The Student Room Group

OCR GCSE Computer Science J276/01 13th May 2019- Morning UNOFFICIAL MARK SCHEME

Scroll to see replies

Reply 380
Caeser cipher had me deadddddd df they tryna do to our brains
from the questions jayjayhilts provided ive answered:
if anyone can add answers or questions then please do
these questions are not in exact order
( PLEASE NOT IF YOUR ANSWER IS NOT HERE THEN IT DOES NOT MEAN IT IS WRONG)

1- Fill in blanks on CPU (5 marks) - Central Processing Unit, Instructions, Memory, Arithmetic Logic Unit, Control Unit
2- Why having dual cores might be better (2 marks) - can theoretically perform twice as many instructions per second as instructions are executed simultaneously ( might be better as some programs are sequential meaning only one core is neccessary)
3- Why having more cache is better (2 marks) - cache is very fast, close to cpu, bigger size cache = more frequently used data can be stored meaning instructions can be executed faster
4- RAM/ROM tickboxes (5 marks) - both store data, ram is volatile, rom is non volatile, ram stores currently running programs, rom stores bios
5- Example of Solid State device and primary or secondary storage (2 marks) - USB ( Memory Stick) - Secondary storage
6- Solid State vs optical (8 marks)
Solid State
- less portable in comparison to optical drive
- faster
- higher cost per gb
- more reliable
- more robust/durable ( no moving parts)
- bigger capacity
Optical Drive:
- more portable
- lower cost per gb
( conclusion of either ssd or optical is okay as long as points support it)
7- GB -> MB conversion (2 marks) 5000 or 5120
8- File management uses (3 marks) - organising files, creating file extensions for programs to open files, modifiying deleting/removing files
9- Compression (4 marks) - compressing reduces file size = quicker download/upload to the internet - lossy - loses data cannot be decompressed to its original form
lossless - reduces file size less compared to lossy however can be decompressed to its original form
10- Utility software two examples (2 marks) - encryption, backup, compression, defragmentation
11- Embedded system Smartwatch v laptop and why (3 marks) - watch ( embedded system is a computer build into another device ) watch has a computer that has a specific purpose, laptop is for multiple purposes
12 - ascii ( caesar cipher question)
its not letting me put the answers here
13- Star topology diagram (3 marks) - switch in the middle - spider diagram - 4 laptops a printer and a server connected to the switch
14- Use of a switch (2 marks) - central point of communication, directs and coordinates data flow on the network
15- Why is it bad if get into confidential files (3 marks) - malware- could infect computer which can affect the whole network
sensitive data, personal informaiton can be leaked etc
16- protecting on a network (4 marks)(i think? or was it 3?) firewall, controls data that enters and leaves networked computer, flags potential threats
pentration testing, to identifiy vulnerabilities and fix them
17- protocols (4 marks)
18- IP address/URL/webserver (5 marks)
So basically you had to describe the relationship.
Urls and ip’s are related to eachother and stored on DNS’s ( Domain name System )
Once u enter the url the web server sends a request to the local dns to find the relating IP adress so that a connection can be established. If the dns cant find it the dns sends a request to another dns and this repeats till the ip is found and sent back to the web server.
The relationship between them is a client server relationship.
The web server acts as a client when it sends s request for the IP, the Dns can act as a client or a server. It is a server when it processes and sends back the Ip address but when the dns has ro contsct other dns’ the orginal dns becomes a client and the other dns becomes the server
19- Why use layers( applicaiton and network) (3 marks) self contained, can change one without affecting other layers, layers are group of protocols, protocols are a set of rules dor data transmission, layers as a whole manage data transmission over a network. TCP is responsible for ensuring packets are sent/recieved as well as for splitting up data into packets
20- How encryption works (2 marks)(I think? or was it 3?) - masking of data to prevent unauthorised access, only owner knows the key
21- Why good for environment to release game online (2 marks) - no need to use materials to create a case for the game - case can be made out of raw materials ( non renewable resources ) selling game online saves material.
22- Why proprietary is better than open source (2 marks) - proprietary allows for money to be made, source code is private therefore competitiors cant see the code.
23- Difference between RAM and flash (1 mark) - ram is volatile flash memory is not
(edited 4 years ago)
I found the paper quite easy...just the question about the pseudocode tripped me up.
Original post by ShyB
I found the paper quite easy...just the question about the pseudocode tripped me up.


Think a lot of people got stumped by that one, probably one of the hardest if not the hardest question on the paper tbh
On the second page with the RAM and/or ROM tick boxes does anyone know what was in the tick boxes. Am I right the first box was both RAM and ROM or am I wrong?
I wrote for the Hamish’s computer question:
- Anti-Virus/Malware
- Password Protect Computer / Files

Do you think that’s right?
Original post by Sheikh._1
I said anti-virus and physical access to the laptop


na bro, i put Firewall and anti-virus
Original post by ynxg_kami
I swear its the DNS checks if that server has the Ip address that matches that URL and if it doesn't it goes up to another DNS server and it keeps doing that until the IP dress has been found so the user can be directed to that website and if the IP adress of the URL is not found then error message occurs


I wrote about the browser sending a request for the IP address to the DNS first and then a request to the web server for a copy of the website that has to be loaded. I also talked about packet switching in the answer
Wasn't question 21 about the impacts? I put that by creating a new version of the video game people may not want to buy the old one and so destroying the old one's will result in pollution and build up of e-waste.
yea ur right
Original post by Metriczs
On the second page with the RAM and/or ROM tick boxes does anyone know what was in the tick boxes. Am I right the first box was both RAM and ROM or am I wrong?
Yo what did u out the difference between RAM and Flash memory question? I put That RAM is a primary storage and Flash Memory is secondary storage
i wrote that and its right i searched it up

Original post by sonu2003
Yo what did u out the difference between RAM and Flash memory question? I put That RAM is a primary storage and Flash Memory is secondary storage
What did you guys get for 5GB to MB?
I got 5000MB but my friend says its 1 Million. I even checked on the internet. It Says 5000MB.
(edited 4 years ago)
I put that ram is volatile and that flash memory is non-volatile. Is that correct?
Original post by sonu2003
Yo what did u out the difference between RAM and Flash memory question? I put That RAM is a primary storage and Flash Memory is secondary storage
It's 5000MB because to get from GB to MB you have to times by 1000. Well done!
Yh that would be correct, Well I think so anyways Lol
:smile:
Original post by penguinify
I put that ram is volatile and that flash memory is non-volatile. Is that correct?
Great thanks :smile:
Original post by sonu2003
Yh that would be correct, Well I think so anyways Lol
:smile:
I wrote install anti-malware software and didn't know what to write for the second one so I wrote about firewalls.
Did I made a mistake on firewall or am I right I honestly don't know....????????????
Original post by 2018Y11Student
I wrote for the Hamish’s computer question:
- Anti-Virus/Malware
- Password Protect Computer / Files

Do you think that’s right?
Original post by jstephens1605
For the 5 marker on IP, URLs and Web servers did anyone else just describe how DNS works?


I said how the protocol at the start of the URL is used to access information from the web server and the DNS stuff
Dude I multiplied 1024 by 5 because there is 1024 MB in 1 GB and I got 5120 MB
Original post by Keri00Summers
What did you guys get for 5GB to MB?
I got 5000MB but my friend says its 1 Million. I even checked on the internet. It Says 5000MB.
I don't know how to tell her that she lost 2 marks...

Quick Reply

Latest