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1

Bitwise XORing...

toggles a subset of the bits in the value

when you use a 1 the bianry is toggled/ switched around and 0s there is no impact

2

Depth First algorithm

1. PUSH the first node onto the stack
2. Repeat:
a. push each node onto the stack until a child node is reached
b. visit the node which is the lowest you can reach
c. if no node to visit pop off the stack
3. Until stack is empty

3

Encryption

Encryption is the process of encoding a message so that it can be read only by the sender and the intended recipient.

4

serialisation

Serialisation ensures that transactions do not overlap in time and therefore cannot interfere with each other or lead to updates being lost

5

Class

a template to set out a define what attributes an object of a certain type should have

6

how is redundancy used usefully

organisations build in redundancy e.g. duplicate hardware so that if the main system fails the backup can take over

7

X∧X=

X

8

do until loop pseudocode

do
code
until
condition

9

Sequence

do one statement after another in the correct order

10

Symmetric Encryption

Symmetric Encryption is when the same key is used to encrypt and decrypt the message. Both party’s must know the key and also keep it secret.

11

NOT

reverses the outcome of the expression

12

Byte Scale

bit, nibble, byte, kilobyte, mega, giga, tera, peta, exa, zetta, yotta

Multiple by 1024 to move up

13

Method of capturing data (Manual)

Paper data capture form (read by OCR & OMR or typed in manually)

14

purpose of operating systems: managing external devices

Using device drivers to translate operating system instructions into those understood by specific models of hardware device

15

How are character sets used to represent text?

When character in the set has a corresponding binary value which is a set number of bits. These are stored in a sequence that represents a word etc.

16

Capacity of magnetic

640 GB - 1TB

17

clock use

synchronise the change of state of flip flop circuits

18

linked lists

A list of data together with a set of links to sort the data. Data is stored in the order its input and pointers are used to link the data into the desired order.

19

Selection

do a set of statements based on conditions allow your code to make choices- otherwise known as branching

20

Peer-to-Peer Networking

No central computer, all computers are connected to each other locally or over a WAN

21

disadvantages of Client-Server

-Can be expensive to set up and to manage
-Server is single point of failure

22

how to convert floating point binary to denary

1) First work out the denary number in the exponent which tells us that the binary point moves 'n' places to the right
2) Write out a new binary weighting line with the point in the right place and then convert into denary

23

components of a packet

senders address, recievers address, packet contents, sequence number

24

Consistency

Any change in the database must retain the overall state of the database.

25

clock

sequential circuit that changes state at regular time intervals

26

Program Counter

stores the address of the next instruction

27

POST acronym

Power of self test

28

X∧0=

0

29

relationships

one-to-one
one-to-many
many-to-many

30

in two's complement the sign is stored in

the most significant bit

31

direct addressing

where the operand contains the address of the value to be used.

32

preorder dot

left

33

Asymmetric Encryption

Asymmetric Encryption (Public Key Cryptography) is when a public key and a private key is used. The public key is used to encrypt the data and the private key is used to decrypt the data. If you use person X’s public key to encrypt the data only person X’s private key will be able to decrypt it

34

Advantages of networks

- allows sharing of data
- allows collaberative working
- good for communication
- allows sharing of resources e.g. printers, storage and scanners
- easy to backup to a central point

35

Real-time Operating system

Designed to carry out actions within a guaranteed amount of time even when left running for long period.

36

software

program code. Sequences of instructions which are executed in order to perform a task.

37

Client side processing

data is processed on client side and send back to the server. This is used for security as it avoids data transfers.

38

Disadvantages of the agile model

- Not suitable for quick projects

39

Current instruction register

stores the actual instruction that is being decoded

40

if/else Pseudocode

if condition then
code
elseif condition then
code
else
code
endif

41

dynamic

size of the structure can change at runtime

42

Optical storage advantages

Cheap
light weight and portable
Resilient

43

Trace Tables

As you follow code you note down when each variable changes and what each value is

44

structured

the data is organised in a logical way

45

purpose of operating systems: managing the memory

allocating and managing the memory used and relinquished by processes using pages and segmentation. Managing virtual memory

46

constructor of a superclass

public procedure new(inputs)
super.new(inputs)
attribute = input
endprocedure

47

instruction set

a group of instructions that a computer can carry out. unique for computers.

48

code optimisation

(stages of compilation stage 4)
the code is optimised to run as fast as possible by removing redundant code (removing variables and procedures that have been written but never called)

49

Multiple cores

Multiple CPUs working on a single computer

50

Pre-emptive

Once a process has entered the running state it can be stopped

51

Inheritance OO pseudocode

class Dog inherits Pet
code
endclass

52

Address Bus

A one directional bus that transmits memory addresses that are used as operands in programming instructions, so that data can be retrieved from main memory

53

XML (eXstensible Markup Language)

A markup language that uses tags to denote data

54

Methods of sending data

Electronic Data Interchange (EDI) - is the computer-to-computer exchange of business documents in a standard electronic format between business partners.
Application Programming Interface (API) - a prewritten set of subroutines that provide access to the
companies data
- A URL to a file

55

CISC

Complex instruction set computing, large number of instruction each taking multiple machine cycles to carry out.

56

Clock signal

used to synchronise operations

57

font size CSS property

font-size

58

Uses of real-time operating systems

Airline control, theatre bookings, heart monitors, production lines, radar systems

59

purpose of operating systems: providing networking

communication through protocols and other machines and devices

60

Durability

Once a change has been made to a database it must not be lost due to a system failure.

61

wildcard

*, selects all the elements

62

Tuples

are lists that cannot be edited, they are immutable

63

Hash tables

an array which is coupled together with a hash function.

64

stack data structure

A stack is known as a LIFO, a single pointer is used to point to the top item of the stack, when a new item is pushed onto the stack the pointer is incremented. When an item is popped off the stack the pointer decrements to point to the new top of the stack.

65

second normal form

1. Check the data is already in 1NF
2. Remove any partial dependencies
3. ‘fix’ any many to many relationships you discover

66

Open Systems Interconnection 7 layer model

(7) Application Layer
(6) Presentation Layer
(5) Session Layer
(4) Transport Layer
(3) Networking Layer
(2) Data Link Layer
(1) Physical Layer

67

Query SQL

SELECT *
FROM tblName
WHERE conditions

68

stepwise approach

breaking down a problem into smaller sections

69

Server side processing

used to interact with permanent storage like databases or files. It also renders the pages to the client

70

sequential files

where the order of data is maintained

71

how to do CSS in HTML

72

Data Protection Act parts

Data processed fairly and lawfully
Data should only be collected for specific purposes
Data should be relevant and not excessive
Data should be accurate and up to date
Data should not be kept longer than needed
The user has a right to access and correct data
The organisation must have suitable security
Data can not be transferred outside the UK to any country with no data protection laws

73

How is a stack used in a ISR

when an interrupt comes the current instruction is pushed onto the stack. Once the interrupt has finished it pops the instruction off the stack and processes it

74

OR (+)

75

protecting agaisnt hacking:

-Packet snifferes
-User access logs

76

Attribute

variables contained within and associated to an object

77

BIOS

checks that the hardware is connected is connected and working in what is known as a power on self test

78

polling

The CPU checks with each device if it needs attention. Inefficient and wastes time as some devices will not want attention when called upon

79

how does arithmetic (signed) right shift work?

shift everything to the right and backfill the space with 1s

80

normalising a positive binary number

back fill with 0s

81

Input device examples

Key board
Card readers
Microphones
Cameras
Barcode scanners
OMR/OCR
Mice
Sensors
Magnetic stripe reader
touch pads

82

Object Orientated language

coders develop a solution which consists of objects that have been modelled on the real worl.

83

sparse graph

A graph which has few edges in relation to vertices

84

Solid-State Storage

uses flash memory so data is read and written directly to blocks and pages on the silicon micro-chips

85

graph

a set of edges/arcs connecting vertices/nodes

86

linking a css/javaScript file

87

Link Layer

(4) Passes data to the physical network

88

Hashing Databases

transforms a string of characters in a record into a shortened form that can be used as a disk address

89

De Morgan's Law

¬ (A∨B) = (¬ A) ∧(¬ B)
NOT (A OR B) is the same as (NOT A) AND (NOT B)

90

Foot Mouse

press key/click button with their foot to send signal.

91

Secondary key

any field in a database which is not a primary, candidate or foreign key. They are used to order queries.

92

Bitwise manipulation

bitwise shifts and masks

93

Bytecode

An intermediate representation which combines compiling and interpreting and is run by a byte code interpreter

94

multi-dimensional arrays

an array containing one or more arrays.

95

Advantages of Using encapsulation

- reduces chance of error
- consistent changes
- prevents accidental changes

96

word

equal units of memory. each with separate memory addresses.

97

fragmented disk

over time a disk becomes fragmented as old files are deleted and new files are added, free space often becomes scattered across a disk and a program has to be split and spread across a disk to fit. The more fragmented the slower the computer performs

98

procedure

a self-contained set of commands that can be called from different parts of the program.

99

Algorithm for insertion into a binary tree:

1. If tree is empty enter data item at root and stop; Current node = root
2. Else repeat:
a. If new data item is less than value at current node go left, else go right.
b. Current node = node reach (null if no node)
c. Until current node is null
3. Create new node and enter data

100

different traversal methods

preorder
inorder
postorder

101

Coacial Copper Cables

older, slower and cheaper

102

node at the top of the tree

root node

103

Chip Multi Processor (CMP)

a single chip which contains 2 or more independent CPUs which can execute independent instructions

104

border width CSS property

border-width

105

factors to consider when choosing applications (9)

speed
does it provide the necessary functionality
cost and pricing
hardware requirements
memory
convenience
is it well used, tried and tested
is it available off the shelf or will it have to be hand written

106

TCP/IP stack

Application Layer
Transport Layer
Internet layer
Link Layer

107

Execute

The appropriate instruction/ opcode is carried out on the data/ operand

108

Artificial intelligence

writing software and algorithms which appear to behave as if they were intelligent

109

What is a more complex data type called?

composite types

110

Star topology disadvantages

Can be expensive to set up because of the length of cable required
Central device is a point of failure

111

Uses of assymetric encryption

used for transfering data e.g. online shopping

112

basic Boolean operators

AND
OR
NOT

113

all attributes are dependent on..

the key, the whole key, and nothing but the key

114

height CSS property

height

115

Peer-to-Peer Model:

all terminals have equal status and there is no powerful central server, each computer acts as both a client and a server.

116

distributed computing

when each computer on a network takes on part of a problem

117

SMTP

Simple Mail Transfer Protocol – used by mail servers and clients to transfer email across the internet

118

Software interrupts

illegal instruction encountered
Arithmetic overflow
new log-on request

119

Uses of CISC

what most desktops use, Intel or AMD

120

Benefits of circuit switching

- highly reliable
- once the circuit is set up communication is fast and generally error free

121

Drawbacks of circuit switching

- dedicated connection therefore even if the channel is free it cannot be used to transmit other data
- inefficient
- requires more bandwidth
- time is taken to determine the physical link before hand

122

Puff/Suck Switch

blow/suck to send signal.

123

Buffer almost empty

buffer allows each device or process to operate without being held up by the other

124

NIC

receive and send electrical signals in a network.

125

partial key dependency

one or more f the attributes depends on only part of the primary key (if the primary key is a composite key)

126

Data Integrity

Data integrity is the maintenance and consistency of data in a data store. The data store must reflect the reality that it represents.

127

internal storage examples

magnetic hard drive, ROM, RAM, internal solid state drive

128

Use of distributed operating systems

Data centres, large companies, weather/financial modelling, data mining trend finding

129

Output device examples

speakers
plotters
printers
monitors
actuators
projectors
LEDs

130

Static

the size of the structure cannot change at run time

131

indexed addressing

The value given is added to the valued stored in the index register to give the memory location.

132

What does a bitwise left shift do?

multiplies the number by 2.

133

Binary -> denary negative exponent

- exponent

134

create an instance of a class OO

objectName = new className(parameters)

135

Breadth first algorithm

1. PUSH the first node into the queue
2. mark as visited
3. REPEAT:
a. visit all unvisited nodes connected to the first node
b. push nodes onto the queue
4. until all nodes visited
5. REPEAT:
a. POP next node from queue
b. REPEAT:
i. visit unvisited nodes connected to current node
ii. PUSH nodes onto quue
c. until all nodes visited
6. until queue empty

136

Absorbtion Law OR

A∧(A∨B)=A
X AND (X OR Y) is the same as X

137

procedural languages examples

Pascal, C, Basic and Python

138

What is ASCII

- A character set
- Maps values to characters
- Uses 7-bits/ 8-bits per character

139

types of interrupts

- hardware
- software
- Input/output

140

A∧ ¬A =

0

141

Contemporary processor architectures

Modern high-performance CPU chips incorporate aspects of both Von Neumann and Harvard architectures

e.g. memory for both data and instructions but cache is divided into instruction and data and multiple parallel data buses

142

Sign magnitude most significant bit

represents + or -
+ = negative
- = positive

143

Hashing

Hashing is the process used to transform a data item into something different. A hashing function provides a mapping between an arbitrary length input and a fixed length output. It is a one-way transformation meaning you cannot get back to the original form.

144

Memory read signal

causes data from the addressed location in RAM to be placed on the data bus

145

Bus request signal

indicates that the CPU has granted access to the data bus

146

polymorphism

when something appears in multiple forms and the program makes sure the correct meaning of a function is run

147

Inserting an item in a hash table:

1. Feed in key to the hash function
2. Go directly to the array index (HashValue)
3. If the location is empty then insert the value
4. Else follow the linked list in sequence until a free space in found and insert the value

148

opcode

the actual instruction

149

0.1

positive

150

Open Source Software

any software which is supplied along with its original source code.
e.g. Linux

151

\

integer division

152

Drawbacks of closed source software

- costs money, can be expensive
- small range of versions of software

153

purpose of operating systems: managing security

servicing and denying requests to access the resources connected to the computer

154

Bottleneck address bus

the width of the address bus determines the maximum possible capacity of the system

155

Input devices for limited mobility

- Foot mouse/pedal
- Camera/eye tracker
- Microphone
- Puff/suck switch

156

Lists

an ordered data structure accessed through an index. the have no predefined scope and can be edited during run time.

157

anchor tag

158

Lossy Compression

Actual data is removed from the file in order to reduce its size. An algorithm is used to strip out the least important data. The original file cannot be restored as data is physically removed.

159

serial file

store data with no specific order meaning if data is added it is simply appended onto the end of the file. You cannot delete data from a serial file. good for storing simple data sets text files and configuration files.

160

commutation LAW OR

A∨B = B∨A
The order in which two variables are OR’ed makes no difference

161

purpose of operating systems: managing the processor

deciding which process to execute next and handling interrupts to the currently executing process

162

Half adder use

adds two bits

163

commutation LAW AND

A∧B = B∧A
The order in which two variables are AND’ed makes no difference

164

end instruction

HLT

165

Binary -> denary positive exponent

+ exponent ->

166

Packet Switching

the data to be transmitted is broke up into individual packets at the source computer. each packet is labelled with an address and sequence number. The packet is then forwarded onto the network and follows its own individual route. Depending on network traffic each packet will take different routes at different times to reach their destination where is is then reassembled.

167

Address bus average width

32 bits

168

normalising a negative binary number

back fill with 1s at the high end and 0s at the low end

169

Possible uses of graphs:

1. Navigation Systems
2. Data Transmission
3. Web page links
4. Social media trends

170

Disadvantages of extreme programming

- Not suitable for programmers separated geographically
- Client must be able to commit to having full time contact with the programmers

171

programming paradigm

a way to classify programming languages based on their features.

172

how to solve hash table collisions

- store the key in in the next available space
OR
- combine with a linked list

173

Data redundancy

The unnecessary duplication of data in a database

174

paragraph text

175

capacity of solid state

around 500 MB

176

Uses of virtual machines

- used on networks to avoid redundant processors
- translating code (Java)

- running different operating systems

177

Mesh Topology

an arrangement where ever node is connected to every other node.

178

Memory Data register (MDR)

stores the data which is to be sent or fetched from memory

179

normalising:
moving the point to the left

+ exponent

180

relationship between high-level and assembly code

one to many

181

uses of a GPU

Will be present on a graphics card in a computer
used in
- Machine learning
- Oil exploration
- Image processing
- Financial transactions

182

virtual storage disadvantages

Expensive if you want to store large amounts of data
Access times can be slow if there is poor internet connection

183

Cop Right Design and Patents Act

protects the intellectual property rights of individuals and organisations. This law makes it illegal to Copy, Modify or Distribute any software or any other intellectual property without permission of the original creator.

184

post order dot

right

185

    ordered list

    186

    Paired Programming

    one programmer types and another checks at the same time.

    187

    border style CSS property

    border-style

    188

    Transmission media

    the wires that connect a network

    189

    system software

    operates, controls and maintain the computer and its components.

    190

    Bitwise ANDing ...

    extracts a subset of the bits in a value

    when the mask is a 1 it retains the value however when the mask is a 0 it outputs just 0s meaning only certain values are extracted.

    191

    main factors effecting CPU performance

    clock speed
    number of cores
    amount and type of cache

    192

    ACID

    Atomicity
    Consistency
    Isolation
    Durability

    193

    What do the nodes on a binary tree contain

    left pointer, data, right pointer

    194

    CDPA year

    1988

    195

    Disadvantages of the spiral model

    - Acknowledge user input
    - Create prototypes to communicate to the user ideas better
    - Better for small projects
    - Simple

    196

    general purpose application software

    A software that can be used for many purposes e.g. word-processor

    197

    FIFO

    first in first out

    198

    digraphs

    has one or more edges that have an arrow indicating you can only go in one direction

    199

    Internet

    many interconnected networks over many different countries via dedicated connections known as backbones

    200

    Embedded Operating Systems

    embedded systems are often run on dedicated hardware so they run with maximum efficiency, with low powered processors and minimal memory

    201

    Switches

    devices used to connect devices on a network, they use the physical hardware MAC address to send data on to the required destination node.

    202

    Output device

    any device which is able to take data which is stored in a digital form and convert it into another format which wee can process e.g. sound, images or vibrations

    203

    drawbacks of assymmetric

    - not as fast

    204

    MOD

    gives the remainder of a division

    205

    three main class sections:

    class name
    attributes
    methods

    206

    Record Locking

    Recording Locking prevents simultaneous access to objects in a database in order to prevent updates being lost or inconsistencies in the data arising.

    207

    Multi-tasking operating system

    one processor is scheduled so that each process receives a very small time slice of processor time giving the impression of them running simultaneously.

    208

    API

    Application Programming Interface governs how two applications should interact

    209

    Adding data from linked lists:

    1. Store the data at the location indicated by the free storage pointer
    2. Alter the free storage pointer to the next free storage space
    3. Work out where in the list the new item should be inserted
    4. Set the pointer for the item that will precede it to the new data item
    5. Update the pointer for the new data item to that previously stored in the item the preceded it

    210

    5 most common primitive data types

    integers, real (float), characters, string and Boolean

    211

    Removing data from linked lists:

    1. If the item to remove is in the first position
    a. Then update starting pointer value of item you want to delete
    b. Update all the pointers
    2. Else if the item is in any other position
    a. Update the pointer value in the preceding node from the one you want to delete to the value of the pointer in the item to be removed
    3. Update the free pointers

    212

    mutable

    structure and data can be changed at runtime

    213

    what connects different networks?

    routers and gateways

    214

    Disadvantages of client side processing

    -Not all browsers support all script
    -Because the scripts are processed by the client, they are dependent on the performance of the clients’ machine

    215

    Utility software

    small programs each with a very specific purpose, which is normally concerned with the maintenance and wellbeing of a computer system

    216

    CSS identifier

    HASHTAG
    #menu{
    background-color: #A2441B;
    }

    217

    for loop pseudocode

    for i=0 to 7
    print(“Hello”)
    next i

    218

    deadlock

    when both users try and access the database at the exact same time meaning neither can edit it

    219

    The text that will appear in the tab heading

    220

    linker (static linking)

    includes links to any library code and place it in a single executable file. this is known as static linking and results in large programs because all the code is held in one file.

    221

    Extreme Programming

    - A type of agile methodology, involving a user imbedded in the company to give feedback.
    - This results in high quality code being developed quicker.

    222

    exponent

    positive of the binary point is fixed on the number line

    223

    What loads the OS into RAM

    the bootloader

    224

    Buffer

    a region of a physical memory storage used to temporarily store data while it is being moved from one place to another

    225

    purpose of operating systems: providing a platform for Software and utility programs

    provides a framework for applications to run, allowing the to, for example, open and close files easily. The user can also interact with operating systems to manage files and use a range of utilities

    226

    token

    a keyword, constant, variable, identifier or operator from the code

    227

    arcs on a tree

    branches

    228

    Relational Database

    A relational database has more than one related table. It is more efficient that a flat file database as no data is duplicated meaning querying is easier.

    229

    uses of functions and procedures

    breaking a problem into manageable sections
    preventing duplicating sections of code when it is needed more than once in a program

    230

    Operating system (System software)

    allows the user to control the computer with ease.
    Provides a virtual machine hiding the true complexity of the computer from the user.
    Manages and controls access to the computer's resources.

    231

    normalising a number

    means that there is only one way to represent the number

    232

    virtual storage advantages

    data can be accessed anywhere so long as you have internet access
    data can be easily shared between devices without having to copy the data and transport it
    the capacity is limitless

    233

    Operating System Roles

    - Provides a user interface
    - manages security
    - provides a platform for utilities/applications
    -manages external devices
    - managing the processor/scheduling
    -managing memory
    - provides a platform for networking
    - managing hardware

    234

    bootloader program

    loads the operating system kernel into memory.

    Stored in ROM

    235

    Where is the waterfall life cycle model used?

    Used in manufacturing industry

    236

    Over-riding

    when the method in the subclass shares the same method as further up in the object tree. the over-ridden method takes precedence and replaces the method further up the object tree

    237

    Characteristics of Procedural

    instructions, sequences, selections, interaction, procedures and functions

    238

    clock

    a device that generates a timing signal which changes at a regular frequency. Its used to synchronise communication between the components of the CPU and the rest of the computer system.

    239

    Cache memory

    Special high speed memory used by a computer. Stores frequently used data and instructions.

    240

    interrupts

    A device sends a signal on the control bus to show the CPU it needs attention

    241

    Unicode

    character set which displays over a million characters

    242

    scheduler

    manages which process to execute next and how much time is allowed to execute a process

    243

    What are character sets needed for?

    needed so that a document which is made on one computer is still readable on another computer. Computers can have more than one character set installed.

    244

    Hardware

    the physical component oft he computer system.

    245

    Microphone

    Make sound to send signal

    246

    advantages of using an external css file

    code only needed to be added to one file but the changes are applied to all the pages that use that css file

    247

    program branch reason

    occurs due to an if statement, function, procedure call or loop.

    248

    primitive data type

    a basic data type provided by the programming language as a basic building block

    249

    array

    allows you to store multiple items of the same data type under a shared common name

    250

    Data mining

    automated process which looks at large sets of data and tries to identify patterns in order to predict something

    251

    different types of operating system

    Distributed
    Embedded
    Multi-tasking
    Multi-User
    Real-time

    252

    Hash function

    code which takes in data called a key and outputs a hash value which is is used to find a fixed index in a hash table

    253

    interpreter

    takes one line of high level source code and converts it directly into machine code then runs it.
    this has a one to many relationship and is useful for debugging code however the security is bad and the code is executed slowly

    254

    CPU vs GPU

    CPUs excel at doing complex instructions on small data sets whereas GPUs excel at simple manipulations to much larger data sets

    255

    Cloud Computing

    Client-Server network via the internet, where files are kept on a remote server and accessed virtually

    256

    What does the DMBS provide

    Security
    backups
    index updating
    enforcement of referential integrity
    facilities to update and query the database

    257

    client side processing

    Client Processing is where webpages use JavaScript to validate data before it gets sent to the sever for further validation.

    258

    Association LAW (OR)

    A∨(B∨C)=(A∨B)∨C= A∨B∨C
    A OR (B OR C) is the same as (A OR B) OR C is the same as A OR B OR C

    259

    Solid-State examples

    USB pens and SD cards

    260

    advantages of peer-to-peer

    -cheap to set up and maintain
    - easy sharing

    261

    Algorithm for deletion into a stack:

    1. Check to see if the stack is empty
    2. If the stack is empty report an error and stop
    3. Copy the data item in location pointed to by the stack pointer
    4. Decrement the stack pointer

    262

    conjunction

    AND

    263

    Atomicity

    a change to a database is either completely performed or not performed at all. A half-completed change MUST NOT be saved back to the database.

    264

    integer

    any positive or negative whole number e.g. 3, 0, -14

    265

    how to normalise a number:

    1. see how many places the binary point has to move so the number starts 01 or 10
    2. store this number in the exponent and then new format of the number in the exponen

    266

    Fibre Optic Cables

    newer, faster and high-capacity

    267

    Code generation

    (stages of compilation stage 3)
    the syntax tree is converted into object code

    268

    Advantages of a client-server network

    - Security is better since all files are stored in a central location
    - Back ups are done centrally so individual users do not need to back up
    - data and resources can be shared

    269

    Algorithm for insertion into a queue:

    1. Check to see is the queue is full
    2. If the queue is full report an error ad stop
    3. Insert new data item into location pointed to by the head pointer
    4. Increment the head pointer and stop

    270

    Hardware interrupt

    - shut down triggered by user pressing on/off button
    - memory parity error (when comparisons don't match)
    - internal clock triggers suspending a running process

    271

    why is manageable code important

    easy to read, debug and easy to maintain

    272

    logic gates in a half adder

    XOR (to the sum)
    AND (to the carry)

    273

    application layer

    (1) Packages data and passes it on to the transport layer.

    274

    Object Orientated languages examples

    C++ and Java

    275

    The Computer Misuse Act

    makes unauthorized access to computer systems illegal:
    The intent to commit or facilitate commission of further offences with intent to impair the operating of a computer

    276

    virtual memory

    when the main memory is almost full sections which are less frequently used are stored on the hard disk to free up RAM space

    277

    first normal form

    1. Eliminate duplicate columns
    2. Get rid of any groups of repeating data
    3. Identify the primary key
    4. Separate out any attributes which are not atomic into separate attributes

    278

    Solid-state storage disadvantages

    Expensive
    limited lifespan - each section can only be written to a set number of times

    279

    Operating System

    software that manages the computer; it manages the hardware, software, security and the user interface

    280

    LIFO

    last in first out

    281

    what happens when a search engine indexes a page

    crawlers traverse the web following links and checking each word in the document. It adds an index entry for the page alongside the words position on the page.

    282

    three types of secondary storage

    magnetic, optical, solid-state

    283

    Method of capturing data (Automated)

    barcode readers, scanners, sensors, magnetic ink character recognition, smart card readers

    284

    4 types of system software

    OS, utility, libraries, translators

    285

    JPEG

    joint photographic experts group, losy compressed form of graphics storage

    286

    X∨0 =

    X

    287

    SQL

    SQL is a language which allows for fast, efficient querying and reporting of vast amounts of data held in a relational database. It is a very high-level language.

    288

    Referential Integrity

    Referential Integrity is where table relationships must always be consistent. Any foreign key field must agree with the primary key that is referenced by the foreign key. Thus, any changes to the primary key field must be applied to all foreign keys in another table, or not at all.

    289

    Pre-emtive Algorithms

    based on priority so if one instruction is executing it can be stopped for another instruction to start processing

    290

    Dictionary Coding

    Dictionary coding is when an index is built where every data item in the file is recorded along with an indexed reference. The final compressed file will just consist of the dictionary index along with the sequence of occurrences needed to recreate the original file.

    291

    more bits in the mantissa...

    improves the accuracy but reduces the range

    292

    RISC

    reduced instruction set computing. Small Instruction set where each instruction is performed in one clock cycle.

    293

    magnetic storage positives

    cheap large capacity

    294

    OR

    if both inputs are true or one input is true the the output is true else the output is false

    295

    Advantages of the waterfall model

    - Everyone on the project is very clear on their responsibilities at each stage.
    - Simplicity
    - Easy to see if programming is running to schedule

    296

    limitations of half adders

    - can only add one bit numbers
    - only two inputs, the carry from a previous addition can't be incorperated

    297

    Atomic

    data is in its lowest level of detail and cannot be split into separate attributes

    298

    Malicous Software

    is software that annoys users or damages their data. For example, Worms, Viruses, Trojans, Spyware and ransomware.

    299

    XML

    extensible markup language, text based means of describing data.

    300

    types of application software (12)

    word processors
    desktop publishing programs
    spreadsheets
    database management
    Slideshow and presentation
    Multimedia and video editing
    photo and graphics manipulation
    communications, chat and IM
    social networking
    email clients
    web browsers
    Gaming

    301

    real (floating point)

    a positive or negative number with a fractional component e.g. 0.002 or -1.98

    302

    CISC advantage

    simpler software
    more likely to have a single instruction to carry out an action, larger instruction sets
    works better with more intensive tasks

    303

    Data integrity is the state of data being

    as intended and accurate

    304

    disadvantages of peer-to-peer

    - no central backing up
    -slower performance
    -bad security

    305

    CSS identifiers vs classes

    and identifier can only be used once on one element but classes can be used on multiple elements

    306

    SIMD

    (parallel processing, single instruction multiple data) a single processor carries out an instruction on multiple data

    307

    GPU uses

    graphics, gaming, AI(machine learning), data analysis

    308

    Multi-User Operating System

    Allows multiple users to use the system and its resources simultaneously.

    309

    Drawbacks of packet switching

    - protocols are complex and expensive
    - packets may be lost
    - not neccessarily secure

    310

    Variable

    a name refer to a particular memory location that is used to store data. The value of the data held in that memory location is not known when the program is written and can change while the program is running

    311

    Serialisation

    Serialisation ensures that transactions do not overlap in time and therefore cannot interfere with each other or lead to updates being lost

    312

    ASCII

    American Standard Code for Information Interchange

    313

    three categories of programming languages

    procedural
    Object Orientated
    Assembly

    314

    X∨¬X=

    1

    315

    Proxies

    A proxy ensures there is no direct physical connection between a single user and a remote source.

    316

    disadvantage of server side processing

    - can be slow
    - pages have to be refreshed often to keep up to date

    317

    Hubs

    connects nodes together by broadcasting a signal to all possible destinations. The correct destination will accept the signal

    318

    Association LAW (AND)

    A∧(B∧C)=(A∧B)∧C= A∧B∧C
    A AND (B AND C) is the same as (A AND B) AND C is the same as A AND B AND C

    319

    difference between paging and segmentation

    pages are a fixed size, segments are different sizes
    pages are made to fit sections of memory, segments are complete sections of programs
    pages are physical divisions, segments are logical divisions

    320

    Embedded operating systems

    Washing machines, vending machines, car engine systems, traffic lights, pay and display machines

    321

    Star Topology

    an arrangement where a central node or hub provides a common connection point for all other nodes.

    322

    what does security keeping data safe from?

    - accidental or deliberate loss
    - malicious access

    323

    Bus Topology Disadvantages

    Main cable is a single point of failure
    Limited cable length
    Performance degrades with heavy use
    Poor security

    324

    What does the width of the address bus determine

    the maximum possible memory addresses of the system

    325

    Lossless Compression

    Reduces the file size but allows the original data be perfectly reconstructed from the compressed data. Actual data is still removed however the data is encoded in such a way that the original can be recreated.
    Less effect at reducing file size than lossy.

    326

    drawbacks of open source software

    - can be less user friendly/less easy to use
    - less support available
    - people may exploit failures maliciously before they are fixed

    327

    Shortest job first (SJF)

    Jobs are sorted in the ready queue according the estimated processor time needed

    328

    advantages of client side processing

    -Allows for more interactivity by immediately responding to a users' action
    -Removes potentially unnecessary processing from the server

    329

    Ring topology

    an arrangement where on node is connect to two others to form and ring.

    330

    tree

    a simple connected graph with no cycles

    331

    Primary key

    A field that uniquely identifies each record

    332

    Secondary Key

    Any field which isn't a primary/composite key which can help make a query more efficient

    333

    Disadvantages of rapid application development

    - doesn't scale well

    334

    Searching an item in a hash table:

    1. Feed the key to the hash function
    2. Go directly to array index (HashValue)
    3. If the value is equal to the value that you’re searching for then output the value
    4. Else follow the linked list in sequence until you find the value and output the value

    335

    Input instruction

    INP

    336

    1.0

    negative

    337

    Data Bus

    A bi-directional path for moving data and instructions between system components

    338

    GPU

    Graphical processing unit.
    used for rendering graphics and processing many parallel streams of data at the same time.

    339

    uses of linked lists

    1. Implementing undo functionality
    2. Dealing with browser cache
    3. Helping with operating system job queues

    340

    store instruction

    STA

    341

    RIPA Grants rights to:

    -Demand ISPs provide access to a customer's surveillance
    -Demand ISPs fit equipment to facilitate surveillance
    -Demand access be granted to protected information
    -Prevent existence of such interception activities being revealed in court

    342

    program branch result

    the next instruction held in the PC is not carried out

    343

    pipelining

    overlapping stages in the fetch-execute cycle.
    fetching the next instruction while the first instruction is being decoded

    344

    example of input AND output device

    touch screen or games controllers

    345

    Embedded Operating Systems

    a computer system that forms part of a device such as a washing machine or car

    346

    Harvard architecture

    - instructions and data are stored in separate memory units
    - instructions and data are each served by their own buses
    - allows for pipelining

    347

    CMA year

    1990

    348

    Composite Key

    A unique identifier made from different fields

    349

    positives of databases?

    - provide security
    - provide automatic backup
    - enforce data integrity rules
    - control data redundancy
    - provide users with controlled access to data they need

    350

    Superclass

    the original class and its code

    351

    pipelining advantages

    improves efficiency

    352

    combine rows from multiple rows

    JOIN

    353

    What does a bitwise right shift do?

    divides the number by 2.

    354

    Overflow

    If the result of a binary addition is greater than 255, an overflow error occurs, where the most significant bit requires a ninth bit (Put it in brackets)

    355

    negatives of multiple cores

    complicated circuitry (more expensive)
    doesn't always improve performance

    356

    by changing the position of the binary point you can...

    increase the size of the number
    increase the accuracy of the number

    357

    MIMD

    multiple instruction multiple data, multiple instructions are carried out on multiple data using multiple cores

    358

    Local Area Network (LAN):

    method of connecting computers together in a small geographical area. All the hardware and infrastructure is owned by the business/ organisation that uses it.

    359

    Benefits of Open source software

    - usually free
    - users are free to amend the source code and tailor the program to their needs
    - not constrained by commercial considerations
    - many people are continuously finding and fixing bugs

    360

    instantiation

    the process of creating an object from a class template

    361

    Uses of Multi-tasking operating systems

    desktops and smart phones

    362

    Entity Relationship Modelling

    when the relationships between tables are shown in abstracted view.

    363

    CISC disadvantages

    more complex circuitry/hardware
    Single machine instruction takes multiple machine cycles to carry out
    greater energy consumtion
    can't support pipelining
    more silicon require to make
    physically larger in size

    364

    How does Java use virtual machine?

    the virtual machine execute intermediate code (Java Byte code)

    365

    Half adder outputs/inputs

    inputs: the two bits to be added
    outputs: the result and the carry

    366

    Algorithm for deletion/reading from a queue:

    1. Check to see if the queue is empty
    2. If the queue is empty report an error and stop
    3. Copy data item in location pointed to by the tail pointer.
    4. Increment tail pointer and stop

    367

    Writing an alert box

    alert(“Hello World”);

    368

    Search engine indexing

    Uses web crawlers and relies of databases of indexes, and uses those indexes to find more databases forming links

    369

    divides the page into segments allowing for improved styling

    370

    input device

    any device which allows you to get information from the outside world into a computer system so that it can be stored in a digital form

    371

    utility programs examples

    - Disk defragmenter
    - Automatic backup
    - Automatic updating
    - Virus checker
    - Compression software

    372

    Input/output interrupt

    - Buffer almost empty
    - Signals the completions of data transfer between devices

    373

    X∨X=

    X

    374

    First come first serve (FCFS)

    the processes are executed in the order they arrived
    if all the processes take along time all the others must wait

    375

    how does the PC know where to return to in the previously executing program after services an interrupt

    by putting instructions on a stack

    376

    how to use a form tag




    377

    changing the contents of an HTML element JavaScript

    chosenElement = document.getElementById(“example”);

    chosenElement.innerHTML = “Hello World”;

    378

    writing directly to a document JavaScript

    document.write(“Hello World”);

    379

    Benefits of packet switching

    - efficient use of the network
    - can be rerouted to avoid problems in the network
    - data is transmitted immediately

    380

    JavaScript Clientside

    Used to process data on clients computer which allows erroneous data validation on client side which is quicker and relieving on a server side.

    381

    Normalisation

    Organising the attributes and relations of a relational database to minimise redundancy

    382

    Firewalls

    a program that blocks unauthorised access onto a network by inspecting packets to find the port they are attempting to access through.
    If the port is blocked then the packet is rejected.

    383

    Flip flop

    elemental sequential logic circuit that can store one bit and flip between two states

    384

    Server side processing

    data is processed on server side as they can process bigger amounts and take the strain off clients

    385

    Encryption

    A method of transforming data into an unintelligible way so that it cannot be read by unauthorised individuals.

    386

    Advantages of rapid application development

    - flexible to changes
    - quick
    - simple
    - can reduce risk

    387

    Input/ Output interrupts

    buffer nearly empty
    signal the completion of data transfer to/from a device

    388

    translator

    any program that converts source code into machine code. e.g. interpreters, compilers and assemblers

    389

    Disadvantages of Networks

    The user can become dependent on the network
    If the network stops operating then it may not be possible to access various resources
    Efficiency of a network can be very dependent on a network manager
    It is difficult to make a network of computer secure for hackers and outside threats
    As traffic increases on a network the performance can degrade

    390

    branch if zero instruction

    BRZ

    391

    RISC disadvantages

    complicated software
    more machine code (not as many instructions)
    lower clock speed, not good with complicated tasks

    392

    advantages of server side processing

    - doesn't require plugins or browser scripting technology
    - more secure
    -reduces loading time

    393

    third normal form

    1. Check the data is already in 2NF
    2. Check there are no non-key-dependencies

    394

    Disk defragmentation

    programs which attempt to consolidate the spilt files and free space. therefore reading and writing files becomes more efficient.

    395

    Trojan

    A Trojan is software that misleads the user of its true intent. Often, they serve to open up back doors in your computer.

    396

    Negation

    NOT

    397

    Layering

    the principle of dividing a complex system into separate slices of functionality

    398

    4 types of application software

    off the shelf, custom written, proprietary and open source

    399

    record

    an un-ordered data structure which is accessed through an attribute. It can store many different data types.

    400

    capacity of optical

    700MB - 50GB

    401

    branch if zero or positive instruction

    BRP

    402

    Memory Address register (MAR)

    stores the address of instructions and data that need to be fetched from or sent to memory

    403

    Advantages of using byte code interpreters

    - Achieve platform independence
    - Acts as an extra security layer between program and computer

    404

    Bus topology advantages

    Inexpensive to set up
    Devices can easily be added
    Good for small networks

    405

    pipelining disadvantages

    only good if you can predict subsequent instructions. If the wrong instruction is fetched it has to be thrown away wasting time.

    406

    create a new table SQL

    CREATE TABLE tblName

    407

    Why is paging not efficient

    it does not take into account what the instructions in each page are doing

    408

    What is a mask?

    A mask allows you to isolate, extract, toggle and set bit values in a sequence of bits.

    409

    Clock speed Unit

    Hertz (usually gigahertz)

    410

    Port

    A port is used to alert a specific application to deal with data sent to a computer. These are used by protocols to specify what data is being sent.

    411

    Buses

    the communication channels between the CPU and the memory and other components.

    412

    Flash

    multimedia platform for creating and displaying graphics (replaced by HTML5)

    413

    Inserting items into a binary search tree:

    look at each node starting at the root. If the new value is less than the value at the node, move left otherwise move right. Repeat this for each node arrived at until there is no node. Insert a new node at this point and enter the data.

    414

    What does ASCII stand for

    American Standard Code for Information Interchange

    415

    Negatives of Symmetric encryption

    There is a security risk as the key may be intercepted or the process of creating the key may be duplicated meaning the data can be decrypted by a third party.

    416

      unordered list

      417

      Non pre-emptive algorithms

      - First come first serve
      - shortest job first

      418

      Benefits of asymmetric

      - no movement of keys, more secure
      - can be used for digital signatures

      419

      data storage instruction

      DAT

      420

      binary search tree

      dynamic data structure which can grow and shrink during a programs execution. It allows for efficient sorting, searching and retrieval of data.
      a binary tree can have 0, 1, or 2 children only.

      421

      Optical storage disadvantages

      slow access speed
      the surface of the disk degrades over time
      scratches can corrupt data

      422

      What does an OS provide?

      - User interface
      - Memory Management
      - Interrupt handling
      - Processor scheduling

      423

      writing to a file

      myFile = openWrite(“sample.txt”)
      myFile.writeLine(“Hello World”)
      myFile.close()

      424

      Why Do RISC processors result in increased battery life

      - smaller instruction set
      - fewer transistors/ less complex circuitry
      - less power required

      425

      Negatives of increasing clock speed

      more heat generated meaning computers must be cooled (either with heat sync/fan or water/oil cooling)

      426

      Timer Interrupts

      Triggered regularly by a timer, to indicate that it is the turn of the next process to have processor time- this allows for multi tasking

      427

      AND

      if both inputs are true the output is true else the output is false

      428

      Method

      a subroutine associated with an object

      429

      Wide Area Network (WAN:

      a method of connecting remote computers or networks. Typically made up of smaller LANs which have been connected together.

      430

      ROM

      non-volatile read only memory embedded into the motherboard of a computer and used to hold important instructions the computer needs for starting up

      431

      examples of system software

      Operating system, Utility Program, Library Program, Translators.

      432

      why can assembly code for one processor not work for another processor

      each type of processor has its own unique instruction set

      433

      Device drivers are...

      hardware dependent and OS specific

      434

      Database

      Databases are structured, persistent collections of data.

      435

      Uses of RISC

      used in most smart phones and tablets based around an ARM processor

      436

      boot up process of a computer

      - POST is run
      - clears anything in the registers
      - loads the address of the first instruction of the boot program into the PC
      - the boot program checks for start-up instructions on the BIOS
      - The OS kernel is loaded

      437

      What is bitwise manipulation useful for?

      - Compression Algorithms
      - networks (protocols. routing packets)
      - multiplication and division

      438

      Wireless Access Point

      use wireless to connect a node to a WiFi network avoiding the need for lots of physical caballing

      439

      X∧1=

      1

      440

      fixed point binary

      positive of the binary point is fixed on the number line

      441

      preorder traversal

      1. Visit the root
      2. Traverse the left sub-tree
      3. Traverse the right-sub-tree

      442

      Parallel processing/concurrent processing

      multiple processors working at the same time

      443

      Agile Modelling

      - Methodology which stages of software are not completed in a linear sequence
      - Throughout the process feedback is obtained which changes the software
      - It is a smaller version of spiral

      444

      Advantages of the spiral model

      - good from projects with high levels of risk
      - suitable for large scale problems

      445

      benefits of symmetric

      - encrypted very quickly
      - simple and easy

      446

      Co-processor

      a processor designed for specific purposes which can carry out specialised tasks more quickly than a regular microprocessor. execute concurrently with the main CPU

      447

      width CSS property

      width

      448

      advantage of normalisation

      it stores the most accurate version of that number.

      449

      Load instruction

      LDA

      450

      while loop pesudocode

      while condition=
      code
      endwhile

      451

      Virtual storage

      (cloud storage) when data is stored over the internet on cloud storage instead of on local storage device

      452

      Von neumann architechture

      - instructions and data share the same memory space
      - instructions and data served by the same system bus
      - instructions and data are stored in the same format
      - single CU and ALU

      453

      Disjunction

      OR

      454

      Procedural programming languages

      programming languages where the user gives step by step instructions of what to do

      455

      automated decision making

      computers make decisions and take actions based on sets of pre-defined rules and parameters without human involvement

      456

      compression

      programs which attempt to reduce the amount of physical space that files take up when they're stored

      457

      system bus

      collective term for address, data and control bus

      458

      RIPA year

      2000

      459

      Flat File

      single table database. It is inefficient as it is difficult to query and leads to data redundancy which can cause errors.

      460

      Shortest remaining time (SRT)

      The ready queue is sorted on the estimated time to complete the process. If the remaining time of a running process is longer than a new process the new process will be moved to the running state

      461

      Bitwise shifts can be used ...

      to change numbers quickly

      462

      digital signature

      hash total is encrypted using the users private key. If the receiver can decryptit using the senders public key they know that the message is authentic

      463

      Uses of Multi-user operating systems

      schools and offices

      464

      censorship

      the deliberate supression of material, either in the form of what can be published or what can be accessed

      465

      Benefits of high level code (over assembly)

      - optimisers may make code more efficient
      - intuitive and easier to write
      - can be recompiled for different architechtures
      - less code is written (shorter programs)

      466

      Internal css vs external css

      internal is within the document external is linked to html code

      467

      inorder traversal

      1. Traverse left sub-tree
      2. Visit the root
      3. Traverse the right sub-tree

      468

      Syntax analysis

      (stages of compilation stage 2)
      the syntax is checked against the rules and an abstract syntax tree is created
      if any code breaks the syntax rules an error is generated

      469

      Condition between two values SQL

      WHERE x BETWEEN a AND B

      470

      The Regulation of Investigatory Powers Act

      gives certain bodies the right to monitor communications and internal activity. It was made due to modern threats from criminals and terrorist organizations.

      471

      flip flop logic gates

      Two NAND gates with two inputs. The result of of each is the second input for the other.

      472

      Benefits of assembly code (over high level)

      - efficient as the code is more specifc
      - direct control of hardware
      - good if no compilers/interpreters installed
      - good if limited memory

      473

      DIV

      integer division (rounds down)

      474

      Round robin (RR)

      each process is allocated a specific amount of time known as a time slice or quantum. if a process is not complete at the end of the time slice it returns to the back of the queue, so the next process can have its turn.

      475

      Pre-emptive algorithms

      - Round Robin
      - Shortest Remaining Time
      - Multi-level feedback queue

      476

      Multi-level feedback queue

      uses multiple queues based of the priority of the process.

      477

      Uses of Hashing

      - generating disk address
      - storing and checking passwords

      478

      postorder traversal

      1. Traverse the left sub-tree
      2. Traverse the right sub-tree
      3. Visit the root

      479

      full image tag

      480

      Requirements specification

      A document listing all the functionality the system should have

      481

      X∧¬X=

      0

      482

      external storage examples

      DVDs, CDs, Blue-ray, USB pens, SD card, Portable solid state drive, Mass storage tape, cloud storage.

      483

      Meta tags, keywords, descriptions

      Search engines look for this to find the content that matches your search

      484

      the tag to include JavaScript code

      485

      Absorbtion Law AND

      A∨(A∧B) = A
      X OR (X AND Y) is the same as X

      486

      iteration

      do a set of statements again and again (looping)

      487

      delete rows of a table

      DELETE
      FROM
      WHERE

      488

      Bottleneck data bus

      A wider bus can transmit larger values/ more bits per instruction

      489

      Encapsulation

      the protection of attributes and methods of an object so that they can't be accessed or altered by other objects. (keyword - private)

      490

      Where is RAD used?

      good for when the project requirements aren't completely clear from the outset

      491

      Multi-user operating system

      more than one user is able to use the computer at one time. The operating system manages user preferences. Tis is often used for servers.

      492

      Subclass

      the new class which inherited from the superclass

      493

      condition controlled time

      repeat a set number of statements until a condition is met

      494

      mantissa

      the actual number you want to store

      495

      Application Programming Interface (API)

      a set of tools that can be used for building software applications.

      496

      Where is extreme programming used?

      good for when the requirements change

      497

      Algorithm for insertion into a stack

      1. Check to see if the stack is full
      2. If the stack is full report error and stop
      3. Increment the stack pointer
      4. Insert new data item into location pointed to by the stack pointer and stop

      498

      Accumulator

      stores the result of calculations made by the ALU

      499

      scheduler

      A program that manages the amount of time different processes have in the CPU

      500

      Control Unit

      Control Unit is a register in the CPU that controls and co-ordinates the activity of the CPU. Control signals are sent along the control bus between the control unit and the other components of the computer.

      501

    • The individual parts of the list





      502

      example uses of flip flops

      - in registers
      - static RAM

      503

      distributed operating systems

      combing the processing power of multiple computers for a single task across a network. The OS controls and co-ordinates the computers, presenting it to the user as if it were a single system.

      504

      heading text

      505

      Spiral Model

      - designed to try and manage risk. made of four stages:
      1. determine objectives
      2. Identify and resolve risks
      3. development and testing
      4. plan next iteration

      506

      Antivirus utility software

      programs which help to detect and remove malicious programs which are often designed to harm the computer.

      507

      ROM acronym

      read only memory

      508

      segmentation

      when memory is split up however the logical divisions of a program are kept together, rather than having fixed page sizes

      509

      CSV (Comma Separated Value)

      A text file/format with values separated by
      commas

      510

      Backing Up

      programs which allow for manual or automatic backing up of files onto another disk, on the existing computer system, to a removable device such as DVDs or CDs, to a network file server or to a cloud based storage system online

      511

      order of main HTML tags








      512

      RAM

      fast read-write volatile memory that stores the data and programs the computer is currently using e.g. OS, Programs currently in use, data that the programs are accessing

      513

      Memory write signal

      causes data on the data bus to be written into the addressed location in RAM

      514

      Purpose of Compression

      1. Reduce download times
      2. Reduce requirements on file storage
      3. Make best use of bandwidth

      515

      PDF

      portable document format, to display documents exactly as intened

      516

      d page rank

      The damping factor to prevent the rest of the equation from having too much influence

      517

      ¬(¬A) =

      A

      518

      relationship between the DNS server and IP addresses

      a registered domain name is held on the DNS server. The corresponding IP address to a searched domain name is loaded on the users computer.

      519

      Worm

      A Worm is a standalone program that does not require a user to run it in order for it to spread.

      520

      Disadvantages of the waterfall model

      - The absence of user feedback
      - not suitable for large projects
      - Requirements must be very well understood

      521

      positives of multiple cores

      may speed up processing

      522

      Arithmetic Logic Unit

      Carries out calculations and logic (Comparisons of binary)

      523

      Control signals

      - Memory read
      - memory write
      - bus request
      - clock signal

      524

      by default how are parameters passed?

      by value

      525

      Boolean

      Any true/ false data types which often represent logical situations

      526

      closed source software

      software which is supplied pre-compiled. The source code is not available and often copyrighted, also known as proprietary software
      e.g. microsoft word

      527

      GIF

      graphics interchange format, lossless compressed image file format

      528

      Transport Layer

      (2) Makes and breaks connections with routers

      529

      Registers

      Registers are small storage locations used to hold data temporarily. They have high read and write speeds.

      530

      Deleting an item in a hash table:

      1. Feed in key to hash function
      2. Go directly to array index (HashValue)
      3. If the value is equal to the value you’re searching for then mark as empty
      4. Else follow the linked list in sequence until you find the value then mark as empty and update the free pointer in the linked list.

      531

      persistent

      the data remains for as long as its required

      532

      Transaction Processing

      Transaction processing is any information processing which is divided into individual, indivisible operations each operation must secede or fail as a complete unit.

      533

      Order Queried data SQL

      ORDER BY

      534

      Where is the spiral model used?

      Used in large scale projects

      535

      MAN

      metropolitan area network

      536

      need for secondary storage

      Can retain contents when the computer's power is turned off. This includes the Hard drive, optical media and solid state storage.

      537

      reading from a file

      myFile = openRead(“sample.txt”)
      x = myFile.readLine()
      myFile.close()

      538

      Camera/eye tracker

      Move/blink to send signal

      539

      Object

      Instance of a class

      540

      immutable

      structure and data cannot be changed at runtime

      541

      relational databases

      multiple tables linked together

      542

      data bus width

      same as the computers word size

      543

      indexing

      used to quickly access and locate data in a table

      544

      When is Bitwise ANDing useful?

      useful for TCP/IP and routing

      545

      nodes with no sub-nodes

      leaf-nodes or terminal nodes

      546

      Check if an attribute is similar to a given value SQL

      LIKE

      547

      Decode

      The contents of the CIR are sent to the CU and divided. The Opcode tells you the instruction to be carried out and the operand stores the address of any data which might be needed, the operand is sent to the MAR and the data is fetched from memory and stored in the MDR

      548

      Loaders (dynamic linking)

      compiled versions of libraries are stored by the computer and the operating system links the code directly into the program when it is needed reducing the size of programs. Loaders are needed to include or load the libraries into memory ready for use.

      549

      composite key

      A composite key is a combination of two or more columns in a table that can be used to uniquely identify a row.

      550

      Advantages to Peer-to-peer networking

      - Cheap
      - Enables users to share resources
      - not difficult to maintain

      551

      assignment operator

      single equals, sets the value on the right equal to the value on the left

      552

      Interrupt register

      generates and detects interrupts

      553

      constructor method

      signified by the key word new, initiated instantiation

      554

      lexical analysis

      (stages of compilation stage 1)
      white space is removed
      remaining code is turned into tokens
      a symbol table is created (including variables, data types and scope)

      555

      Isolation

      a transaction must not be able to be interrupted by anther transaction. The transaction must occur in isolation so that other users or processes cannot have access to the data concerned.

      556

      assembly language

      a low level language represented by mnenomics which represents the machine code.

      557

      more bits in the exponent...

      improves the range but reduces accuracy

      558

      constant

      name used to refer to a fixed value. The value is set when the code is written and cannot change while the program is running

      559

      RISC advantages

      very simple hardware/circuitry less silicon needed
      each instruction is a single machine cycle therefore pipelining can be used to improve performance
      lower energy consumption (can go into sleep mode)

      560

      collision (hash table)

      when the same hash value is given by two different keys

      561

      advantages of Client-Server

      -User IDs, passwords and access levels centrally controlled
      -Backup is centralised and usually automated
      -No access to other users’ files

      562

      breadth first traversing

      It starts at the root node, and visits all of the neighbor nodes at the present depth prior to moving on to the nodes at the next depth level.

      563

      negative of increasing cache size

      expensive

      564

      Multitasking operating system

      can run multiple programs simultaneously

      565

      defines a form that is used to collect user input

      566

      function

      a sub-routine that make take one or more parameters and ALWAYS returns a value

      567

      Full adder inputs/outputs

      inputs: the two bits to add, the previous carry bit
      outputs: the result, the carry

      568

      string

      any combination of letters, symbols, numbers, characters or control characters e.g. Hello, £4.56

      569

      magnetic storage examples

      magnetic tape, floppy disks hard disk drives

      570

      optical storage

      data is written to the surface of a reflective disk using pits (depressions) and lands. A laser beam passes over the surface of a land and the light beam reflected back is interpreted as binary values.

      571

      Uses of the internet

      communication, information, entertainment, education, financial transactions, controlling devices

      572

      tags

      mark out elements on a web page to indicate to a browser how to display or process an element

      573

      Gateway

      A Gateway is required where data is travelling from one network to another using different protocols

      574

      clustering

      when you store the data in the next available space of a hash table increasing the chance of collisions

      575

      Distrubuted Operating Systems

      allows multiple computers to work together on a single task

      576

      Positives of increasing clock speed

      you can carry out more instructions in a given time; improved performance

      577

      priority

      given to an interrupt to determine how fast they are executed

      578

      normalising:
      moving the point to the right

      - exponent

      579

      HTTP

      Hypertext Transfer Protocol – used by web servers and browsers to transfer webpages.

      580

      operand

      the data the instruction applies to

      581

      Star Topology advantages

      Easy to isolate problems
      Good performance
      More secure is a switch is used a data is sent only to the recipient

      582

      Distribution LAW (OR)

      A∧(B∨C)=(A∧B)∨(A∧C)
      A AND (B OR C) is the same as (A AND B) OR (A AND C)

      583

      depth first traversing

      follows one path down to a child node, it the visits this then backtracks to the next level then moves down to the next child node.

      584

      Solid-State storage advantages

      Durable
      No moving parts
      fast access time

      585

      application software

      any software which allows a user to carry out a task on a computer

      586

      Assembly code

      A set of simple instructions displayed as Mneumonics which is unique for each processor/hardware.

      587

      Internet Layer

      (3) provides links across different network types.

      588

      magnetic storage

      where metal disks called platters are magnetised. a read-write head moves very close to the platter and is able to detect and modify the magnetic properties of the platter.

      589

      computer program

      a series of instructions that are executed one after another.
      follow the pattern: INPUT -> PROCESS -> OUTPUT

      590

      Bus Topology

      an arrangement where nodes are connected to a central communication channel. Each end of the backbone is connected to a terminator. Each node is passive and data is sent in one direction at a time only

      591

      Software interrupts

      - Arithmetic overflow
      - Illegal instruction encountered

      592

      Advantages of extreme programming

      -Acknowledge user input
      - Useful for when there is a danger of getting sidetracked by suggested improvements
      - cost and time saving
      - constant feedback
      - Has a very high emphasis on programming so quality of end code likely to be very high.

      593

      Where is agile methodologies used?

      large projects where there is a lot of collaboration

      594

      random files

      which allow you to access any item without having to search through the file from the start

      595

      Foreign key

      a foreign key is a field in one table that uniquely identifies a row of another table

      596

      Circuit Switching

      Circuit Switching: a complete circuit or route between two nodes is established before transmission begins. Once the rout is established all data follows this route until transmission is complete.

      597

      assembler

      converts low level assembly language directly into machine code.
      this is a one to one relationship and is processor specific

      598

      Why is it necessary to have a variety of programming languages?

      - different languages suit different jobs
      - developers prefer certain languages

      599

      Record/Tuple

      the rows (a data set that applies to one item)

      600

      inorder dot

      below

      601

      FTP

      File Transfer Protocol – Used by clients and servers to upload and download files across the internet

      602

      switch/case pseudocode

      switch condition:
      case “A”:
      code
      case “B”:
      code
      default:
      code
      endswitch

      603

      interrupt service routine

      when the processor receives an interrupt and must stop what its doing in order to service the interrupt and run that code.

      604

      polling

      the CPU checks with each device if it needs its attention.
      This is inefficient and wastes time as some devices will not want attention when called upon.

      605

      Router

      devices which are used to connect networks. they receive data packets from one network and based on the address on the packet forward them of

      606

      styling of elements CSS

      h1{
      color:blue;
      }

      607

      MAC Address

      identifier that is permanently added to a device by the manufacturer

      608

      dense graph

      A graph which has more edges in relation to vertices

      609

      delete full tables SQL

      DROP TABLE table_name;

      610

      device driver

      software that tells the operating system how it can communicate with a device

      611

      Searching for an item in a linked list:

      1. Set the pointer to the start value
      2. Repeat:
      a. Go to node (pointer value)
      b. If the data at the node is the search item
      i. Output the data and stop
      c. Else
      i. Set the pointer to the value of the next item pointer at the node
      d. Until pointer = 0
      3. Output data not found

      612

      Run Length Encoding

      Run length encoding is used when there is repeated redundant data. It stores the item once and then an index with how often the item is repeated.

      613

      Phishing

      Phishing is using email to manipulate a victim into visiting a fake website and giving away personal information.

      614

      Control Bus

      A bi-directional bus to transmit command, timing and specific status information between system components

      615

      Rapid application Development

      - user is shown a prototype and gives feedback to inform how the prototype is further developed until the final project is complete

      616

      Emulators

      provide an illusion to a user/program that it is running on its native hardware when in fact it is on an entirely different machine

      617

      purpose of operating systems: providing a user interface

      allowing users to interact with applications. This may be graphical (GUI and WIMP), menu driven or command line

      618

      The Waterfall Lifecycle Model

      - a sequence of stages. each stage can only start after the previous one is complete.
      - it possible to go back stages however you can't skip ahead
      - user involved once at the beginning

      619

      Uses of symmetric encryption

      Used when the same person is accessing and saving data e.g. for backing up

      620

      breadth first traversing uses a

      queue

      621

      Disadvantages of a client-server network

      - expensive to install and manage
      - professional IT staff are needed to maintain

      622

      Pagerank equation

      PR(A) = (1-d) + d (PR(T1))/C(T1) + ... + PR(Tn)/C(Tn))

      623

      Client-Server Model:

      one device (the client) requests services from another device (the server).

      624

      Flip Flop use

      used as a memory cell to store the state of a bit

      625

      count controlled loops

      repeat a set number of statements a fixed number of times

      626

      how does circular shifting work?

      you shift either way and the left over bit circles back around to the beginning.

      627

      BIOS acronym

      Basic Input Output System

      628

      border colour CSS property

      border-color

      629

      AND (*)

      630

      Special pupose application software

      A software that preforms single specific tasks. e.g. payroll, hotel booking systems or browser software

      631

      Distribution LAW (AND)

      A∨(B∧C)= (A∨B)∧(A∨C)
      A OR (B AND C) is the same as (A OR B) AND (A OR C)

      632

      magnetic storage negatives

      slow access speed
      moving parts make it vunerable

      633

      index sequential files

      for very large data sets the order of the index is maintained so the data can be accessed in an order

      634

      What are the two most common character sets?

      ASCII and Unicode

      635

      Why are protocols Important

      allows computers to communicate by ensuring all devices follow rules so they interpret signals in the same way

      636

      Data Protection act

      sets out requirements for the control or storage of individuals personal data.
      In a company the data controller has to control the processing and storage of data based on the data subject.

      637

      virtual memory disadvantages

      it is not efficient.
      time is spent relocating part so program to the hard disk meaning there is less execution taking place, this is known as disk thrashing.
      the CPU can't execute instructions from the Hard disk so instructions must be bought back which is slow and wastes time

      638

      Full adder

      combines two half adders, used to add a series of bits

      639

      Real-time operating systems

      used in safety critical environments such as air crafts or hospital equipment. processes are guaranteed to be executed in a known time frame, there is plenty of redundancy built in so that the system can handle unusual interrupts. The processors never run at capacity.

      640

      A∨ ¬A =

      1

      641

      optical storage examples

      CDs, DVDs, Blue-ray disks

      642

      subtract instruction

      SUB

      643

      similarities between paging and segmentation

      both allow programs to run despite insufficient memory
      both pages and segments are stored in a disk
      both pages and segments are transferred into memory when needed

      644

      queue data structure

      A queue is known as a FIFO structure. A pair of pointers is used to point to the front and back of the queue. If an item is popped from the queue the front pointer points to the item being popped. If an item is pushed onto a queue the tail pointer increments by one and points to the new end of queue.

      645

      Formats of data

      - CSV (Comma Separated Value)
      - XML (eXstensible Markup Language)
      - SQL (Structured Query Language)

      646

      DPA year

      1998

      647

      Network

      an interconnected set of devices

      648

      Bitwise ORing ...

      sets a subset of the bits in the value

      you use 1s where you want to set values and 0s when you want to leave them alone

      649

      Aims of scheduling

      - to provide an acceptable response time to all users
      - To maximise the time the CPU is usefully engaged
      - To ensure fairness on a multi-user system

      650

      IP

      Internet Protocol – used to transfer all packets across the internet between routers

      651

      output instruction

      OUT

      652

      Protocol

      A protocol is a set of rules relating to the communication between devices.

      653

      Advantages of self driving cars

      - safer than a human driver (due to quicker reaction
      speeds etc.).
      - cheaper as no wage to cover.
      - less likely to make mistakes with route

      654

      Paging

      Memory is split up into physical sections which are all the same fixed size

      655

      background colour CSS property

      background-color

      656

      hardware interrupts

      power/reset button is pressed
      memory parity error (corrupt memory)

      657

      Masks can be used ...

      to set and toggle specific bits in a larger sequence.

      658

      Disadvantages of Peer-to-peer networking

      - used for torrent downloading
      - When they all want to be used at once it becomes difficult to share resources

      659

      immediate addressing

      when the value in the operand is the actual value to be used. this means the memory does not need to be searched

      660

      stages of compilation

      Lexical analysis
      syntax analysis
      code generation code optimisation

      661

      Traversing data from linked lists:

      1. Set the pointer to the start value
      2. Repeat:
      a. Go to the node
      b. Output the data at the node
      c. Set the pointer to the value of the next item pointer at the pointer
      d. until pointer = 0

      662

      Library Programs (System Software)

      contains useful functions that are frequently used by programs. Simplifies the process of application development.

      663

      TCP

      Transmission Control Protocol – used with IP to ensure error free transmission and package switching

      664

      Exclusive Disjunction

      XOR

      665

      Libraries

      pre-compiled pre-tested sets of code, often with hundreds of ready to use routines available to the programmer.

      666

      procedure OO pseudocode

      public procedure
      code
      endprocedure

      667

      X∨1 =

      X

      668

      Feasibility study

      the initial investigation that determines whether a project is viable before time and resources are invested into it

      669

      Web Forms

      Enable websites to collect user input. Javascript is used to add behaviours to the script

      670

      Insert data into a table SQL

      INSERT INTO tblName

      671

      Data redundancy

      the unnecessary duplication of data in a database. When updates occur, all the instances of a data item must be changed. This leads to errors and also wastes storage space.

      672

      Positives of increasing cache size

      less time fetching data; improved performance

      673

      role of JavaScript

      the code interactivity into webpages

      674

      Disadvantages of self driving cars

      - May not be able to understand natural speech.
      - May be limited in terms of the roads on which it
      can operate.
      - Vulnerable to hacking.
      - Only as good as the program running it – a bug in
      the code could cause catastrophic accidents.
      - May prioritise safety of pedestrians over that of
      the passenger. (e.g. may take actions that may
      put the passenger at risk to save the lives of
      numerous people outside the car.)
      - No discussion possible with the driver / no
      "human presence" to reassure nervous
      customers.

      675

      fetch decode execute cycle

      PC
      MAR
      Address Bus
      Memory
      Data bus
      MDR
      CIR
      Decode Unit

      676

      font CSS property

      font-family

      677

      Variable length fields

      an element may use a different number of bytes to another element for example a different number of characters.
      Means it only uses the necessary amount of storage

      678

      two types of software

      system and application

      679

      CSS class

      DOT
      .infoBox{
      background-color: green;
      }

      680

      virtual machine

      Where software is used to take on the function of the machine, including executing code or running an OS within another to emulate e.g. when you install windows on OSX

      681

      Fetch

      1. The address of the next instruction is copied from the PC to the MAR
      2. The fetch signal is sent across the control bus. The content of the MAR are transferred across the address bus.
      3. The contents of the memory location stored in the MAR are sent across the data bus and stored in the CIR
      4. the PC increments by 1

      682

      Client-Server Networking

      One or more computers know as clients are connected to a more powerful central computer known as the server

      683

      compiler

      converts high level code to object code.
      this is a one to many relationship and means programs can be distributed without the source code

      684

      storage device

      any computer hardware used for temporary or permanent storage of data. They can be internal or external to a computer.

      685

      indirect addressing

      where the operand contains the address which contains the address where the value can be found.
      useful because it means that the larger addresses in memory can be used to store data.

      686

      nodes lower than the root node

      children

      687

      update attribute SQL

      SET

      688

      turing complete

      a programming language is able to solve all the problems a computer is able to solve.

      689

      flip flop clock diagrams

      on each rising edge of the clock change the result to whatever the input is (it may not need changing)

      690

      Serial files

      • Permanent storage of data
      • Data is stored in the order in which it was entered
      • No order to the data is maintained
      • Useful for storing transactional data and initialisation files

      691

      positives of computers in the workplace

      more effective communications
      removal of humans in construction processes
      shifting skill sets

      692

      insert items into a table

      INSERT INTO table_name (column....)
      VALUES (value...)

      693

      layered operating system

      each layer only interacts with the layer next to it

      user -> application -> operating system -> hardware

      694

      add instruction

      ADD

      695

      get the substring

      stringname.subString(startingPosition, numberOfCharacters)

      696

      Database Management System

      software that handles the data that is stored in secondary storage.

      697

      SQL similar elements

      LIKE

      698

      What determines the format of a machine code instruction

      - the word size
      - the width of the address bus

      699

      branch always instruction

      BRA

      700

      Timestamp ordering

      every object has a read timestamp and a write timestamp meaning if the read timestamps are not the same the DBMS knows another user has accessed the same object

      701

      Processor Scheduling

      The OS can queue up processes for the CPU to make the most efficient use of the computer which gives the illusion of multitasking

      702

      SQL (Structured Query Language)

      A language for creating/querying databases

      703

      3 programming constructs

      sequence, selection, iteration

      704

      RAM acronym

      Random Access Memory

      705

      limitations of arrays

      they can only store one data type
      they're a static data structure

      706

      Benefits closed source software

      - companies have a lot of resources providing security if the program doesn't work, service/support, and a more polished user friendly product

      707

      depth first traversing uses a

      stack

      708

      Sequential Files

      • Store data in order of a key field
      • The order is maintained when new records are added

      709

      four ways of addressing memory in a computer

      immediate
      direct
      indirect
      indexed

      710

      inheritance

      enables new objects to take on the properties of existing objects

      711

      character

      Any single letter, symbol, number, character or control character

      712

      SAN

      storage area network

      713

      Domain Name System Server (DNS sever)

      System thats stores names for IP addressees on a network

      714

      Uses of client-server networking

      File Server holds and manages data for all clients
      Print Server manages print requests
      Web server manages requests to access the web
      Mail server manages the email system
      Database server manages database applications

      715

      Clock speed

      Indicates the number of instructions the CPU can process per second.

      716

      MPEG

      motion picture experts group, a compression standard for audio visual and data files

      717

      SQL query

      SELECT
      FROM
      WHERE

      718

      file managers

      programs which allow users to easily copy, delete, rename and modify files on a computer system

      719

      non key dependency

      where the value of an attribute is determined by the value of another attribute which is not part of the key.

      720

      Attribute/field

      the columns (describes the characteristics of each record)