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Flashcards in Paper 1 Deck (720)
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1
Q

Bitwise XORing…

A

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
Q

Depth First algorithm

A
  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
Q

Encryption

A

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

4
Q

serialisation

A

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

5
Q

Class

A

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

6
Q

how is redundancy used usefully

A

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

7
Q

X∧X=

A

X

8
Q

do until loop pseudocode

A

do
code
until
condition

9
Q

Sequence

A

do one statement after another in the correct order

10
Q

Symmetric Encryption

A

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
Q

NOT

A

reverses the outcome of the expression

12
Q

Byte Scale

A

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

Multiple by 1024 to move up

13
Q

Method of capturing data (Manual)

A

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

14
Q

purpose of operating systems: managing external devices

A

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

15
Q

How are character sets used to represent text?

A

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
Q

Capacity of magnetic

A

640 GB - 1TB

17
Q

clock use

A

synchronise the change of state of flip flop circuits

18
Q

linked lists

A

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
Q

Selection

A

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

20
Q

Peer-to-Peer Networking

A

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

21
Q

disadvantages of Client-Server

A
  • Can be expensive to set up and to manage

- Server is single point of failure

22
Q

how to convert floating point binary to denary

A

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
Q

components of a packet

A

senders address, recievers address, packet contents, sequence number

24
Q

Consistency

A

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

25
Q

clock

A

sequential circuit that changes state at regular time intervals

26
Q

Program Counter

A

stores the address of the next instruction

27
Q

POST acronym

A

Power of self test

28
Q

X∧0=

A

0

29
Q

relationships

A

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

30
Q

in two’s complement the sign is stored in

A

the most significant bit

31
Q

direct addressing

A

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

32
Q

preorder dot

A

left

33
Q

Asymmetric Encryption

A

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
Q

Advantages of networks

A
  • 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
Q

Real-time Operating system

A

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

36
Q

software

A

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

37
Q

Client side processing

A

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

38
Q

Disadvantages of the agile model

A
  • Not suitable for quick projects
39
Q

Current instruction register

A

stores the actual instruction that is being decoded

40
Q

if/else Pseudocode

A
if condition then
code
elseif condition then
code
else
code
endif
41
Q

dynamic

A

size of the structure can change at runtime

42
Q

Optical storage advantages

A

Cheap
light weight and portable
Resilient

43
Q

Trace Tables

A

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

44
Q

structured

A

the data is organised in a logical way

45
Q

purpose of operating systems: managing the memory

A

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

46
Q

constructor of a superclass

A

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

47
Q

instruction set

A

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

48
Q

code optimisation

A

(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
Q

Multiple cores

A

Multiple CPUs working on a single computer

50
Q

Pre-emptive

A

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

51
Q

Inheritance OO pseudocode

A
class Dog inherits Pet
code
endclass
52
Q

Address Bus

A

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
Q

XML (eXstensible Markup Language)

A

A markup language that uses tags to denote data

54
Q

Methods of sending data

A

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
Q

CISC

A

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

56
Q

Clock signal

A

used to synchronise operations

57
Q

font size CSS property

A

font-size

58
Q

Uses of real-time operating systems

A

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

59
Q

purpose of operating systems: providing networking

A

communication through protocols and other machines and devices

60
Q

Durability

A

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

61
Q

wildcard

A

*, selects all the elements

62
Q

Tuples

A

are lists that cannot be edited, they are immutable

63
Q

Hash tables

A

an array which is coupled together with a hash function.

64
Q

stack data structure

A

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
Q

second normal form

A
  1. Check the data is already in 1NF
  2. Remove any partial dependencies
  3. ‘fix’ any many to many relationships you discover
66
Q

Open Systems Interconnection 7 layer model

A

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

67
Q

Query SQL

A

SELECT *
FROM tblName
WHERE conditions

68
Q

stepwise approach

A

breaking down a problem into smaller sections

69
Q

Server side processing

A

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

70
Q

sequential files

A

where the order of data is maintained

71
Q

how to do CSS in HTML

A

<h1></h1>

72
Q

Data Protection Act parts

A

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
Q

How is a stack used in a ISR

A

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
Q

A

OR (+)

75
Q

protecting agaisnt hacking:

A
  • Packet snifferes

- User access logs

76
Q

Attribute

A

variables contained within and associated to an object

77
Q

BIOS

A

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

78
Q

polling

A

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
Q

how does arithmetic (signed) right shift work?

A

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

80
Q

normalising a positive binary number

A

back fill with 0s

81
Q

Input device examples

A
Key board
Card readers 
Microphones
Cameras
Barcode scanners
OMR/OCR
Mice
Sensors
Magnetic stripe reader
touch pads
82
Q

Object Orientated language

A

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

83
Q

sparse graph

A

A graph which has few edges in relation to vertices

84
Q

Solid-State Storage

A

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

85
Q

graph

A

a set of edges/arcs connecting vertices/nodes

86
Q

linking a css/javaScript file

A

<a> link text </a>

87
Q

Link Layer

A

(4) Passes data to the physical network

88
Q

Hashing Databases

A

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

89
Q

De Morgan’s Law

A

¬ (A∨B) = (¬ A) ∧(¬ B)

NOT (A OR B) is the same as (NOT A) AND (NOT B)

90
Q

Foot Mouse

A

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

91
Q

Secondary key

A

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

92
Q

Bitwise manipulation

A

bitwise shifts and masks

93
Q

Bytecode

A

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

94
Q

multi-dimensional arrays

A

an array containing one or more arrays.

95
Q

Advantages of Using encapsulation

A
  • reduces chance of error
  • consistent changes
  • prevents accidental changes
96
Q

word

A

equal units of memory. each with separate memory addresses.

97
Q

fragmented disk

A

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
Q

procedure

A

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

99
Q

Algorithm for insertion into a binary tree:

A
  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
Q

different traversal methods

A

preorder
inorder
postorder

101
Q

Coacial Copper Cables

A

older, slower and cheaper

102
Q

node at the top of the tree

A

root node

103
Q

Chip Multi Processor (CMP)

A

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

104
Q

border width CSS property

A

border-width

105
Q

factors to consider when choosing applications (9)

A
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
Q

TCP/IP stack

A

Application Layer
Transport Layer
Internet layer
Link Layer

107
Q

Execute

A

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

108
Q

Artificial intelligence

A

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

109
Q

What is a more complex data type called?

A

composite types

110
Q

Star topology disadvantages

A

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

111
Q

Uses of assymetric encryption

A

used for transfering data e.g. online shopping

112
Q

basic Boolean operators

A

AND
OR
NOT

113
Q

all attributes are dependent on..

A

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

114
Q

height CSS property

A

height

115
Q

Peer-to-Peer Model:

A

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

116
Q

distributed computing

A

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

117
Q

SMTP

A

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

118
Q

Software interrupts

A

illegal instruction encountered
Arithmetic overflow
new log-on request

119
Q

Uses of CISC

A

what most desktops use, Intel or AMD

120
Q

Benefits of circuit switching

A
  • highly reliable

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

121
Q

Drawbacks of circuit switching

A
  • 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
Q

Puff/Suck Switch

A

blow/suck to send signal.

123
Q

Buffer almost empty

A

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

124
Q

NIC

A

receive and send electrical signals in a network.

125
Q

partial key dependency

A

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

126
Q

Data Integrity

A

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

127
Q

internal storage examples

A

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

128
Q

Use of distributed operating systems

A

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

129
Q

Output device examples

A
speakers
plotters
printers
monitors
actuators
projectors
LEDs
130
Q

Static

A

the size of the structure cannot change at run time

131
Q

indexed addressing

A

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

132
Q

What does a bitwise left shift do?

A

multiplies the number by 2.

133
Q

Binary -> denary negative exponent

A
  • exponent
134
Q

create an instance of a class OO

A

objectName = new className(parameters)

135
Q

Breadth first algorithm

A
  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
Q

Absorbtion Law OR

A
A∧(A∨B)=A
X AND (X OR Y) is the same as X
137
Q

procedural languages examples

A

Pascal, C, Basic and Python

138
Q

What is ASCII

A
  • A character set
  • Maps values to characters
  • Uses 7-bits/ 8-bits per character
139
Q

types of interrupts

A
  • hardware
  • software
  • Input/output
140
Q

A∧ ¬A =

A

0

141
Q

Contemporary processor architectures

A

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
Q

Sign magnitude most significant bit

A

represents + or -
+ = negative
- = positive

143
Q

Hashing

A

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
Q

Memory read signal

A

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

145
Q

Bus request signal

A

indicates that the CPU has granted access to the data bus

146
Q

polymorphism

A

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

147
Q

Inserting an item in a hash table:

A
  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
Q

opcode

A

the actual instruction

149
Q

0.1

A

positive

150
Q

Open Source Software

A

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

151
Q

\

A

integer division

152
Q

Drawbacks of closed source software

A
  • costs money, can be expensive

- small range of versions of software

153
Q

purpose of operating systems: managing security

A

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

154
Q

Bottleneck address bus

A

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

155
Q

Input devices for limited mobility

A
  • Foot mouse/pedal
  • Camera/eye tracker
  • Microphone
  • Puff/suck switch
156
Q

Lists

A

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

157
Q

anchor tag

A

<a></a>

158
Q

Lossy Compression

A

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
Q

serial file

A

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
Q

commutation LAW OR

A

A∨B = B∨A

The order in which two variables are OR’ed makes no difference

161
Q

purpose of operating systems: managing the processor

A

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

162
Q

Half adder use

A

adds two bits

163
Q

commutation LAW AND

A

A∧B = B∧A

The order in which two variables are AND’ed makes no difference

164
Q

end instruction

A

HLT

165
Q

Binary -> denary positive exponent

A

+ exponent ->

166
Q

Packet Switching

A

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
Q

Address bus average width

A

32 bits

168
Q

normalising a negative binary number

A

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

169
Q

Possible uses of graphs:

A
  1. Navigation Systems
  2. Data Transmission
  3. Web page links
  4. Social media trends
170
Q

Disadvantages of extreme programming

A
  • Not suitable for programmers separated geographically

- Client must be able to commit to having full time contact with the programmers

171
Q

programming paradigm

A

a way to classify programming languages based on their features.

172
Q

how to solve hash table collisions

A
  • store the key in in the next available space
    OR
  • combine with a linked list
173
Q

Data redundancy

A

The unnecessary duplication of data in a database

174
Q

<p></p>

A

paragraph text

175
Q

capacity of solid state

A

around 500 MB

176
Q

Uses of virtual machines

A
  • used on networks to avoid redundant processors
  • translating code (Java)
  • running different operating systems
177
Q

Mesh Topology

A

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

178
Q

Memory Data register (MDR)

A

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

179
Q

normalising:

moving the point to the left

A

+ exponent

180
Q

relationship between high-level and assembly code

A

one to many

181
Q

uses of a GPU

A
Will be present on a graphics card in a computer
used in
- Machine learning
- Oil exploration
- Image processing
- Financial transactions
182
Q

virtual storage disadvantages

A

Expensive if you want to store large amounts of data

Access times can be slow if there is poor internet connection

183
Q

Cop Right Design and Patents Act

A

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
Q

post order dot

A

right

185
Q

<ol></ol>

A

ordered list

186
Q

Paired Programming

A

one programmer types and another checks at the same time.

187
Q

border style CSS property

A

border-style

188
Q

Transmission media

A

the wires that connect a network

189
Q

system software

A

operates, controls and maintain the computer and its components.

190
Q

Bitwise ANDing …

A

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
Q

main factors effecting CPU performance

A

clock speed
number of cores
amount and type of cache

192
Q

ACID

A

Atomicity
Consistency
Isolation
Durability

193
Q

What do the nodes on a binary tree contain

A

left pointer, data, right pointer

194
Q

CDPA year

A

1988

195
Q

Disadvantages of the spiral model

A
  • Acknowledge user input
  • Create prototypes to communicate to the user ideas better
  • Better for small projects
  • Simple
196
Q

general purpose application software

A

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

197
Q

FIFO

A

first in first out

198
Q

digraphs

A

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

199
Q

Internet

A

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

200
Q

Embedded Operating Systems

A

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

201
Q

Switches

A

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
Q

Output device

A

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
Q

drawbacks of assymmetric

A
  • not as fast
204
Q

MOD

A

gives the remainder of a division

205
Q

three main class sections:

A

class name
attributes
methods

206
Q

Record Locking

A

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

207
Q

Multi-tasking operating system

A

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
Q

API

A

Application Programming Interface governs how two applications should interact

209
Q

Adding data from linked lists:

A
  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
Q

5 most common primitive data types

A

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

211
Q

Removing data from linked lists:

A
  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
Q

mutable

A

structure and data can be changed at runtime

213
Q

what connects different networks?

A

routers and gateways

214
Q

Disadvantages of client side processing

A
  • 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
Q

Utility software

A

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

216
Q

CSS identifier

A

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

217
Q

for loop pseudocode

A

for i=0 to 7
print(“Hello”)
next i

218
Q

deadlock

A

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

219
Q
A

The text that will appear in the tab heading

220
Q

linker (static linking)

A

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
Q

Extreme Programming

A
  • 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
Q

exponent

A

positive of the binary point is fixed on the number line

223
Q

What loads the OS into RAM

A

the bootloader

224
Q

Buffer

A

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

225
Q

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

A

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
Q

token

A

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

227
Q

arcs on a tree

A

branches

228
Q

Relational Database

A

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
Q

uses of functions and procedures

A

breaking a problem into manageable sections

preventing duplicating sections of code when it is needed more than once in a program

230
Q

Operating system (System software)

A

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
Q

normalising a number

A

means that there is only one way to represent the number

232
Q

virtual storage advantages

A

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
Q

Operating System Roles

A
  • 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
Q

bootloader program

A

loads the operating system kernel into memory.

Stored in ROM

235
Q

Where is the waterfall life cycle model used?

A

Used in manufacturing industry

236
Q

Over-riding

A

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
Q

Characteristics of Procedural

A

instructions, sequences, selections, interaction, procedures and functions

238
Q

clock

A

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
Q

Cache memory

A

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

240
Q

interrupts

A

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

241
Q

Unicode

A

character set which displays over a million characters

242
Q

scheduler

A

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

243
Q

What are character sets needed for?

A

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
Q

Hardware

A

the physical component oft he computer system.

245
Q

Microphone

A

Make sound to send signal

246
Q

advantages of using an external css file

A

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

247
Q

program branch reason

A

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

248
Q

primitive data type

A

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

249
Q

array

A

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

250
Q

Data mining

A

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

251
Q

different types of operating system

A
Distributed
Embedded
Multi-tasking
Multi-User
Real-time
252
Q

Hash function

A

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
Q

interpreter

A

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
Q

CPU vs GPU

A

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

255
Q

Cloud Computing

A

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

256
Q

What does the DMBS provide

A
Security
backups
index updating
enforcement of referential integrity
facilities to update and query the database
257
Q

client side processing

A

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

258
Q

Association LAW (OR)

A
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
Q

Solid-State examples

A

USB pens and SD cards

260
Q

advantages of peer-to-peer

A
  • cheap to set up and maintain

- easy sharing

261
Q

Algorithm for deletion into a stack:

A
  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
Q

conjunction

A

AND

263
Q

Atomicity

A

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
Q

integer

A

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

265
Q

how to normalise a number:

A
  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
Q

Fibre Optic Cables

A

newer, faster and high-capacity

267
Q

Code generation

A

(stages of compilation stage 3)

the syntax tree is converted into object code

268
Q

Advantages of a client-server network

A
  • 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
Q

Algorithm for insertion into a queue:

A
  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
Q

Hardware interrupt

A
  • 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
Q

why is manageable code important

A

easy to read, debug and easy to maintain

272
Q

logic gates in a half adder

A

XOR (to the sum)

AND (to the carry)

273
Q

application layer

A

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

274
Q

Object Orientated languages examples

A

C++ and Java

275
Q

The Computer Misuse Act

A

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
Q

virtual memory

A

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
Q

first normal form

A
  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
Q

Solid-state storage disadvantages

A

Expensive

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

279
Q

Operating System

A

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

280
Q

LIFO

A

last in first out

281
Q

what happens when a search engine indexes a page

A

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
Q

three types of secondary storage

A

magnetic, optical, solid-state

283
Q

Method of capturing data (Automated)

A

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

284
Q

4 types of system software

A

OS, utility, libraries, translators

285
Q

JPEG

A

joint photographic experts group, losy compressed form of graphics storage

286
Q

X∨0 =

A

X

287
Q

SQL

A

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
Q

Referential Integrity

A

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
Q

Pre-emtive Algorithms

A

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

290
Q

Dictionary Coding

A

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
Q

more bits in the mantissa…

A

improves the accuracy but reduces the range

292
Q

RISC

A

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

293
Q

magnetic storage positives

A

cheap large capacity

294
Q

OR

A

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

295
Q

Advantages of the waterfall model

A
  • Everyone on the project is very clear on their responsibilities at each stage.
  • Simplicity
  • Easy to see if programming is running to schedule
296
Q

limitations of half adders

A
  • can only add one bit numbers

- only two inputs, the carry from a previous addition can’t be incorperated

297
Q

Atomic

A

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

298
Q

Malicous Software

A

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

299
Q

XML

A

extensible markup language, text based means of describing data.

300
Q

types of application software (12)

A
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
Q

real (floating point)

A

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

302
Q

CISC advantage

A

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

303
Q

Data integrity is the state of data being

A

as intended and accurate

304
Q

disadvantages of peer-to-peer

A
  • no central backing up
  • slower performance
  • bad security
305
Q

CSS identifiers vs classes

A

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

306
Q

SIMD

A

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

307
Q

GPU uses

A

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

308
Q

Multi-User Operating System

A

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

309
Q

Drawbacks of packet switching

A
  • protocols are complex and expensive
  • packets may be lost
  • not neccessarily secure
310
Q

Variable

A

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
Q

Serialisation

A

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

312
Q

ASCII

A

American Standard Code for Information Interchange

313
Q

three categories of programming languages

A

procedural
Object Orientated
Assembly

314
Q

X∨¬X=

A

1

315
Q

Proxies

A

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

316
Q

disadvantage of server side processing

A
  • can be slow

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

317
Q

Hubs

A

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

318
Q

Association LAW (AND)

A
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
Q

difference between paging and segmentation

A

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
Q

Embedded operating systems

A

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

321
Q

Star Topology

A

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

322
Q

what does security keeping data safe from?

A
  • accidental or deliberate loss

- malicious access

323
Q

Bus Topology Disadvantages

A

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

324
Q

What does the width of the address bus determine

A

the maximum possible memory addresses of the system

325
Q

Lossless Compression

A

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
Q

drawbacks of open source software

A
  • can be less user friendly/less easy to use
  • less support available
  • people may exploit failures maliciously before they are fixed
327
Q

Shortest job first (SJF)

A

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

328
Q

advantages of client side processing

A
  • Allows for more interactivity by immediately responding to a users’ action
  • Removes potentially unnecessary processing from the server
329
Q

Ring topology

A

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

330
Q

tree

A

a simple connected graph with no cycles

331
Q

Primary key

A

A field that uniquely identifies each record

332
Q

Secondary Key

A

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

333
Q

Disadvantages of rapid application development

A
  • doesn’t scale well
334
Q

Searching an item in a hash table:

A
  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
Q

Input instruction

A

INP

336
Q

1.0

A

negative

337
Q

Data Bus

A

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

338
Q

GPU

A

Graphical processing unit.

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

339
Q

uses of linked lists

A
  1. Implementing undo functionality
  2. Dealing with browser cache
  3. Helping with operating system job queues
340
Q

store instruction

A

STA

341
Q

RIPA Grants rights to:

A
  • 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
Q

program branch result

A

the next instruction held in the PC is not carried out

343
Q

pipelining

A

overlapping stages in the fetch-execute cycle.

fetching the next instruction while the first instruction is being decoded

344
Q

example of input AND output device

A

touch screen or games controllers

345
Q

Embedded Operating Systems

A

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

346
Q

Harvard architecture

A
  • instructions and data are stored in separate memory units
  • instructions and data are each served by their own buses
  • allows for pipelining
347
Q

CMA year

A

1990

348
Q

Composite Key

A

A unique identifier made from different fields

349
Q

positives of databases?

A
  • provide security
  • provide automatic backup
  • enforce data integrity rules
  • control data redundancy
  • provide users with controlled access to data they need
350
Q

Superclass

A

the original class and its code

351
Q

pipelining advantages

A

improves efficiency

352
Q

combine rows from multiple rows

A

JOIN

353
Q

What does a bitwise right shift do?

A

divides the number by 2.

354
Q

Overflow

A

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
Q

negatives of multiple cores

A
complicated circuitry (more expensive) 
doesn't always improve performance
356
Q

by changing the position of the binary point you can…

A

increase the size of the number

increase the accuracy of the number

357
Q

MIMD

A

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

358
Q

Local Area Network (LAN):

A

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
Q

Benefits of Open source software

A
  • 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
Q

instantiation

A

the process of creating an object from a class template

361
Q

Uses of Multi-tasking operating systems

A

desktops and smart phones

362
Q

Entity Relationship Modelling

A

when the relationships between tables are shown in abstracted view.

363
Q

CISC disadvantages

A
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
Q

How does Java use virtual machine?

A

the virtual machine execute intermediate code (Java Byte code)

365
Q

Half adder outputs/inputs

A

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

366
Q

Algorithm for deletion/reading from a queue:

A
  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
Q

Writing an alert box

A

alert(“Hello World”);

368
Q

Search engine indexing

A

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

369
Q

<div></div>

A

divides the page into segments allowing for improved styling

370
Q

input device

A

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
Q

utility programs examples

A
  • Disk defragmenter
  • Automatic backup
  • Automatic updating
  • Virus checker
  • Compression software
372
Q

Input/output interrupt

A
  • Buffer almost empty

- Signals the completions of data transfer between devices

373
Q

X∨X=

A

X

374
Q

First come first serve (FCFS)

A

the processes are executed in the order they arrived

if all the processes take along time all the others must wait

375
Q

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

A

by putting instructions on a stack

376
Q

how to use a form tag

A
377
Q

changing the contents of an HTML element JavaScript

A

chosenElement = document.getElementById(“example”);

chosenElement.innerHTML = “Hello World”;

378
Q

writing directly to a document JavaScript

A

document.write(“Hello World”);

379
Q

Benefits of packet switching

A
  • efficient use of the network
  • can be rerouted to avoid problems in the network
  • data is transmitted immediately
380
Q

JavaScript Clientside

A

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
Q

Normalisation

A

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

382
Q

Firewalls

A

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
Q

Flip flop

A

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

384
Q

Server side processing

A

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

385
Q

Encryption

A

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

386
Q

Advantages of rapid application development

A
  • flexible to changes
  • quick
  • simple
  • can reduce risk
387
Q

Input/ Output interrupts

A

buffer nearly empty

signal the completion of data transfer to/from a device

388
Q

translator

A

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

389
Q

Disadvantages of Networks

A

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
Q

branch if zero instruction

A

BRZ

391
Q

RISC disadvantages

A

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

392
Q

advantages of server side processing

A
  • doesn’t require plugins or browser scripting technology
  • more secure
  • reduces loading time
393
Q

third normal form

A
  1. Check the data is already in 2NF

2. Check there are no non-key-dependencies

394
Q

Disk defragmentation

A

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

395
Q

Trojan

A

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

396
Q

Negation

A

NOT

397
Q

Layering

A

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

398
Q

4 types of application software

A

off the shelf, custom written, proprietary and open source

399
Q

record

A

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

400
Q

capacity of optical

A

700MB - 50GB

401
Q

branch if zero or positive instruction

A

BRP

402
Q

Memory Address register (MAR)

A

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

403
Q

Advantages of using byte code interpreters

A
  • Achieve platform independence

- Acts as an extra security layer between program and computer

404
Q

Bus topology advantages

A

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

405
Q

pipelining disadvantages

A

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

406
Q

create a new table SQL

A

CREATE TABLE tblName

407
Q

Why is paging not efficient

A

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

408
Q

What is a mask?

A

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

409
Q

Clock speed Unit

A

Hertz (usually gigahertz)

410
Q

Port

A

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
Q

Buses

A

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

412
Q

Flash

A

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

413
Q

Inserting items into a binary search tree:

A

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
Q

What does ASCII stand for

A

American Standard Code for Information Interchange

415
Q

Negatives of Symmetric encryption

A

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
Q

<ul></ul>

A

unordered list

417
Q

Non pre-emptive algorithms

A
  • First come first serve

- shortest job first

418
Q

Benefits of asymmetric

A
  • no movement of keys, more secure

- can be used for digital signatures

419
Q

data storage instruction

A

DAT

420
Q

binary search tree

A

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
Q

Optical storage disadvantages

A

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

422
Q

What does an OS provide?

A
  • User interface
  • Memory Management
  • Interrupt handling
  • Processor scheduling
423
Q

writing to a file

A

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

424
Q

Why Do RISC processors result in increased battery life

A
  • smaller instruction set
  • fewer transistors/ less complex circuitry
  • less power required
425
Q

Negatives of increasing clock speed

A

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

426
Q

Timer Interrupts

A

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
Q

AND

A

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

428
Q

Method

A

a subroutine associated with an object

429
Q

Wide Area Network (WAN:

A

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

430
Q

ROM

A

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
Q

examples of system software

A

Operating system, Utility Program, Library Program, Translators.

432
Q

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

A

each type of processor has its own unique instruction set

433
Q

Device drivers are…

A

hardware dependent and OS specific

434
Q

Database

A

Databases are structured, persistent collections of data.

435
Q

Uses of RISC

A

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

436
Q

boot up process of a computer

A
  • 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
Q

What is bitwise manipulation useful for?

A
  • Compression Algorithms
  • networks (protocols. routing packets)
  • multiplication and division
438
Q

Wireless Access Point

A

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

439
Q

X∧1=

A

1

440
Q

fixed point binary

A

positive of the binary point is fixed on the number line

441
Q

preorder traversal

A
  1. Visit the root
  2. Traverse the left sub-tree
  3. Traverse the right-sub-tree
442
Q

Parallel processing/concurrent processing

A

multiple processors working at the same time

443
Q

Agile Modelling

A
  • 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
Q

Advantages of the spiral model

A
  • good from projects with high levels of risk

- suitable for large scale problems

445
Q

benefits of symmetric

A
  • encrypted very quickly

- simple and easy

446
Q

Co-processor

A

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
Q

width CSS property

A

width

448
Q

advantage of normalisation

A

it stores the most accurate version of that number.

449
Q

Load instruction

A

LDA

450
Q

while loop pesudocode

A

while condition=
code
endwhile

451
Q

Virtual storage

A

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

452
Q

Von neumann architechture

A
  • 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
Q

Disjunction

A

OR

454
Q

Procedural programming languages

A

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

455
Q

automated decision making

A

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

456
Q

compression

A

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

457
Q

system bus

A

collective term for address, data and control bus

458
Q

RIPA year

A

2000

459
Q

Flat File

A

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

460
Q

Shortest remaining time (SRT)

A

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
Q

Bitwise shifts can be used …

A

to change numbers quickly

462
Q

digital signature

A

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
Q

Uses of Multi-user operating systems

A

schools and offices

464
Q

censorship

A

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

465
Q

Benefits of high level code (over assembly)

A
  • optimisers may make code more efficient
  • intuitive and easier to write
  • can be recompiled for different architechtures
  • less code is written (shorter programs)
466
Q

Internal css vs external css

A

internal is within the document external is linked to html code

467
Q

inorder traversal

A
  1. Traverse left sub-tree
  2. Visit the root
  3. Traverse the right sub-tree
468
Q

Syntax analysis

A

(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
Q

Condition between two values SQL

A

WHERE x BETWEEN a AND B

470
Q

The Regulation of Investigatory Powers Act

A

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

471
Q

flip flop logic gates

A

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

472
Q

Benefits of assembly code (over high level)

A
  • efficient as the code is more specifc
  • direct control of hardware
  • good if no compilers/interpreters installed
  • good if limited memory
473
Q

DIV

A

integer division (rounds down)

474
Q

Round robin (RR)

A

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
Q

Pre-emptive algorithms

A
  • Round Robin
  • Shortest Remaining Time
  • Multi-level feedback queue
476
Q

Multi-level feedback queue

A

uses multiple queues based of the priority of the process.

477
Q

Uses of Hashing

A
  • generating disk address

- storing and checking passwords

478
Q

postorder traversal

A
  1. Traverse the left sub-tree
  2. Traverse the right sub-tree
  3. Visit the root
479
Q

full image tag

A

<img></img>

480
Q

Requirements specification

A

A document listing all the functionality the system should have

481
Q

X∧¬X=

A

0

482
Q

external storage examples

A

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

483
Q

Meta tags, keywords, descriptions

A

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

484
Q
A

the tag to include JavaScript code

485
Q

Absorbtion Law AND

A
A∨(A∧B) = A
X OR (X AND Y) is the same as X
486
Q

iteration

A

do a set of statements again and again (looping)

487
Q

delete rows of a table

A

DELETE
FROM
WHERE

488
Q

Bottleneck data bus

A

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

489
Q

Encapsulation

A

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

490
Q

Where is RAD used?

A

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

491
Q

Multi-user operating system

A

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
Q

Subclass

A

the new class which inherited from the superclass

493
Q

condition controlled time

A

repeat a set number of statements until a condition is met

494
Q

mantissa

A

the actual number you want to store

495
Q

Application Programming Interface (API)

A

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

496
Q

Where is extreme programming used?

A

good for when the requirements change

497
Q

Algorithm for insertion into a stack

A
  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
Q

Accumulator

A

stores the result of calculations made by the ALU

499
Q

scheduler

A

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

500
Q

Control Unit

A

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
Q

<li>
</li>

A
The individual parts of the list
<ol>
<li>
</li><li>
</li><li>
</li>
</ol>
502
Q

example uses of flip flops

A
  • in registers

- static RAM

503
Q

distributed operating systems

A

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
Q

<h1></h1>

<h2></h2>

<h3></h3>

A

heading text

505
Q

Spiral Model

A
  • 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
Q

Antivirus utility software

A

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

507
Q

ROM acronym

A

read only memory

508
Q

segmentation

A

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

509
Q

CSV (Comma Separated Value)

A

A text file/format with values separated by

commas

510
Q

Backing Up

A

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
Q

order of main HTML tags

A
512
Q

RAM

A

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
Q

Memory write signal

A

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

514
Q

Purpose of Compression

A
  1. Reduce download times
  2. Reduce requirements on file storage
  3. Make best use of bandwidth
515
Q

PDF

A

portable document format, to display documents exactly as intened

516
Q

d page rank

A

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

517
Q

¬(¬A) =

A

A

518
Q

relationship between the DNS server and IP addresses

A

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
Q

Worm

A

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

520
Q

Disadvantages of the waterfall model

A
  • The absence of user feedback
  • not suitable for large projects
  • Requirements must be very well understood
521
Q

positives of multiple cores

A

may speed up processing

522
Q

Arithmetic Logic Unit

A

Carries out calculations and logic (Comparisons of binary)

523
Q

Control signals

A
  • Memory read
  • memory write
  • bus request
  • clock signal
524
Q

by default how are parameters passed?

A

by value

525
Q

Boolean

A

Any true/ false data types which often represent logical situations

526
Q

closed source software

A

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
Q

GIF

A

graphics interchange format, lossless compressed image file format

528
Q

Transport Layer

A

(2) Makes and breaks connections with routers

529
Q

Registers

A

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

530
Q

Deleting an item in a hash table:

A
  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
Q

persistent

A

the data remains for as long as its required

532
Q

Transaction Processing

A

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

533
Q

Order Queried data SQL

A

ORDER BY

534
Q

Where is the spiral model used?

A

Used in large scale projects

535
Q

MAN

A

metropolitan area network

536
Q

need for secondary storage

A

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

537
Q

reading from a file

A

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

538
Q

Camera/eye tracker

A

Move/blink to send signal

539
Q

Object

A

Instance of a class

540
Q

immutable

A

structure and data cannot be changed at runtime

541
Q

relational databases

A

multiple tables linked together

542
Q

data bus width

A

same as the computers word size

543
Q

indexing

A

used to quickly access and locate data in a table

544
Q

When is Bitwise ANDing useful?

A

useful for TCP/IP and routing

545
Q

nodes with no sub-nodes

A

leaf-nodes or terminal nodes

546
Q

Check if an attribute is similar to a given value SQL

A

LIKE

547
Q

Decode

A

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
Q

Loaders (dynamic linking)

A

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
Q

composite key

A

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

550
Q

Advantages to Peer-to-peer networking

A
  • Cheap
  • Enables users to share resources
  • not difficult to maintain
551
Q

assignment operator

A

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

552
Q

Interrupt register

A

generates and detects interrupts

553
Q

constructor method

A

signified by the key word new, initiated instantiation

554
Q

lexical analysis

A

(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
Q

Isolation

A

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
Q

assembly language

A

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

557
Q

more bits in the exponent…

A

improves the range but reduces accuracy

558
Q

constant

A

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
Q

RISC advantages

A

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
Q

collision (hash table)

A

when the same hash value is given by two different keys

561
Q

advantages of Client-Server

A
  • User IDs, passwords and access levels centrally controlled
  • Backup is centralised and usually automated
  • No access to other users’ files
562
Q

breadth first traversing

A

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
Q

negative of increasing cache size

A

expensive

564
Q

Multitasking operating system

A

can run multiple programs simultaneously

565
Q
A

defines a form that is used to collect user input

566
Q

function

A

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

567
Q

Full adder inputs/outputs

A

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

568
Q

string

A

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

569
Q

magnetic storage examples

A

magnetic tape, floppy disks hard disk drives

570
Q