Everything 1 Flashcards
(500 cards)
1
Q
SRAM =
A
static RAM
2
Q
Optical media is also known as
A
offline storage
3
Q
NIC =
A
Network interface card
4
Q
What are the signs of a DoS or DDoS?
A
V slow internet on network / can’t access some websites / large amounts of spam
5
Q
SSDs are also known as
A
flash memory or flash storage
6
Q
Abnormal data
A
Any data that is not accepted
7
Q
What memory stores data the computer accesses directly
A
primary memory
8
Q
Any form of data needs to be converted to ________ format
A
binary
9
Q
CDs and DVDs use what colour laser?
A
red
10
Q
Secondary storage includes -
A
HDD and SSD
11
Q
Floating gates and control gates are found in
A
transistor junctions for SSDs
12
Q
What are problems with packet loss
A
Lost packets accumulate and network slows
13
Q
What are the 8 bit binary placeholders?
A
128 / 64 / 32 / 16 / 8 / 4 / 2 / 1
14
Q
What is stealing data by tapping into wired or wireless communication links?
A
Data interception
15
Q
What is latency in HDDs?
A
Time it takes for block of data to rotate to the head and be read
16
Q
In a flowchart, what is an input/output?
A
Input or output of something into our out of the flowchart
17
Q
FETCH - What happens after MAR receives instruction via address bus?
A
Instruction copied to MDR
18
Q
In the PDLC - what is testing?
A
Testing a product to make sure it works as intended
19
Q
What is data interception?
A
Stealing data by tapping into wired or wireless communcation links
20
Q
DVD-RAM is different because
A
It has many concentric tracks and acts more like a hard drive
21
Q
Most common use of DVDs or Blu-rays is
A
games/movies
22
Q
HDD =
A
hard disc drive
23
Q
Example of parallel data transmission
A
Internal circuits in a computer
24
Q
How to convert hex to denary?
A
Convert to hex to binary -> binary to denary
25
In the PDLC - what is coding?
Third step, programming
26
What's an actuator?
a device that produces motion (e.g. controls wheels, motors, magnets)
27
What are advantages of USBs?
simple interface - cable only works one way so less chance of errors // relatively high speed data transfer // universal - lots of devices use USB // can be used for power // automatically detected by computer to transfer
28
What do we call input devices that take readings and send them to a computer or microprocessor?
sensors
29
What's the order of data units from smallest to largest?
bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte
30
Packet trailer contains
ID of end of packet and error checking (CRC)
31
video, images, sounds, text, numbers, facts are all forms of
data
32
Whare are structure diagrams?
Structure diagrams are used to represent sub-systems that make up a system. Each sub-system is also split into smaller sub-systems.
33
One direction only describes what?
Simplex data transmission
34
The smallest piece of computer memory is a
bit
35
Which type of RAM has a higher memory capacity?
DRAM
36
What is a USB port?
A socket in a device/computer that allows you to plug in a cable
37
Non-volatile, not accessible by the CPU - which storage?
secondary
38
What are flowcharts?
Flowcharts indicates the inputs needed (requirements) and the processes to be followed (logic) that lead to the output (final outcome)
39
Which type of RAM is less expensive?
DRAM
40
A bit is....
the smallest piece of computer memory
41
How can you prevent DoS or DDoS?
Use up to date malware blockers / use firewalls to restrict traffic / use filters to block spam
42
Disadvantages of packets/packet switching
Packets can get lost, problems with real time streaming, delay when reassembling at end
43
What does the MAR do? (Memory address register)
stores the address of the memory location currently being read from/written to
44
In a flowchart, what is a terminator?
Start and stop of process
45
Denary counts in multiples of ____
10
46
Secondary storage can be ______ or _______
secondary storage can be internal or external
47
Drawbacks of SSDs
longevity, SSD endurance not as good as HDDs // can't overwrite data, have to delete first then write new
48
How is data transmitted by USB
Uses serial data transmission / sending data to and from peripherals or devices.
49
What kinds of USB are there?
USB ports, USB cables, USB connections, USB devices
50
In the PDLC - what is design?
Second step refers to thinking about the technical and visual aspects of your product.
51
In the PDLC - what is analysis?
First step, the process of understanding what exactly you need as inputs to build your product and if you have enough resources.
52
Hexadecimal is base ___
16
53
How many bytes in a kilobyte?
1024 bytes in a kilobyte
54
stores data that computers need to access when powering up (BIOS or bootstrap)
ROM
55
How to reduce fragmentation problems in HDDs?
Defragment the hard drive
56
Convert 8 to binary
1000
57
NIC contains a ______ address
MAC
58
8 bits is a
byte
59
Convert 15 to binary
1111
60
What does the CU do? (control unit)
manages the execution of each instruction
61
Floating gates and control gate transistors use what technology?
CMOS (complimentary metal oxide semiconductor) NAND technology
62
humans experience _________ data
analogue
63
Program code is usually written in ____
IDE (integrated development environment)
64
DoS or DDoS facts
Usually an internet server, usually temporary, very damaging and large breach of security, can be individual or group target
65
Normal data
Data within an accepted range
66
What are the 3 factors for data transmission to happen?
Direction of transmission, method of transmission and how synchronised
67
Another name for RAM is
IAS Immediate Access Store
68
Switch on = ___
1
69
In optical media laser wavelength determines
storage size - smaller wavelength = more storage
70
What's the difference between alpha and beta testing?
Alpha is testing it by yourself, Beta is testing on a target audience
71
What's the difference between a DoS and DDoS?
DDoS comes from many different computers all around the world
72
Example of serial data transmission
computer to printer via USB
73
All apps, operating systems, files are stored on...
secondary storage
74
Convert A00 to binary
1010 0000 0000
75
USB
Universal Serial Bus
76
Convert 43 to binary
101011
77
Convert 12 to binary
1100
78
What's synchronous data transmission?
Data is sent in a continous stream including timing signals made by an internal clock. Faster than asynchronous but the timing must be accurate. Used in network communication
79
CPU means
Central processing unit
80
Examples of optical media are
CDs, DVDs, Blu-rays discs
81
Convert 50 (hex) to binary
0101 0000
82
Flash memory includes
SSDs, memory sticks and flash drives
83
Boundary data
Values in upper and lower bounds - pair that's accepted, pair that's rejected
84
Optical media discs have either _____ or _____ tracks
single or concentric spiral tracks
85
Convert 62 to binary
111110
86
Describe the data bus
Carries / transports data / example of data that is currently being processed OR that will be OR that has been processed // Data can travel in both directions (bidirectional)
87
Which type of RAM uses less power?
DRAM
88
Denary is used by _____
humans
89
Why are USB cables limited to 5m usually?
More chance of errors in data transmission over long distances
90
What are the 12 bit binary placeholders?
2048 / 1024 / 512 / 256 / 128 / 64 / 32 / 16 / 8 / 4 / 2 / 1
91
Data is stored by moving electrons with NAND and NOR chips
SSDs / flash drives
92
What's asynchronous data transmission?
Groups of bits are sent with control bits. A pattern is agreed before sending and data has 'start' and 'end' bits. Stops data getting mixed during transmission
93
Parallel data transmission is...
several bits of data (usually a byte) sent down several wires or channels at the same time. Each wire transmits one bit.
94
2 types of MAC addresses are
Universally Administered Address (UAA) and Locally Administrered Address (LAA)
95
Optical media is used...
for backups, transfer files/media
96
What are examples of automated systems in real life?
industry, transport, agriculture
97
Automated systems are made up of
software and hardware (sensors, microprocessors/cpu, actuators)
98
Which type of RAM is main memory constructed of?
DRAM
99
What happens when you plug a USB into a computer?
Automatically detected - if it's the first time, a driver is downloaded, otherwise it works without needing to download each time
100
What benefit does dual layer offer blu-ray and DVDs?
more storage
101
What is a microprocessor?
Same role as CPU but smaller scale // usually for a specific task // AKA embedded system // example are traffic lights, digital alarm clocks
102
What are types of red laser optical media?
CD-RW/DVD-RW (write many), CD-R/DVD-R (write once)
103
What do microprocessors do in automated systems?
process data and perform programmed actions
104
Which type of RAM has a faster data access time?
SRAM
105
SSDs have two transistor junctions called
floating gates and control gates
106
Bit sent one after another, over a single wire or channel, one bit at a time describes what?
serial data transmission
107
Which type of RAM needs to be constantly refreshed?
DRAM
108
In programming, what is the name for the process of hiding complex details and showing only what is necessary?
abstraction
109
Serial advantages and disadvantages
Works well over long distance, data arrives synchronised. BUT slow.
110
Used to store data, files, part of an application or part of the operating system in use
RAM
111
What is the fetch decode execute cycle?
Everytime a computer performs a task or runs a program it runs the FDE cycle // Fetches the instruction into the CPU // CPU decodes the instruction // Instruction is executed by CPU
112
Binary is made up of ___ and ____ (numbers)
1 and 0
113
Both directions at the same time describes what?
Full-duplex data transmission
114
What do computers do to data?
process it
115
NIC is needed to
allow a device to connect to a network
116
SSD are solid state because
they have no moving parts
117
Data is stored in binary as millions of transistors on...
SSDs
118
What's a USB connection?
Anything that uses a USB cable plugged into a port
119
In programming, What is the name of the process of splitting a problem into smaller, manageable chunks?
decomposition
120
What are the steps in the PDLC?
Analysis / Design / Coding / Testing
121
What's a USB cable?
Type of cable that transmits data OR provides power
122
Binary digit is abbreviated to...
bit
123
What makes wireless data interception harder to do?
If data is encrypted using Wireless Equivalency Privacy (WEP)
124
Computers are made up of billions of tiny _______
switches
125
Why keep data safe?
It has either personal or business value
126
NICs can be ______ or _______
NICs can be wired or wireless
127
Packets are usually around ______ in size
64kb
128
What is full-duplex?
Both directions at the same time, example is broadband internet or online gaming
129
non-volatile =
contents not lost when power turned off
130
What are the 3 parts that make up analysis?
decomposition, analysis, requirements identification
131
Parallel data transmission advantages and disadvantages
works well over short distances. Fast. BUT over long distances data can become skewed and arrive out of order.
132
How is binary data stored on optical media?
in pits and lands, representing 1s and 0s
133
Coding phase of PDLC is also referred to as
implementation phase, because implements design from previous stage
134
What is the name used for the specific needs of a problem that must be identified as part of the problem analysis?
requirements
135
What is the PDLC?
Steps that are followed when developing a program (e.g. smartphone app or website)
136
Give a disadvantage of RAM
It's volatile
137
permanent memory - contents cannot change or be written to by user/computer/program
ROM
138
Convert 0110 to denary
6
139
Primary memory or primary storage includes
RAM and ROM
140
In optical media data is divided into
sectors
141
RAM = _______ ________ ________
random access memory
142
Data is stored on HDDs in ______ and ______
Data is stored on HDDs in sectors and tracks
143
What storage is not accesible by the CPU?
Secondary
144
CMOS (complimentary metal oxide semiconductor) NAND technology is used by what storage?
SSD or Flash drives
145
Iterative testing is useful because...
makes sure each section of code works as intended
146
What's a CPU?
Central processing unit // performs thousands of tasks and complex instructions // example smartphones or laptops
147
contents lost when power turned off
volatile
148
Packets are used to....
Send data from one device to another over the internet
149
Advantages of IDEs
Adds colour coding and indents to help organise code // helps identify errors using debugger // supports many programming languages
150
Software and hardware (sensors, microprocessors/cpu, actuators) are used in
automated systems
151
Describe the address bus
Carries / transports an address / location of the next item to be fetched // Data travels one way (unidirectional)
152
Describe the control bus
Carries / transports signals and controls / directs the actions of the CPU / processor // Can be either Unidirectional or Bidirectional
153
ROM = _______ ________ ________
read only memory
154
Examples of IDEs
Apache Netbeans, BlueJ and Microsoft Visual Studio Code
155
Wireless data interception is also called
wardriving/ access point mapping
156
Which type of RAM doesn't need to be constantly refreshed?
SRAM
157
What happens in the fetch step of FDE cycle?
PC contains address of memory location of next instruction // address is copied from PC to MAR via address bus // instruction at address contained in MAR temporarily copied to MDR using data bus // instruction of MDR copied into CIR // PC incrememts by 1, points to next instruction // instruction gets decoded then executed by signals via control bus to other parts of the computer
158
Packets are sent along different ________
routes
159
Facts about pseudocode
Resembles code but can't be understood by a computer // written for humans // easier for programmers to write and share since close to real code
160
Sensors are
input devices that take readings and send them to a computer or microprocessor
161
Binary is used by _______
computers
162
Increasing _____ usually makes your computer run more quickly
RAM
163
What are disadvantages of USBs?
Cables are limited to 5m usually // not as fast as other cables e.g. network cables
164
Blu-rays advantages
hold more than DVDs or CDs, faster rate of data transfer, automatically comes with encryption to prevent piracy
165
HDD uses what kind of storage
magnetic
166
Benefits of SSDs
more reliable as no moving parts // lighter // lower power // cooler // thinner // faster than HDDs // No disc to spin or 'get up to speed'
167
What's a USB device?
Anything that plugs into a USB port
168
Which memory is volatile?
RAM
169
In a flowchart, what is the flow line?
Arrow representing control passing between the connected shapes
170
What is a wordlist?
A very large text file containing common words for passwords
171
Two types of RAM are
DRAM and SRAM
172
Data can be...
corrupted, deleted, or intercepted - maliciously or accidentally
173
Both directions NOT at the same time describes what?
Half-duplex data transmission
174
What does secondary storage hold?
All apps, operating systems, files
175
Data transmission can either be over
long distance or short distance
176
Examples of personal information/data?
credit card number, bank account, date of birth, passport number, passwords
177
What is hopping?
Adding a hop number to each packet which reduces by 1 at each router. If number reaches 0, the packet gets deleted
178
A single 1 or 0 on a computer is called a
bit
179
Packet headers contain
sender IP address, receiver IP address, sequence number (for reassembly), size in bytes
180
Optical media tracks...
spiral from the centre to the edge of the disc
181
Convert A0 to binary
1010000
182
Magnetic storage includes
HDD
183
Data is stored on SSDs as
binary in millions of transistors
184
Convert 11111 to denary
31
185
Which memory is non-volatile?
ROM
186
How many bits in a MAC address and how are they grouped?
48 bits, six groups of 2 hex digits
187
____ is base 10
denary
188
Blu-ray lasers...
are blue and narrower than CDs or DVDs
189
What is data transmission?
Signals being sent from one device to another
190
_________ is base 16
hexadecimal
191
Removable HDDs are external and connect via
USB cable
192
HDD is magnetic storage because...
Disc heads are electromagnets and a magnetic field determines the binary value
193
DVDs and blu-rays can have what layer types?
single or dual
194
In a flowchart, what is a decision?
A decision (yes/no, true/false) that results in two lines representing different outcomes
195
What does iterative mean?
Any action that's carried out in a loop until it produces correct outcome
196
Switch off = ___
0
197
What does abstraction mean?
the process of hiding complex details and showing only what is necessary
198
Advantages of packets/packet switching
Easier to control than a stream of data, packets can go different routes in case route is busy/broken and allows high transmission of data
199
0 = switch ____
off
200
Convert AA to binary
10101010
201
Wired data interception uses a
packet sniffer
202
Which type of RAM is used by the CPU memory cache?
SRAM
203
DDoS
Distributed Denial of Service
204
What does the PC do? (program counter)
stores the address where the next instruction to be read can be found
205
Give an advantage of RAM over other types of memory
RAM is much faster to write to or read from than other types of memory
206
What do packet sniffers do?
Look at packets going over a network
207
What does the CIR do?
stores the current instructions being decoded and executed
208
Packet payload contains
The actual data (around 64kb)
209
How does packet switching work?
Each packet broken down at sender, sent independently, route decided by routers, receiver reassembles
210
serial data transmission can be ....
simplex, half-duplex or full-duplex
211
How to convert binary to hex
Start right and move left, convert each group of 4 bits. If less than 4 bits, fill in with 0s from left. Take each group of 4 and convert to hex
212
In hexadecimal A to F represent...
A = 10, B = 11, C = 12, D = 13, E = 14, F = 15
213
Binary is base __
2
214
How do you convert binary to denary?
Each time a 1 appears in a binary column, add the heading (value) to the total
215
Example of a 4 digit Hex number
A23F or 12FF or 79BB etc
216
What are some problems with HDDs and data?
Data stored gets fragmented which reduces performance // latency
217
A byte is ____ bits
8
218
Which type of RAM uses flip flops to hold each bit of memory?
SRAM
219
_____ is the basic building block of all computers
binary
220
What does the MDR do? (Memory data register)
stores data which has just been read from memory/data and is about to be written to memory
221
Why is test data important?
Make sure the product works as intended
222
Convert 1C to binary
0001 1100
223
Data is read from optical media by
The disc spinning and the disc head uses laser light
224
What is a cyber attack that is..usually an internet server, usually temporary, very damaging and large breach of security, can be individual or group target
DoS or DDoS
225
Data is sent from one device to another using ___________
packets
226
Which type of RAM consists of transistors and capacitors?
DRAM
227
How many kilobytes in a megabyte
1024 kilobytes in a megabyte
228
analogue data is experienced by
humans
229
DRAM =
dynamic RAM
230
Primary memory contains ____ _____ and _______________
ram, rom and cache memory
231
When you run a program data is retrieved from _____ ______ and placed temporarily into ____
When you run a program data is retrieved from secondary storage and placed temporarily into RAM
232
How to convert denary to hex?
Convert denary to binary -> binary to hex
233
Requirements dictate the ______ ______ to a program.
essential inputs
234
SSD and HDD are examples of...
secondary storage
235
Convert 6 to binary
110
236
examples of data are...
video, images, sounds, text, numbers, facts
237
____ is base 2
binary
238
What needs to be converted into binary before it can be processed by a computer?
data
239
When instructions are executed by CPU, what component performs maths and logic calculations?
Arithmetic Logic Unit (ALU)
240
In a flowchart, what is the process shape?
Represents something being performed or done
241
FETCH - What happens after the PC gets first instruction?
Address copied from PC to MAR
242
SSD stores data by
moving electrons with NAND and NOR chips
243
How does a DoS or DDoS work?
Floods a network with spam traffic and web servers can only handle so many requests, so they become overloaded and can't answer legitimate requests
244
DoS
Denial of Service
245
Convert 1001 1011 to hex
9B
246
How do cyclic redundancy checks work?
BEFORE SENDING - sender adds together 1 bits in payload and states value as hex in trailer / WHEN RECEIVED - receiver counts 1 bits, if they match accept it, if not request resent
247
Why does smaller wavelength = more storage in optical media?
smaller pit/land size so more binary data can be stored
248
What category of storage includes RAM and ROM
Primary
249
What are the 4 basic sub-systems that make up a computer system?
input / process / output / storage
250
Input / process / output / storage are...
the basic sub-systems that make up a computer system
251
What is the purpose of a DoS or DDoS?
Attempt at preventing users from accessing part of a network
252
What's the ALU's special register for storing interim calculations called?
Accumulator (ACC)
253
Convert 23 to binary
10111
254
Convert 101010 to denary
42
255
1 bit is a single
1 or 0
256
Serial data transmission is...
when data sent one bit at a time over a single wire or channel. bits are sent one after another
257
What is half-duplex?
both directions but NOT at the same time, example is walkie-talkie
258
Convert 1011101 to denary
93
259
Memory that's directly accessible by the CPU, contains RAM, ROM and cache memory
primary memory
260
contents not lost when power turned off
non-volatile
261
What's von Neumann architecture?
CPU access memory directly // memory stores programs and data // programs are series of instructions carried out in order
262
volatile =
contents lost when power turned off
263
Convert 1100 1010 to hex
CA
264
Example of short distance data transmission
computer to printer
265
What is a brute force attack?
A hacker tries to crack a password using all combinations of characters
266
Extreme data
Data at upper and lower bounds (accepted)
267
How is a MAC address divided?
NN-NN-NN-DD-DD-DD (Manufacturer-Device serial)
268
Parallel data transmission can be...
simplex, half-duplex or full-duplex
269
The design process involves which representations?
structure diagrams, flowcharts, pseudocode
270
Data is read and written to optical media by
laser light
271
MAC address =
Media Access Control address
272
What does decomposition mean?
the process of splitting a problem into smaller, manageable chunks
273
1 = switch ____
on
274
SSD =
solid state drive
275
Example of long distance data transmission
One computer to another in a global network (i.e. internet)
276
Magnetic storage spins discs....
about 7000 rpm
277
Can be written to or read from and data can be changed by the user or the computer
RAM
278
Name facts about brute force attacks
No sophistication, time consuming, often uses wordlists
279
Denary is base __
10
280
In a flowchart, what is a subroutine?
Subroutine call that will relate to a separate flowchart
281
What does dual layer mean?
Two layers are sandwiched, one is slightly deeper, DVD/Blu-ray reads both
282
Name 3 types of buses in CPU
data bus, control bus, address bus
283
Convert 01101 to denary
13
284
Magnetic storage stores data on
discs or platters
285
____ testing is testing it by yourself, ______ is testing on a target audience
Alpha is testing it by yourself, Beta is testing on a target audience
286
What is simplex
data sent in one direction only, example is computer to printer
287
What hacking is when a hacker tries all combinations of characters?
brute force attack
288
FETCH - Where do instructions go after MDR?
CIR
289
Binary counts in multiples of _______
2
290
Packets are made up of
Header / Payload (Data) / Trailer
291
What are the key questions to consider when reviewing automated systems?
What is the system? / What sensors are used? / What do the actuators do? / What does the computer/microprocessor do?
292
What does PDLC mean?
Programming development life cycle
293
How do you add two binary numbers?
Write them like column addition sum, start from right side and carry any 1+1 otherwise keep value
294
What is an overflow error?
When a number is too big to be stored in (value) bits
295
Maximum number value of 8 bits is
255
296
Maximum number value of 12 bits is
4096
297
Maximum number value of 16 bits is
65535
298
Binary logical shifts mean
moving a number to the left or right
299
A left logical shift means ________ the number by 2
multiplying
300
A right logical shift means ________ the number by 2
dividing
301
During logical shifts, empty positions are filled with
zeros
302
Left shift this binary number 1 place: 0010 << 1
100
303
Left shift this binary number 2 places: 0010 << 2
1000
304
Right shift this binary number 1 place: 1011 >>> 1
101
305
Right shift this binary number 3 places: 1011 >>> 3
1
306
Two's complement allows
representing negative integers
307
In two's complement the left-most bit is changed to a _____ value
negative
308
The left most value is changed to a negative number in _____ _________
two's complement
309
Bitmap images are made of
pixels
310
pixel =
picture element
311
Each image is made up of a _________ matrix of pixels
two dimensional
312
Pixels are represented in
binary
313
Bitmaps are stored as a series of
binary numbers
314
Black and white images only require ______ per pixel
1 bit
315
In 2 bit pixels, each pixel can be
1 of four colours
316
Number of bits used to represent each colour is called
colour depth
317
8 bit colour depth means each pixel can be _____ colours
256
318
Modern computers have ___ bit colour depth
24
319
Image resolution means
number of pixels that make up an image
320
Lower image resolution means
Less image detail
321
Pixelated means
Fewer pixels to represent the image
322
Whats the main drawback of using high resolution images?
Increase in file size
323
Unicode and ASCII code are _________ _____
character sets
324
What represent letters numbers and characters found on a standard keyboard?
Unicode or ASCII
325
Whats a disadvantage of ASCII?
Not suitable for most languages around the world
326
What character set code can represent all languages of the world?
Unicode
327
Unicode is...
universal, efficient, uniform, unambiguous, supports up to 4 bytes per character
328
Amplitude =
loudness of sound
329
Sound is a____________
analogue
330
Sound waves need to be __________ to be stored in a computer
sampled
331
Sampling means measuring the ____________
amplitude
332
Sound conversion is done using
ADC (analogue to digital converter)
333
Sampling happens at
regular time intervals
334
bits per sample =
sampling resolution / bit depth
335
Sampling rate =
number of samples per second (in hertz, Hz)
336
How is sampling used to record a sound clip?
amplitude is determined with sampling rate, each sample encoded as series of binary digits
337
Using more bits to sample amplitude =
more accuracy of sampled sound
338
Higher sampling rate or larger resolution =
better quality sound, larger file size
339
Name 3 drawbacks of larger sampling resolution when recording sound
larger file size, takes longer to transmit/download data, requires greater processing power
340
Name 3 benefits of larger sampling resolution when recording sound
larger dynamic range, better sound quality, less sound distortion
341
What has 16-bit sampling resolution and 44.1kHz sample rate?
CDs
342
What does the system clock do?
Defines the clock cycle that synchronises all computer operations
343
Which bus transmits timing signals ensuring sychronisation?
Control bus
344
What defines the clock cycle that synchronises all computer operations?
System clock
345
What happens if you increase clock speed?
Processing speed is also increased - but NOT NECESSARILY overall performance
346
3.5 Ghz is equivalent to
3.5 billion clock cycles per second
347
What hardware factors improve overall performance of a computer?
Number of cores, size of cache and speed of clock can affect performance of CPU
348
How do you increase processor speed (but not necessarily overall performance)?
Increase clock speed
349
What happens if you increase Number of cores, size of cache and speed of clock?
Improve overall computer performance
350
Increasing clock speed is known as
overclocking
351
Overclocking higher than design limits leads to...
unsynchronised operations, crashing, overheating of CPU
352
If your computer has unsynchronised operations, crashing and overheating of CPU, what might be the cause?
Overclocking
353
Unlike RAM, cache memory is located in
the CPU
354
Cache memory has ______ access times than RAM
faster
355
What has faster access times than RAM
cache memory
356
What does cache memory store?
frequently used instructions and data
357
When a CPU wants to check memory, it checks ______ first then _____
cache first, then RAM
358
Larger cache memory =
better CPU performance
359
The use of a different number of ______ can improve computer performance
cores
360
One core is made up of an ____ , ____ ___ and _______
ALU, control unit and registers
361
What's made up of an ALU, control unit and registers?
A core
362
Using more cores means less need to increase ______ ________
increase clock speed
363
What's a factor in increasing the number of cores?
CPU needs to communicate with each one which can reduce performance
364
What are cookies?
Small files or code stored on a user's computer
365
What are small files or code sent from a webserver and stored on a users computer
Cookies
366
Everytime a user visits a website, the site checks if it has set _______ on their ________ before
Everytime a user visits a website, the site checks if it has set cookies on their browser before
367
What are the two types of cookies?
Session and persistent
368
What are session and persistent types of ?
Cookie
369
Which cookie is temporary and don't collect or store user information?
Session cookies
370
Name two facts about session cookies
Temporary, don't store/collect user info
371
Which cookies cease to exist when a browser is closed?
Session cookies
372
Session cookies _____ to ______ when a browser is closed
cease to exist
373
What are session cookies used for?
Temporary shopping baskets
374
Which cookies are used for temporary shopping baskets?
Session cookies
375
____ cookies are stored on the hard drive of a users computer
persistent cookies
376
Which cookies have an expiry date or stay until deleted?
persistent cookies
377
Which cookies remain even after the browser is closed?
persistent cookies
378
What are persistant cookies used for?
Allow website to remember usernames, passwords, emails, baskets, preferences
379
What kind of user preferences do cookies hold?
language, currency, login
380
Payments can be sent digitally over the internet using...
Credit cards, Paypal, Apple Pay, Kakaopay and more!
381
Digital payments over the internet are secure because they are
Encrypted
382
The central authority for currencies are
banks
383
Banks are the ________ _________ for currencies
central authority
384
An example of a central bank is....
Bank of England, Bank of Korea
385
Examples of cryptocurrencies are
bitcoin, dogecoin, ethereum, cardano
386
bitcoin, dogecoin, ethereum, cardano are examples of
cryptocurrencies
387
Bank of England and Bank of Korea are examples of
central banks
388
Cryptocurrency has no ________ _________
central authority
389
What has no central authority for payments?
cryptocurrencies
390
No central authority as also called
Decentralised
391
Decentralised
means no central authority
392
Cryptocurrency payments over the internet are secure because
they are encrypted
393
Payments are made for cryptocurrencies using...
blockchain
394
Blockchain is how _________ payments are made
Cryptocurrency
395
A blockchain is like a
digital ledger or list of all records of payment
396
Blockchains record...
All payments with time and date stamps
397
Once added to a blockchain, records....
cannot be changed
398
Blockchains are accessible by...
every connected computer
399
A single 1 or 0 is called a
bit
400
How many bits in a byte?
8
401
How many bits in a nibble?
4
402
1 kibibyte = 1 KiB = how many bits?
1024
403
1 mebibyte = 1MiB = how many KiB?
1024
404
KiB =
Kibibyte
405
MiB =
Mebibyte
406
GiB =
Gibibyte
407
TiB =
tebibyte
408
PiB =
Pebibyte
409
EiB =
Exbibyte
410
How many mebibytes in a gibibyte?
1024
411
How many gibibytes in a tebibyte?
1024
412
How many tebibytes in a pebibyte?
1024
413
How many pebibytes in an exbibyte?
1024
414
Order the data units from SMALLEST to largest
bit, nibble, byte, kibibyte, mebibyte, gibibyte, tebibyte, pebibyte, exbibyte
415
Order the data units from LARGEST to smallest
exbibyte, pebibyte, tebibyte, gibibyte, mebibyte, kibibyte, byte, nibble, bit
416
What's missing from this list of data units - bit, ______, byte, kibibyte...
nibble
417
What's missing from this list of data units - mebibyte, ______, tebibyte
gibibyte
418
What's missing from this list of data units - gibibyte, ______, pebibyte
tebibyte
419
What's missing from this list of data units - nibble, ______, kibibyte
byte
420
We use mebibyte, gibibyte etc, instead of megabyte, gigabyte because...
Mebibyte, gibibyte (etc) system of units is more accurate
421
How to calculate size of image file?
multiply image resolution and colour depth
422
How to calculate size of sound file?
multiply sample rate , resolution and length of track
423
How to calculate image resolution?
Multiply height by width in pixels
424
What are sensors?
Input devices which read or measure physical properties from their surroundings
425
Examples of sensors
temperature, pressure, pH, humidity
426
Real data in nature is a________
analogue
427
What does analogue mean?
Constantly changing doesn't have a single discrete value
428
Analogue data is converted to _______ format
digital
429
Analogue converted to digital using _______
ADC Analogue to digital converter
430
Sensors send out c______ values
constant
431
What analyses the input from sensors?
microprocessor
432
Temperature sensor
measures temperature of surroundings
433
Moisture sensors
measure water levels, e.g in soil
434
Humidity sensors
measure amount of water in the air
435
Light sensors
use photoelectric cells that produce output based on brightness of light
436
Infrared (active) sensors
uses invisible beam of infrared radiation with detector. If beam broken, then change has happened
437
infrared (passive) sensors
measure heat given off by an object
438
Pressure sensors
Transducer that generates electrical currents depending on pressure applied
439
Acoustic/sound sensors
Microphones that convert sound into electric signals/pulses
440
Gas sensors
measure gas being monitored, e.g. oxygen or carbon dioxide
441
pH sensors
measure acidity changes, e.g. in soil
442
Magnetic field sensors
Measure changes in magnetic fields
443
Accelerometer
Measure acceleration and motion of an application, e.g. change in velocity
444
Proximity sensor
Detect presence of nearby object
445
Flow (rate) sensor
Measure flow rate of moving liquid or gas and produce an output based on amount passing over sensor
446
Level sensor
Use ultrasonics (for liquid changes) or capacitance/conductivity (for static levels)
447
Example uses of temperature sensors
control heating system, control/monitor a chemical process, control/monitor temperature in a greenhouse
448
Example uses of moisture sensors
control/monitor moisture levels of soil in a greenhouse
449
Example uses of humidity sensors
measure humidity in a building, factory, greenhouse
450
Example uses of light sensors
switching on street lights on or off depending on light levels, switch on car headlights when it gets dark
451
Example uses of infrared sensors (active)
turn on car windscreen wipers when it detects rain, security alarm when intruder breaks beam
452
Example uses of infrared sensors (passive)
security alarm (detects body heat), monitor temperature inside a freezer
453
Example uses of pressure sensors
weighing of lorries at weighing station, measure gas pressure in a nuclear reactor
454
Example uses of acoustic/sound sensors
Security system - noise of footsteps, detect sounds of liquid dripping in a leak
455
Example uses of gas sensors
Monitor pollution levels at an airport, monitor oxygen and carbon dioxide levels in a greenhouse
456
Example uses of pH levels
Monitor/control acidity levels in the soil in a greenhouse, control acidity levels in a chemical process
457
Example uses of magnetic fields
detect magnetic field changes in mobile phones in smart phones, anti-lock braking systems in cars
458
Example uses of accelerometers
in cars for deploying airbags in a crash, used by phones to detect portrait/landscape
459
Example uses of proximity sensors
Detect when face is close to smart phone
460
Example uses of flow (rate) sensors
used in respiratory devices and inhalers in hospitals, measure gas flows in pipes
461
Examples of level sensors
monitor levels of petrol in gas tank, leak detection in refrigerant in AC units
462
How are sensors used in a monitoring process?
Sensors send signals to microprocessor, converted using ADC, checks against stored values, if outside value set, alarm sounds or message sent
463
How are sensors used in a control process?
Sensors send signals to microprocessor, converted using ADC, checks against stored values, if outside value set, signal sent to control values/motors etc, output checked against other sensors
464
Examples of monitoring sensors
monitoring of patient vitals in hospital, monitoring of intruders in security system, checking temperature levels in car engine, checking pollution in a river
465
Examples of control sensors
Turning on and off street lights at day/night, control temperature in heating/AC, control chemical process
466
What is virtual memory?
Type of memory created for temporary use and used as an extension of RAM
467
Where is virtual memory created?
In an area of the hard drive
468
Why is virtual memory needed?
Computers have a limited amount of RAM and need additional resources to run programs users need
469
What happens when RAM gets full and has more instructions to run?
It transfers some data to virtual memory until its needed
470
What's data transferred from RAM to virtual memory (and back) called?
a page/pages
471
______ are moved to virtual memory when not needed then transferred back when processed
pages
472
What's memory created for temporary use and used as an extension of RAM?
virtual memory
473
What's created in an area of the hard drive to support RAM?
virtual memory
474
What are pages in memory?
data that's transferred from RAM to virtual memory and back
475
What are the key parts in the virtual memory process?
RAM, pages, virtual memory and hard drive
476
What are benefits of virtual memory?
Programs larger than RAM can be processed. No need to waste RAM. No need to buy more RAM
477
What's thrashing?
In virtual memory when swapping large amounts of pages, high rate of head movement reduces processing speed
478
What are privacy settings?
Controls available on web browsers, social networks and web sites desinged to limit access to personal profile
479
What controls available on web browsers, social networks and web sites desinged to limit access to personal profile?
Privacy settings
480
What kind of privacy settings are there?
Do not track, saving payment methods, safer browsing option, storing browser history/cookies, app settings like location data
481
What are these settings called? Do not track, saving payment methods, safer browsing option, storing browser history/cookies, app settings like location data
Privacy settings
482
What are proxy servers?
Proxy servers act as an intermediate between the user and web server
483
P______ s_______ act as an intermediate between the user and web server
Proxy servers
484
What are features of proxy servers?
Filter internet traffic, block access to websites, hide IP address, block requests from IP, prevents direct access to web server, helps prevent DoS & hacking
485
What do these features describe? Filter internet traffic, block access to websites, hide IP address, block requests from IP, prevents direct access to web server, helps prevent DoS & hacking
Proxy servers
486
A firewall can either be s_______ or h________
software or hardware
487
What is the purpose of a firewall?
Sits beween a users computer and external network - filters information in or out of a computer
488
Firewalls are the p________ d________ for computer systems to help protect it from hacking, malware, phishing and pharming
primary defence
489
Firewall main tasks are...
Examine traffic between users computer and a network, checks if incoming/outgoing data meets criteria, can block traffic that doesn't meet criteria, logs all traffic
490
What's main tasks are: Examine traffic between users computer and a network, checks if incoming/outgoing data meets criteria, can block traffic, log traffic?
Firewall
491
What is artificial intelligence?
The development of programs to simulate human behavior.
492
What are types of AI?
image recognition, speech recognition, natural language, computer games, diagnostic systems
493
What is image recognition?
identify objects or people in an image
494
What is speech recognition?
Identify words spoken by humans and store them
495
What is natural language?
To receive a command or instruction that is not in a set format and perform the required task (e.g. Siri question)
496
What use is AI in computer games?
to move elements or characters independently based on the environment
497
What is a diagnosis system in AI?
e.g. to diagnose medical problems
498
What are the features of AI programs?
collect data, programmed rules, ability to reason, ability to learn and adapt
499
What is collecting data in AI?
programs need data input - data might come from users or from sensors
500
What are programmed rules in AI?
Programs use rules to make decisions
