Address, Data and Control Buses

[@chronicsnail6675]

A bus is a pathway to which data is transferred; they come in two types 64 bit or 32 bit. A useful metaphor: A bus is a motorway and the bits are the individual lanes so on a 64-bit bus more data can travel across a wider range, and of course the traffic is the data. A Bus can be unidirectional or bidirectional, meaning it can move data from and to (unidirectional) or either to or from (bidirectional). Types of Buses: - Address bus: sends a memory address FROM the CPU TO the RAM, the CPU is asking which address is the next piece of data to be executed is located. = Unidirectional - Data bus: Once the address bus has specified the location the RAM can now send and receive information to which the CPU is now executing the data. = Bidirectional - Control Bus: Carries commands and status messages which can tell the RAM to backup data or to prioritise this instruction rather than this instruction. = Bidirectional

[@paulfernandes8934]

thank you stalin, very cool

[@dudipallabharathkumar5973]

Cool

[@chronicsnail6675]

@Reazar87 i passed my comp sci and still dont know shit about how a computer works lmao

[@siddharthkumaryadav3356]

@@chronicsnail6675 😂😂😂😂LOL. From where u are

[@houseplay4569]

Thank u

[@NKJFVIDS]

Nothing to do with the video as such. But you single handedly saved me in that test today because my teacher was useless. I would like to give you my sincere thanks for teaching me a 2 year course in like 4 hours. Thank you so much, true life saver right here. Just about everything in those videos came up lol. Anyway thanks again

[@MrBrownCS]

Glad to help, cheers :)

[@alimalikashraf7623]

You are Alphonse great, everything you taught came up in the exams. Lets hope paper 2 is the same

[@swethadeepak3029]

SIR' I LIKED THE WAY YOU EXPLAINED THRO SIMPLE DIAGRAMS, AND VERY IMPORTANT USE/FUNCTION, VARIETY OF "BUS CONDUCTOR LINES" USED IN COMPUTERS. VERY WELL DONE. THANK YOU, VATSA INDIA

[@coffee_bean__]

Thank you sir, after watching your AQA playlist, you have saved my GCSE. *salute*

[@jonathannwanosike3510]

yeah me too bro

[@coffee_bean__]

Jonathan Nwanosike oh look who it is ;)

[@FSteptoe]

Good luck tomorrow?

[@hmwh4t]

Coffee Bean this ain’t aqa

[@Zaptrap101]

Thank yo so much, I was really confuse about what address bus is, you explained in such a way that it is easy to understand,

[@shaenorelation7175]

thank you! very informative even if it's after exam

[@aimeeayoga503]

I love ur videos a lot I never used to fully understand most of the theory work but thanks to u I moved from a 4 to a 7 in my mock paper 1 😩now I just need to work on my coding skills which keep bringing me down n hope I can pass the real GCSE in 11 days

[@MrBrownCS]

Fantastic! You don't need to be a brilliant programmer for the exam - just need to understand the programming theory that my videos cover

[@colleensdan]

Who's here the morning of the exam? 😂

[@dinodee6938]

✌️

[@meoovlogs8845]

It’s in 30 minutes

[@dinodee6938]

how'd it go 😂

[@siddharthkumaryadav3356]

@@meoovlogs8845 how did it go

[@awake_live]

Starts in 30 seconds

[@jeremeysmith177]

if you guys want a top grade, i would advise you to do at least two paper and go through the mark scheme

[@pavithirapakeerathan4929]

Thank you so much because i do have my gcse computing on monday and i think it's help me lot😀😀

[@CoreStudios.]

Pavithira Pakeerathan same here gd luck

[@pavithirapakeerathan4929]

da ligit midget thank you and good luck for you as well

[@ohhcarbonz_9817]

Thanks you’re actually a life saver paper 2 was piss easy thanks to your vids and I think I managed to cram a ton of keywords in ❤️❤️

[@mantle7395]

Yeah, that paper was too easy. Rip the grade boundarys, I wonder how they will look with paper 1. Paper 1 was quite challenging.

[@ohhcarbonz_9817]

Mantl3 I recon that they still will be quite low tbh that paper was easy but I bet people lost a lot of marks not using subject terminology

[@mantle7395]

True

[@tobu3816]

@@ohhcarbonz_9817 How did u do?

[@btshyyh]

cramming rn best of luck for tomorrow everyone

[@ellieyip9195]

Noelleh 😪😪 I need more than luck 😭😭

[@edwardouzman4115]

Cheers, good luck man

[@thereseenjoyer]

same good luck

[@TheGamingDenn_]

what did you end up getting?

[@godofgold1531]

Hi Sir, Can you please do a Walkthrough with Paper 1 GCSE. Thanks :D

[@alessandroporfirio1910]

Very good lecture! Thank you!

[@kammy503]

do we need to know this in the aqa spec it says: A bus is a collection of wires through which data is transmitted from one component to another. Main memory will be considered to be any form of memory that is directly accessible by the CPU, except for cache and registers. so do we need to do different types of buses and their functions or just a general definition btw awesome videos

[@chronicsnail6675]

That is the general definition for a bus, yes.

[@gameitwright7821]

Please add this to the Edexcel playlist, I think it is relevant for that exam board.

[@gameitwright7821]

Sorry, I checked and it's already there. I clearly just don't pay enough attention. Thank you!

[@pranavmadhukar12]

Thank you very much! Quick question - So, an 8 bit computer will have 8 wires in each of the 3 buses right?

[@fatboy3677]

Very helpful... thank you sir

[@onlyshorts6837]

Which bus does we use to measure cpu performence ??

[@obamascock2169]

Im wondering about the bus lanes, you said that a 64 bit computer would need a bus that is 64 bit. What about Parallel Buses?

[@mlab3051]

Control bus is bidirectional? I doubt that. I think control bus is unidirectional but some go from CPU to register and some go from register to CPU.

[@amazingf1238]

videos 12-26 are repeated on playlist paper two and are on both papers!

[@kamo8741]

Is this applicable for OCR A-level Computer Science? I wonder if this playlist is enough to learn everything I need to know for my upcoming PPE.

[@tigpooter3077]

What do you feel the grade boundaries will be for the new gcse? My school set it really high (80% for an 8, 90% for a 9) I just want your opinion on if you think it'll be set really high or low. I know generally for computer science the boundaries have been low but I don't know for this course if they'll change it up.

[@MrBrownCS]

I wish I knew! I'd imagine they will be lower than that, but that's a guess - and it's better to assume they will be high to be on the safe side!!

[@tigpooter3077]

Computer Science Tutor I guess that's true. Thank you 😊

[@elmo7232]

hey sir, do you think JUST watching your videos and exam questions will suffice for me to get at least an 8?

[@MrBrownCS]

It's impossible to say, because it will be for some people but not for others. If you understand everything on the spec, then there's a big chance you'll get an 8. How you get there is up to you

[@wadman1804]

Hi, our school just received a second set of specimen papers. If i send them to you would it be possible for you to do a paper walk-through like you did with the other specimen papers. The exam is on Monday!

[@MrBrownCS]

Thanks but there's not enough time I'm afraid - the mark scheme should be fairly straightforward

[@quantumzerelth9140]

Just done computer science exam 2018.

[@DatGuyExo]

same here; hope ya did well ^.^

[@quantumzerelth9140]

DatGuyExo wont lie. It was kinda easy.

[@zeegamer6743]

very good video

[@kookieskosmos8160]

morning of the exam!!

[@siddharthkumaryadav3356]

How did it go

[@jordog3550]

Hello Mr Brown, im trying to learn computer science for alevels as i didnt do it for my GCSE's, do you think that i can understand it in two weeks?

[@MrBrownCS]

In theory - while I think it's a good idea to spend some time to familiarise yourself with the GCSE content before you begin, your teacher should go over the content which overlaps between the GCSE and A Level when it's being taught. Not everything in the GCSE is required in the A Level, so just bear that in mind

[@jordog3550]

@@MrBrownCS Oh wow that's a relief, would you mind advising me on certain topics to learn in these 2 weeks please?

[@gameitwright7821]

Thank you this really helped me but I don't get how when at the start you have the 3 buses on the screen and you say for a 64-bit computer, only 2 of them would need 64 lines. However, wouldn't all of them need 64 lines if it was a 64-bit computer?

[@MrBrownCS]

Oh, I was referring to the control bus which doesn’t strictly need that many (though it may do) because it’s used a little differently

[@gameitwright7821]

Computer Science Tutor ok thank u

[@havimar7574]

Thank you for your videos! Have been really amazing for my last minute revision! Is it possible for you to quickly go over my pseudocode task for CIE IGCSE JUNE 2018 PAPER 2.... For our exam we need to be able to understand pseudocode and I am struggling .... Any help will be greatly appreciated!

[@crimsonchaos6685]

Can you go through a Unit 2 WJEC A level computer Science paper. Specifically section B if you could do it on python :)

[@themirestudios3326]

Hi - love your videos and I have my exams on Monday so thanks for the help but was wondering whether my answers are too detailed because I have been memorising of a text book and doing a work book and some of the answers I write are much more detailed than the ones in the answers of the workbook. The workbook is for edexcel and everything but Im worried that my edexcel exam may not accept my answers cause its not in the mark scheme. Would they accept it if it was technically right but more detailed than expected? Thanks in advance

[@MrBrownCS]

The examiners are subject specialists so they'll know when you're correct. You'll learn a lot about exam technique as you go through the GCSEs and you won't be perfect on the first exam, but you have to look at how many marks each question is worth - often you can guess what they want. I would always write too much but eventually I think being more concise became my biggest skill, so it's worth trying to adapt your approach slightly

[@themirestudios3326]

ok thanks - really appreciate your help

[@siddharthkumaryadav3356]

@@themirestudios3326 How did it go.

[@themirestudios3326]

@@siddharthkumaryadav3356 I got a 9 in the end so it went great

[@siddharthkumaryadav3356]

@@themirestudios3326 O that's good I don't know about GCSEs so much so i had to Open Wikipedia to understand what 9 means 😅😅.

[@Wenedi]

Btw How is an algorithm question asking to create a program which changes Mb to bytes a 6 marker?!? (Talking about todays exam)

[@snayk4773]

K1TT3N lmao ikr it was probably the easiest six marker ever

[@alimalikashraf7623]

it was pretty easy tho, but i think they wanted to catch people of guard with an algorthim question.

[@siddharthkumaryadav3356]

Which exam

[@benjaminp.skinner2543]

Thank you so much!

[@sabrinatahir3545]

Why read line for control bus is 0 always?

[@tigpooter3077]

Woukd you make a video commenting on today's exam?

[@nine108]

Tbh honest bohunt is best -harvey T

[@y__1330]

Is this for OCR? Please reply, im cautious

[@MrBrownCS]

It doesn't say anything about it on the spec, feel free to revise it if you'd prefer :)

[@y__1330]

Computer Science Tutor thanks a ton

[@_mar1]

Why is this not in the specification?

[@AndyThomasStaff]

ok but WHY do computers have busses why can't components plug directly into each other?

[@MrBrownCS]

A bus is just a wire, so that's like saying why can't your computer just plug directly into the wall socket. Well, it does, just with a longer wire than absolutely needed (but we need a wire for electricity to flow through). In terms of why they are split up into these 3, it's mostly about efficiency, as data can move about in parallel, not having to wait its turn to go through a single bus.

[@heatherlara4137]

is this a level or gcse? because the playlist says a level but you talk about gcse

[@MrBrownCS]

It was made for GCSE but it overlaps with A level

[@johnkramer5886]

Thank you!

[@siddharthkumaryadav3356]

Waoh u don't need to thanks 😂😂.

[@emilsdaksa2712]

Thanks.

[@JudahDaniels]

Watching all your videos on 1.5x speed xD

[@irmanij1256]

same here

[@Haywirezen]

What spec is this for?

[@MrBrownCS]

Edexcel GCSE

[@Haywirezen]

Computer Science Tutor okay thx 😊

[@Haywirezen]

Revision1209481029480909 ah okay I am doing OCR

[@MrBrownCS]

It doesn't say so explicitly (just says you need to know what a bus is) - but probably better to err on the side of caution, so I'll put it in the playlist

[@gaurav3794]

control bus is unidirectional. Isn't it?

[@MrBrownCS]

No, it's bidirectional

[@joshconquest6608]

oi oi whos here for tomorrow? xD

[@moshi_cs]

going through it all in 1 night

[@muhammadsyawal8673]

My teacher bring me here🤓

[@incognito7209]

Is a control bus the same as a control unit? Edit: The sooner you can answer this the better.

[@MrBrownCS]

No

[@incognito7209]

@@MrBrownCS Ok thank you

[@Wenedi]

Damn you small island with a 100 people!!! XD

[@Wenedi]

Worst question for me :/

[@snayk4773]

K1TT3N year it was a rubbish and unrealistic question

[@Isaac-ue7td]

Hopefully now I won’t flunk my GCSE’s

[@joeshroom5524]

Exam in one hour

[@why3994]

Who even uses 32 bit PCs in 2019 anyway 😂

[@JFalcon]

Bro my exam is in 10 hours

[@msmhooda3473]

in 2.5 hours.... now

[@v4l1AW]

I’m shitting

[@radoz146]

@@v4l1AW Come on boys we've got it

[@bettyswunghole3310]

Yikes! This is only GCSE level computer science? I thought this kind of thing was more degree level...

[@BethB6791]

4 mins to exam 😭😭😭😭

[@denzeldenzel8612]

anybody writing today?

[@wariouswarious7223]

How can my professor fail to explain such a simple shit???

[@xsdash]

accent is a bit hard to understand lol

[@Thereisnogreatersword]

GG

[@joeriley9740]

shush