1
Q
2 benefits of BCD
A
- easy to convert to denary - so less complex to decide
- easy for digital equipment to use BCD to display outputs
- can represent monetary values exactly
2
Q
describe the function of a WNIC
A
- provides and interface to a wireless network - as an antenna
- recieved analogue and converts to binary and vice versa
- checks transmissions of the correct MAC address - ignores others
- encrypts/ decrypts data
3
Q
what is meant by ethernet
A
- a protocol
- for data transmission over cables
- uses Carrier Sense Multiple Access/ Collision Detection
- data is transmitted in frames
- each frame has a source and destination address and error checking
4
Q
mesh topology
A
- all comps connected another device
- multiple routes between devices
- comps act as relays
5
Q
public vs private cloud
A
public
- services offered by a third-party provider over the public Internet
- Open to anyone
private
- Services offered either over the Internet or a private network
- Only available to select users
- It’s a dedicated system only accessible for an organisation
6
Q
role and function of a router
A
- receives packets from devices
- Find the destination using the IP address
- forwards packets to that destination
- Find most efficient path
- Act as a gateway
- acts as a firewall
7
Q
advantages of DRAM
A
costs less
higher storage density
simple design
8
Q
how does memory management organise and allocate RAM
A
- RAM is assigned in blocks
- dynamic allocation of RAM to programs
- Reclaims unused blocks
- Prevent overwriting
- Manages segmentation and virtual memory
9
Q
instruction groups in assembly language
A
data movement
input / output
arithmetic operations
10
Q
2 signals transferred on the control bus
A
- interrupt
- timing
- read/ write
11
Q
how do the CU system clock and control bus operate to transfer data
A
- clock gives out timing signals
- send along control bus
- to synchronise components
- CU initiates data transfer
- by generating signals that are send via control bus
12
Q
purpose of the CU
A
- to coordinate actions of other components
- to send / recieve control signals along the control bus
- to manage execution of instructions
- controls communications between CPU components
13
Q
causes of software interrupt
A
/0
array index out of bounds
14
Q
how the OS manages hardware devices
A
- installs drivers - to allow communication
- sends data to and from devices
- handles buffers - to ensure amooth transfer if transmit at different speeds
- managed interrupts
15
Q
how is data transmitted through USB
A
1 bit at a time
can by synchronous or asynchronous
USB3 is full duplex - earlier are half duplex
16
Q
how does the OS manage processes
A
- manages scheduling
- manages resources required eg allocating memory
- enables data sharing between processes
- resolves conflicts
- handles the queue
- allow multitasking - by handling priority and interrupts
17
Q
purpose of utility software
A
- to help users optimise the computer
- eg by making memory allocation more efficient, checking for faults ect
18
Q
2 benefits of DLL
A
- reduces memory requirement for program - only loaded when required
- maintenance isn’t done by programmer - automatically updated as it’s droefste from the program
19
Q
file management
A
- divides storage space into file allocation units
- allocated space to files
- creates directories
- specifies the file storage eg FAT NTFS
- provides file naming conventions
- controls access rights
- specifies tasks on a file eg open close delete copy create
20
Q
security vs privacy
A
security protects against loss
privacy is unauthorised access
21
Q
checksum
A
- is calculated from data before transmission
- is transmitted with data
- receiving comp also calculates using the same algorithm
- if they match no error - if they don’t an error has occured in transmission
eg sum bits /256 - round down *256 diff between this and the sum = the checksum
eg modulo. 11 - digits given wiegthing then added and /11 then the remainder is subtracted from 11
22
Q
+ of professional ethical bodies
A
- have ethical guidelines to follow - so people know the standards you gave
- people know you are reputable - may be requirement eg test for entry
- provides help eg legal support
- run training course - keep skills up to date
23
Q
how someone has acted unethically
A
didn’t act in best interest of the…
product
client
profession
company
24
Q
what does the system clock do
A
- synchronises operations - creates timing signals
- keeps track of date/ time
- proccesses operation in sequence
25
+ / - of satellites
+ allows access in rural areas
- more interference from weather
- more expensive to set up infrastructure
26
IPv4 vs IPv6
**IPv4**
4 groups of digits
each using 8 bits
seperated by .
decimal
**IPv6**
8 groups of digits
each using 16 bits
seperated by ;
hex
multiple 0000 > ::
27
components of a sound encoder
band limiting filter - removes high freq not detected by humans
ADC - converts analogue > digital
28
bit streaming +/-
+ dont need to wait for whole file download
+ dont need to store large files
+ no specialist softwrae needs for playback
- if low broadband/ small buffer video stops
- only acces when connected to internet
- can download viruses
29
thcik client +/-
+ more robust
+ clients have mroe control
- data integrity - many clients acces same data
- less secure
- all need to update invidiually
30
thin client +/-
+ cheaper to expand
+ sever offers security
+ central server
- reliant on server if breaks
- pricy at start - need to buy sever
31
bluetooth
radio waves
79 frequencies - (spread spectrum freq hopping)
2.45 GHz
devices automatically detect and connect
- slow
- low bandwidth
32
WiFi
uses spread spectrum freq hopping
+ faster
+ better range
+ better security
33
satelite levels
GEO - long distance telephoen and computer (35800km)
MEO - GPS (5000- 12000km)
LEO - mobile phone network (500 - 1500km)
34
class ranges (subnetting)
A - 0-127 - very large
B - 128 -191 - medium
C - 192 -223 - small
D - 224 - 239 - multi cast
E - 240-255 experimental
35
CIDR
classless interdomain routing
- improves IPv4 address range
- uses a suffix of 18b for netID and 15b for hostID
36
NAT
Network address translation
converts public to private IP - used on IPv4 to be able to reuse IPs on private networks at are already in use on public networks
37
URL
protocol://web address/ path/ filename
web address - domain host, name, type, country code
38
printers
39
extras in AL not MC
macros - sequence of instructions that cna be used more than once
symbolc names
comments
directives - instruction as to how to construct final MC eg how to use memory
40
a - cs
flashcards
Decks in class (30)
# Cards
-
chapter 1 - information representation59
-
chapter 2 - networks59
-
chapter 2 - internet28
-
3 - hardware48
-
4 - processor fundamentals29
-
4 - assembly language38
-
5 - system software39
-
- monitoring and control systems4
-
6 - security, privacy and data integrity45
-
7 - ethics15
-
8 - data bases40
-
9 - algorithm design + problem solving16
-
10 - data types and structures24
-
12 - software development29
-
13 - data representation29
-
14 - communincation47
-
15 - hardware33
-
16 - system software + virtual machines77
-
17 - security32
-
18 - AI37
-
19 - computational thinking49
-
20 - further programming (pyhton files)39
-
20 - further programming21
-
psuedocode26
-
files / records4
-
mocks dont know40
-
jan mocks dk36
-
paper 1 dk58
-
paper 2 dk31
-
paper 3 dk32
