CSSA IPT 2003 Trial (3 Viewers)

[Huy]

Originally posted by cyrax83
That 9600 bps question had me a bit stumped too.. but i worked it out, i put 3.4 seconds because :

4KB = 4*1024 Bytes = 4096 Bytes
4096 Bytes = 4096 * 8 Bits = 32768 Bits

Since modem is 9600 bits per second
32768 / 9600 = approx 3.4 seconds

How could you do that in an exam with no calculators!

I wrote 4.3s in the exam, but my way of working it out was:

9600 bits per sec / 8 bits per byte = 1200 kilobytes per sec
1200 / 1024 bytes = 1.171875 kilobytes per sec
4 KB / 1.171875 kilobytes per sec
= 3.4133333333333333333333333333333

that's how i usually work things out, anyway,
for example:
56K = 56,700 bps
56,700 bps / 8 = 7087.5 Kbps
7087.5 Kbps / 1024 = 6.92138671875 KBps (Kbytes)

Theoretical bandwidth for 56K is about 7KB/s.
I should have started off by knowing this, (slipped my mind),
then dividing 56K by 9.6K
(about 6)

Dialup downloads at 7KB/s (tops)
meaning for a 9.6K modem, it'll be about 1/6th of 56K,
7/6 is roughly 1.1KB/s

4KB file, going at a max of 1.1KB/s
4 / 1.1 = ~3.6
Which is close enough to 3.4 secs, moreso than 4.3 seconds

 

[...]

oh fuck...

 

[skip to my lou]

nah i knew it was 3
coz if you look at 9600bps
thats BITs per second
change that into bytes by dividing by 8
you get 1200
and thats higher than 1024
in other words it has to be less than 4seconds

i dunno i use my logic on that one...

the one which pissed me off was that asynchronous one...wtf?
lol
i knew i shouldve studied!!

 

[...]

wheres my gun, i'm gonna kill myself

 

[skip to my lou]

oh and another thing that caught me off guard


the systems flowchart
omfg....
lol
i had a go at it...hopefully i can get sOME marks!

 

[Agnes2810]

oh..i fkd that part! i forgot the symbols for output, process.. stuff like that.. r u talkin bout that question?

 

[skip to my lou]

ummm...the one about booking seats on the luxry coach company

 

[Huy]

Originally posted by skip to my lou
the one which pissed me off was that asynchronous one...wtf?
lol
i knew i shouldve studied!!

8 bits, 1 start, 1 stop.
I think it was A

I got the system flowchart out, it seems to make sense, with all the online displays, online inputs, processing of transaction, storing and retrieving them from databases (booking DB, customer DB, seating DB, etc).

 

[Roors]

OMG u people are hilarious! i think we had most of our trial ques's from cssa but we did it on mon....and i didnt no it was, but these all sound so familiar. I found it so much easier than last year though.....jus a bit of blabing is all it takes! Xcept the dataflow diagram....which i HATED but i liked the system flowchart! hehe ok maybe im weird!
And as for Huy...i dont no who u r...but i no ur a genius, so dont worry and PLZ ppl....the more u thin bak....the mre u'll think u stuffed up....and the more u'll stress b4 other exams....for NO reason!!

 

[tooheyz]

yeah roors does have a point

though i must say im FULL pissed off man...

bloody hell i almost missed out section 2 first 2 sections.. bloody hell.. thing was out teacher altered the paper by sticking a new sheet on the old and it made the paper bulkly and stuff... and those 2 questions were KINDA stuck together...

i finished 30 mins before and i though.. WHAT THE HELL?! and i flipped back and found i had totally missed the whole part!!!
so there i wass writing like crazy... it was the dfd question... AaRrGggHhh so hopefully i fudged the questions okay...

hmmm

as for the 9600bps questions, i got 0.4 seconds or something like that... becuase i didnt convert it man

i was reading all the posts and i noted that the questions u did, i didnt do man.. like the asynchronous questions?

what the hell? did i miss out on more questionS??!!!

 

[skip to my lou]

that was like question 19....multiple choice

 

[Huy]

Yeah, it was one of the last ones.

I was cracking up when I realised how stupid I was with the decision table. The one where you had:

OS <= 98
Budget < $1500
Monitor > 17"
Upgradable, etc

There was only ONE box with an "X" in it, marked for "purchase computer".

The answer was D,
Windows 2000, upgradable, 21", $1200 or thereabouts.

Tooheyz, the same thing happened to me with King Lear (Modules; Paper 2 for English). We had an ammended King Lear Question, although ours was on a separate sheet. I'd prefer everything to be in the one question booklet though, it makes it easier.

Chemistry was the biggest hassle though,
1. Multiple choice answer sheet
2. Periodic table and standard potentials sheet
3. Writing booklets
4. SPARE writing booklets
5. Question booklet

Then I had a calculator, pencil case, watch, ruler...the table is ONLY so wide! That's why I dump everything on the floor if I'm not using it

 

[JRasnier]

for the parity bit question...
i put 7 data bit, cause isnt the parity bit counted as the 8th bit?

 

[Huy]

According to error checking methods, no.

Parity checking is a method of checking for errors in data tranmission using an additional bit called a parity bit.

This bit is only used for the purpose of identifying whether the bits being moved have arrived successfully. When the data is represented using an 8-bit ASCII, then the ninth bit is used that holds a 0 or a 1.

See http://burks.brighton.ac.uk/burks/foldoc/64/86.htm
An extra bit added to a byte or word to reveal errors in storage (in RAM or disk) or transmission. Even (odd) parity means that the parity bit is set so that there are an even (odd) number of one bits in the word, including the parity bit.

A single parity bit can only reveal single bit errors since if an even number of bits are wrong then the parity bit will not change. Moreover, it is not possible to tell which bit is wrong, as it is with more sophisticated error detection and correction systems.

BUT, according to:
http://homepages.cwi.nl/~dik/english/codes/8tape.html#8even

Even parity, bit 8 is parity bit
Bit 8 is the "200" bit. It will not be shown in the following code displays. I know of two codes in this class:
i. Fieldata (Mobidic)
ii. ASCII (ISO, CCITT #5)

If it is represented as 7-bit ASCII, then the parity bit will be the 8th. If it is 8-bit ASCII, it will be the 9th bit (or additional bit ontop of the byte)

Was that Q in multiple choice?
If it was multiple choice, what were the other choices? (I can't remember, sorry, I've had an exam after IPT; chemistry so I've been dwelling on that for a while).

 

[JRasnier]

:mad1: :mad1:

 

[tigerboi]

argh ipt suck

 

[Huy]

Originally posted by tigerboi
argh ipt suck

No, you do!
j/k pete
IPT is cool.

Even though I stuffed up the trial,
I'll still do it ... damn it

 

[tigerboi]

lol ah think of the teacher "thats what i go to school for - busted".
well i think i skipped that 9400bps question. hAHhaha.
Aiming to beat allan aziz

 

[Huy]

Originally posted by tigerboi
lol ah think of the teacher "thats what i go to school for - busted".
well i think i skipped that 9400bps question. hAHhaha.
Aiming to beat allan aziz

LOL stop thinking about teachers that way!
(and if you are, dont tell me, because Im getting visuals now )

that 9400 bps question was pretty easy, but i guessed it. only to calculate it after the exam (much good that did)

allen's coming 4th or 5th?
you'll beat him, he's got nothing

 

[craz]

aside from dfd's. do i need to study context diagrams and be able to draw...topologies? and will someone explain to me the baud rate one... english tmr!!!!!!!