to the same system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

virtual storage limitations (2)

A
  • network connection speed
  • high costs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

RAM

A

random access memory, a form of primary storage used to hold programs in use and is volatile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

fastest cache

A

L1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

largest cache

A

L3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

co-processor

A

an additional processor used for a specific task

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

GPU (3)

A
  • graphical processing unit
  • a coprocessor that has a large number of cores, allowing it to process multiple streams of data at the same time, and has its own RAM
  • effective for simpler operations on larger data sets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

gateway

A

Provides a connection between two dissimilar networks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Firewall

A

A piece of software that monitors/filters packets going to and from a network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

paging (2)

A
  • memory split into fixed size physical divisions called pages
  • causes internal fragmentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

segmentation (2)

A
  • memory split into unevenly sized divisions call segments
  • causes external fragmentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Why scheduling is important (3)

A
  • to process as many jobs as possible, quickly and fairly
  • maximise number of interactive users with fast response time
  • efficient use of recourses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Why memory management important (4)

A
  • organises use of main memory by converting logical addresses to physical addresses
  • allows programs to share or allocate memory
  • protects processes and data from each other
  • enables programs larger than main memory to run
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Preemptive scheduling algorithm

A

Jobs are actively made to start and stop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Non preemptive scheduling algorithm

A

Once a job is started, it is left alone until (it is) finished

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

First Come, First Served

A

A non preemptive scheduling algorithm where jobs are dealt with in the order they arrive (queue)

83
Q

Round Robin

A

A preemptive scheduling algorithm where a time slice is given to each job and they are dealt with on a FIFO basis. If the job does not finish within a time slice it joins the end of the queue

84
Q

Shortest Job First

A

A non preemptive scheduling algorithm where the queue is sorted/ordered by expected execution time, with shorter jobs at the front

85
Q

Shortest Remaining Time

A

A preemptive scheduling algorithm where the queue is sorted by expected remaining execution time with shorter jobs at the front. If a new job requires less time than the currently running job the currently running job is stacked so the new job can run

86
Q

multi-level feedback queue (4)

A
  • a preemeptive scheduling algorithm that uses queues of tasks, where each queue has different levels of priority
  • jobs are initially added to a queue with a certain level of priority
  • if a process uses too much CPU time, it is moved to a lower priority queue and if a process has been idle for a long time, it is moved to a higher queue to avoid starvation
  • processes that depend on input/output devices require a lot of processing time, so are kept in high priority queues, and processes that are quick to complete are served first
87
Q

interrupt

A

a signal generated by software or hardware to indicate to the processor that a process needs attention

88
Q

interrupt service routine (4)

A
  • current FDE cycle completed
  • if interrupt if higher priority than current task, contents of registers pushed to a stack
  • the relevant ISR is loaded by loading the address of its first instruction into the PC
  • when the ISR is complete the previous contents of the registers are popped and loaded back into the registers
89
Q

multi-user system (2)

A
  • multiple users can access the same system
  • uses a scheduling algorithm to ensure processor time is shared fairly and avoid the risk of processor starvation so users can access the same system at the same time without affecting the other user
90
Q

multi-tasking system (2)

A
  • enable the user to run more than one program at the same time
  • this is done by time slicing to quickly switch between programs and applications in memory
91
Q

multi-core processor

A

more than one processing unit in a single processor which can independently process instructions at the same time

92
Q

distributed system (2)

A
  • a system which is run across multiple devices
  • allowing the load to be spread across multiple computer processors using parallel processing
93
Q

embedded system (3)

A
  • software used to manage the device
  • built into the device itself and specific to the hardware
  • stored in ROM so it cannot be changed
94
Q

real-time system (3)

A
  • a system that gives a response within a fixed time frame
  • redundancy is built in so the system can handle sudden increases in input
  • rarely run at capacity
95
Q

BIOS

A

responsible for loading the OS when the computer fist turns on

96
Q

devices drivers

A

utility software used by the OS to communicate with peripherals, specific to the computer’s architecture and OS

97
Q

Utility software

A

software that performs a specific task, usually related to the upkeep of the system

98
Q

Register (2)

A
  • temporary storage within the CPU used for a single specific purpose
  • faster access than RAM
99
Q

Operating system

A

A collection of software that works together to provide an interface between the user and computer

100
Q

What is BIOS (4)

A
  • power-on-self-test: ensures all hardware is correctly connected and functional
  • checks the CPU clock, memory and processor are operational
  • tests for external memory devices connect to the computer
  • bootloader passes control to the kernel which initialises the OS
101
Q

Virtual machine

A

a computer system created using software on one computer in order to emulate the functionality of another separate computer

102
Q

First Normal Form (1NF)

A

A relation that has a primary key and in which there are no repeating groups.

103
Q

Second Normal Form (2NF)

A

a relation that is in first normal form and has no partial dependencies (no attribute can depend on part of a composite key)

104
Q

Third Normal Form (3NF)

A

a relation that is in second normal form and has no transitive dependencies

105
Q

Transaction

A

A single operation executed on data

106
Q

Redundancy

A

the unnecessary duplication of data, resulting in larger files, slower performance and inconsistencies

107
Q

Rules for transactions (4)

A
  • atomicity: a transaction must be processed in its entirety or not at all
  • consistency: a transaction must maintain the referential integrity rules between linked tables
  • isolation: simultaneous executions of transactions should lead to the same result as if they were executed consecutively
  • durability: once a transaction has been executed it will remain so regardless of the circumstances surrounding it, such as the event of a power cut
108
Q

The 4 database operations

A
  • create: create table and insert into
  • read: from select
  • update: alter table and update
  • delete: drop table and delete from
109
Q

Foreign key

A

primary key used to make a relationship from one table to another

110
Q

Secondary key

A

non-identifying attribute that can be used as an index for quick searching

111
Q

Flat file

A

a database where all data is stored in a single table

112
Q

Flat file advantages

A

Quick and easy to set up

113
Q

referential integrity

A

the value for a foreign key must be either null or match one of the data values in the primary key of the corresponding table

114
Q

Flat file disadvantages

A

Data redundancy

115
Q

IP address

A

a logical identifier that uniquely identifies a device on the network

116
Q

Hash (2)

A
  • a fixed-size value generated by applying an algorithm to an input
  • hash functions are one-way
117
Q

How a hash table can be used to handle collisions (2)

A
  • linear probing: move through the structure one space at a time to find the next free space
  • chaining: each location points to a new linked-list, the new item is added to the end of the linked list
118
Q

Big O complexity for Linked List (3)

A
  • linked list searched by starting at the first node and following the pointers until the desired value is found or the end of the list is reached
  • a list of size n on average takes a time of n/2 to search
  • this makes the big O complexity O(n)
119
Q

Big O complexity for Hash table (4)

A
  • searching hash table requires the key to be hashed and the correct location accessed
  • the time this takes is dependent on the time to create the hash
  • if we ignore collisions, O(1) / constant complexity
  • as list grows collisions more likely, so time taken grows linearly
120
Q

Hash benefits (2)

A
  • security: hash security in database to make sure they cannot be read if they are stolen as hashing is a one-way process
  • Access: values can be quickly access by using the hash values
121
Q

Features of a good hashing algorithm (3)

A
  • Low chance of collision
  • quick to calculate
  • provides a smaller output than input
122
Q

Linked list (2)

A
  • a dynamic data structure where each node consists of data and a pointer
  • the pointer gives the location of the next node
123
Q

Application software

A

software designed to be used by the end user to perform a specific task

124
Q

Applications software examples (3)

A

word processors, spreadsheets, web browsers

125
Q

System software

A

low-level general software that is responsible for running the computer system smoothly

126
Q

System software examples (4)

A

library programs, utility programs, operating system, device drivers

127
Q

Compiling stages (3)

A
  • lexical analysis: comments and white spaces removes, variables and subroutines are stored in symbol table, code is converted into a series of tokens, which is passed to the syntax stage alongside the symbol table
  • syntax analysis: the code is checked to ensure it follows the rules of the language, this is often accomplished by placing the tokens into a tree, where it breaks, errors are generated, if not rules are broken it moves onto the next stage
  • code generation: the object code is searched through to find the areas that can be made more efficient, insignificant, redundant parts of code are detected and removed, repeated sections of code may be grouped and replaced with a more efficient piece of code
128
Q

Object code

A

the output of a compiler or an assembler

129
Q

Library

A

A prewritten program

130
Q

Linkers

A

links external modules and libraries included within the code

131
Q

Static linkers (3)

A
  • modules and libraries are added directly into the main file
  • this increases the size of the file
  • any updates to modules and libraries externally will not affect the program
132
Q

Dynamic linkers (3)

A
  • addresses of modules and libraries are included in the file where they are referenced
  • when the program is run, the loader retrieves the program at the specified address so it can be executed
  • files remain small and external updates feed through to the main file; there is no need to rewrite code
133
Q

Loader

A

when file executed, loader retrieves the library or subroutine from the given memory location

134
Q

Optical devices (2)

A
  • are read from and written to using lasers
  • binary information is represented by parts of the disc which either reflects or scatter the incident laser light written in spiral tracks on the disc’s surface
135
Q

Flash memory (2)

A
  • uses silicon semiconductors to form logic gates NAND and NOR to store electrical charges in the states high and low (representing 1 or 0)
  • non-volatile
136
Q

Magnetic memory

A
  • data stored by altering the magnetic field of a small section of the tape or disk
  • one orientation represents binary 1, the other represents 0
  • written using a read head
  • the read head can then read the magnetic field to retrieve the data
137
Q

Immediate code (2)

A
  • code that is halfway between source code and machine code
  • independent of processor architecture so can be used across different machines and operating systems
138
Q

Uses of virtual machines (2)

A
  • protection from malware: malware will affect the virtual machine not the device being used
  • running incompatible software: programs specific to different operating systems can be run within a virtual machine, saving money required to purchase that OS
139
Q

Virtual machine drawbacks

A

Running intermediate code in a virtual machine can be considerably slower compared to running low-level code on the device it was designed for

140
Q

Open source software

A

open source code can be used by anyone without a license and is distributed with the source code

141
Q

Closed source software

A

software that has been developed by a company and has restrictions on its use, copying and modification

142
Q

Compiler (4)

A
  • translates high-level code into object code all at once
  • once compiled can only be executed on certain devices
  • specific to a processor type and OS
  • code can run without translator present
143
Q

Interpreter (4)

A
  • translates and executes a program line-by-line
  • interpreter is required for code to run on different devices
  • code can be run on a range of devices
  • code more portable
144
Q

GPU uses (2)

A
  • image processing
  • machine learning
145
Q

ROM (4)

A
  • read only memory
  • memory which its contents can be read but not written to
  • software fixed during manufacturing
  • non-volatile
146
Q

Assembler

A

translates a program in assembly language into machine code.

147
Q

Waterfall model (2)

A
  • each identified stage of development flows from the previous one and down to the next
  • feedback from each to the previous takes place independently of the forward flow
148
Q

Waterfall advantages (4)

A
  • linear: easier to manage, low cost, schedule/ end dates, allocate roles, check progress
  • user involved early and late stages
  • more resilient to staffing changes (heavily doc.)
  • ideal when requirements clear
149
Q

Waterfall disadvantages (4)

A
  • too rigid for some projects
  • heavily documented
  • deliverable late in project
  • not much customer involvement
150
Q

Extreme programming (3)

A
  • intended to improve software quality and responsiveness to changing customer requirements
  • advocates frequency releases in short development cycles
  • improves productivity and introduces checkpoints where requirements can be adjusted
151
Q

XP disadvantages (2)

A
  • suffer from creep scope
  • can be affected by staffing changes
152
Q

XP advantages (2)

A
  • paired programming
  • high quality code
153
Q

Spiral model (2)

A
  • four quadrants: planning, risk analysis, design methods, client and management evaluation
  • moves around each cycle one at a time in a spiral
154
Q

Spiral disadvantages (1)

A
  • expensive
155
Q

RAD model (2)

A
  • includes online development and repeated prototyping and evaluation
  • suited to interactive systems
156
Q

RAD advantages (1)

A
  • quicker development
157
Q

Agile methodologies (2)

A
  • describes the responsive development of a system made of small software modules
  • group of collaborators who work concurrently and closely under a leader
158
Q

Lossy Compression

A

A compression scheme where their generally involves a loss of resolution in parts of the image where experiences shows that it will be least noticed.

159
Q

Lossless Compression

A

A compression scheme that allows the original images to be recreated.

160
Q

Symmetric Encryption

A

a secret key is applied to the text to change the content in a particular way

161
Q

Asymmetric Encryption

A

involves a pair of keys to encrypt and decrypt a message so that it arrives securely

162
Q

Primary Key

A

A field that uniquely identifies a record in a table

163
Q

Normalisation

A

The process of arranging data in tables and setting their relationships to move them through normal forms

164
Q

Ways to capture data (4)

A
  • cheques
  • MICR
  • OMR
  • OCR
165
Q

Record Locking

A

A technique of preventing simultaneous access to data in a database, to prevent inconsistent results. The classic example is demonstrated by two bank clerks attempting to update the same bank account for two different transactions.

166
Q

DNS

A

The Internet’s equivalent of a phone book. They maintain a directory of domain names and translate them to Internet Protocol (IP) addresses

167
Q

Protocol Layering

A

simplify networking designs by dividing them into functional layers, and assigning protocols to perform each layer’s task.

168
Q

WAN

A

a collection of computers on the same network spread out over a geographically large area

169
Q

Circuit Switching

A

A method of sending data over a WAN in which two network nodes establish a dedicated communications channel through the network before the nodes may communicate. All data then follows this same path for the duration of the data transfer.

170
Q

Proxies

A

applications that accesses data on a different computer system or network. It controls the access of authorised users to data and allows the operation of the system to be isolated from control by external users.

171
Q

Client-Server

A

A method of network organisation in which network stations make use of resources available at one or more servers.

172
Q

Peer to Peer (2)

A
  • a network where all of the devices have the same level of authority
  • devices share data
173
Q

Directed Graph

A

the order of the vertices in the pairs in the edge set matters

174
Q

Undirected Graph

A

the order of the vertices in the pairs in the edge set doesn’t matter.

175
Q

Stack

A

a dynamic data structure of the form Last In First Out (LIFO)

176
Q

Queue

A

a dynamic data structure of the form First In First Out (FIFO)

177
Q

Tree

A

abstract data type that simulates a hierarchical tree structure, with a root value and sub-trees of children with a parent node, represented as a set of linked nodes

178
Q

Binary Search Tree (3)

A
  • similar to tree
  • each node can have only up to 2 nodes
  • all left nodes have smaller value than root node
179
Q

Hash Table (2)

A
  • calculated value used to mark the position in the table where the data item should be stored
  • accessed directly
180
Q

the purpose of a D-type flip-flop

A

to store the value of a bit

181
Q

Flip Flops (3)

A
  • exist in two states: 0 or 1
  • faster RAM updates more quickly
  • updated every clock cycle
182
Q

inputs and outputs used by D-Type flip flop (5)

A
  • inputs: D and clock
  • outputs: Q and not Q
  • Q and not Q only change when clock is 1
  • D is the value to be stored
  • Q is the value being stored, not Q is the inverse
183
Q

Half Adders

A

adds two input variables

184
Q

Full Adders (2)

A
  • adds two input variables
  • carries a bit from another addition as well as two inputs
185
Q

HTML id attribute vs HTML class attribute (2)

A
  • only one element can have an id
  • class can be used assigned to multiple elements
186
Q

purpose of constructor

A

set initial value of attributes

187
Q

2 advantages of client-server over peer-to-peer (2)

A
  • central updates
  • data is stored in one place, so secure
188
Q

client-server disadvantages

A

expensive to set up and maintain

189
Q

peer-to-peer disadvantages

A

less secure, everyone has same level of authority

190
Q

DNS role in loading website (4)

A
  • DNS locates IP address of domain
  • DNS checks if resolver has IP, if dos sent straight back to user
  • if not resolver checks root name server where domain is form
  • resolver checks top level domain where domain is form, which then checks authoritative name server which sends IP address found to DNS, DNS saves IP and domain then sends to user
191
Q

procedural programming

A

breaks a solution down into subroutines, these subroutines are rebuilt and combined to form a program

192
Q

procedural programming advantages

A

can be divided between a team with different team members tackling different subroutines

193
Q

Copyright, Designs and Patents Act (4)

A
  • regulated intellectual property
  • brought to protect people’s property online
  • doesn’t expire until 25-70 yrs after death of creator
  • if individual believes work has been copied, their responsibility
194
Q

Regulation of Investigatory Powers Act (4)

A
  • investigation, surveillance and interception of communication by public bodies
  • enforces internet providers and mobile phone companies to give up information upon request from authorised authority
  • ensures their networks have sufficient hardware installed to facilitate surveillance
  • powers extend to small agencies
195
Q

Data Protection Act (7)

A
  • data shouldn’t be kept longer than necessary
  • data should be accurate and up to date
  • data shouldn’t be transferred out of the EU
  • data should be protected by adequate security measures
  • data collected should not be excessive
  • data only used for specific purpose
  • customer has right to see and ask for data
196
Q

Computer Misuse Act (5)

A
  • aimed at criminalising unauthorised access to a computer system
  • unauthorised access to computer materials
  • unauthorised access with intent to commit further offences
  • unauthorised modification of computer materials
  • creating and distributing material such as viruses
197
Q

computer in the workforce (4)

A
  • increase efficiency and productivity
  • higher productivity lowers labour costs
  • removes need to work in repetitive environment
  • contributes to rise in structural unemployment
198
Q

Automated decision making (4)

A
  • what users displayed on social media (closed-mindset society)
  • relying on algorithms could result in people being mistreated
  • ethical questions (e.g. driverless cars)
  • algorithms should be tested more so no bias
199
Q

artificial intelligence (4)

A
  • raises questions about accountability
  • used in voice recognition
  • used to detect patterns and fraud
  • used in expert systems to replicate knowledge of an expert
200
Q

environmental effects (4)

A
  • people throw away more devices as more affordable
  • computer components toxic and contaminate water
  • to power devices uses fossil fuels
  • growth in environmentally friendly tech
201
Q

censorship and the internet (4)

A
  • ISPs block content associated with terrorism
  • people worry that censorship is misused to push certain ideology
  • some believe in ‘free internet’, nothing filtered
  • may be used to maintain productivity and prevent distractions
202
Q

monitor behaviour (4)

A
  • employers tracking websites workers accessing
  • surveillance systems
  • some argue unethical and against basic human rights
  • others argue essential to put people off committing crimes
203
Q

analyse personal information (3)

A
  • data reveals insights about people
  • pressure on large firms to be more transparent with data collected
  • ethical concerns about whether companies have responsibility to feedback trends uncovered
204
Q

layout, colour paradigms and character set (4)

A
  • equality act, illegal to discriminate certain groups
  • must be easy to navigate between pages
  • people with visual impairments should be able to alter text
  • websites should be as accessible as possible

A level Comp. OCR (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions