AQA COMP2 25th May 2012
Computer Science and ICT discussion, revision, exam and homework help.
-
- Reputation:
- Junior Member
- Posts: 48
Re: AQA COMP2 25th May 2012Flatbed Scanner:
1. Glass pane is illuminated by a bright light from beneath, item is placed face down on the pane with opaque cover on top.
2. The light source and light sensor move across the glass pane.
3. They pick up reflected light from anything on the pane.
4. The intensity of light reflected back from the entire area is read.
5. This reflected light is converted from optical form to electrical form, to produce the image/text in a digital format.
Is this all there is to include for principles of operation of a flatbed scanner or is there anything that I'm missing? thanks
-
- Reputation:
- Full Member
- Posts: 114
Re: AQA COMP2 25th May 2012Try this:(Original post by Ali_1)
Does anybody know the principle of operation of a USB flash drive?
http://en.wikibooks.org/wiki/A-level...SB_Flash_Drive -
- Reputation:
- Full Member
- Location: Yeovil, Somerset
- Posts: 114
Re: AQA COMP2 25th May 2012You've pretty much covered it, maybe mention how a Bitmap image is stored in the raster and how the top needs to be shut to prevent ambient light?(Original post by RoundNRound)
Flatbed Scanner:
1. Glass pane is illuminated by a bright light from beneath, item is placed face down on the pane with opaque cover on top.
2. The light source and light sensor move across the glass pane.
3. They pick up reflected light from anything on the pane.
4. The intensity of light reflected back from the entire area is read.
5. This reflected light is converted from optical form to electrical form, to produce the image/text in a digital format.
Is this all there is to include for principles of operation of a flatbed scanner or is there anything that I'm missing? thanks
-
- Reputation:
- Junior Member
- Posts: 48
Re: AQA COMP2 25th May 2012Thanks(Original post by A Wise Ninja)
You've pretty much covered it, maybe mention how a Bitmap image is stored in the raster and how the top needs to be shut to prevent ambient light? Anybody know the principles of operation for a digital still camera?
-
- Reputation:
- Full Member
- Posts: 114
Re: AQA COMP2 25th May 2012Take a look at this:(Original post by RoundNRound)
Thanks Anybody know the principles of operation for a digital still camera?
http://en.wikibooks.org/wiki/A-level.../Input_devices -
- Reputation:
- Full Member
- Posts: 114
Re: AQA COMP2 25th May 2012Have you looked at the section that says digital camera? It's highlighted in orange and says (with some pictures):(Original post by nathano14)
There's nothing useful on the page.
1 .Light is focused through the lens onto the image sensor at the back of the camera
2. The image sensor is made up of an array of Red, Green and Blue photosensors, called a Bayer filter. Each sensor will only record values for that particular colour.
3. The different colour arrays are combined to form an image
4. Once the RGB values have been captured, they can then be stored digitally using SD or compact flash cards. Save formats include JPEG or TIFF. -
- Reputation:
- New Member
- Posts: 10
Re: AQA COMP2 25th May 2012I think I noticed a mistake in that .pdf.(Original post by Lakhvir.Singh)
Found another resource on my computer that I used during revision. I never made this - I found it on the Internet!
"1+A = 1
0+A=0
0.A=A
1.A=A"
Should it not be 0+A=A and 0.A=0? :/ -
- Reputation:
- Exalted and Worshipped Member
- Location: Wirral
- Posts: 1,234
Re: AQA COMP2 25th May 2012Yes.(Original post by JohnHisk)
I think I noticed a mistake in that .pdf.
"1+A = 1
0+A=0
0.A=A
1.A=A"
Should it not be 0+A=A and 0.A=0? :/ -
- Reputation:
- Full Member
- Posts: 98
Re: AQA COMP2 25th May 2012did u make this up or get it from a source , let me know what it is(Original post by RoundNRound)
Flatbed Scanner:
1. Glass pane is illuminated by a bright light from beneath, item is placed face down on the pane with opaque cover on top.
2. The light source and light sensor move across the glass pane.
3. They pick up reflected light from anything on the pane.
4. The intensity of light reflected back from the entire area is read.
5. This reflected light is converted from optical form to electrical form, to produce the image/text in a digital format.
Is this all there is to include for principles of operation of a flatbed scanner or is there anything that I'm missing? thanks
-
- Reputation:
- Exalted and Worshipped Member
- Location: Wirral
- Posts: 1,234
Re: AQA COMP2 25th May 2012Cram time!
I'd play it safe and just do it in black and label, since they probably don't scan it in colour anyway...(Original post by Hullo)
Are we allowed to use colour for the webpage diagram or just label it? (As it might not scan properly or something)
-
- Reputation:
- Full Member
- Posts: 114
Re: AQA COMP2 25th May 2012Similar list is here:
http://en.wikibooks.org/wiki/A-level...vices#Scanners -
- Reputation:
- Full Member
- Posts: 86
Re: AQA COMP2 25th May 20121) A.B + A.notB(Original post by alphadawg)
Can someone help me to understand how to simplify these?
A.B + A.NOTB
A.(B+1)
B + B.NOTC
factorise to get A(B + notB)
B + notB gives you 1 so you have A(1)
which is A
2) A.(B+1)
B + 1 is 1, so you have A(1)
which is A
3) B + B.notC
factorise to get B(1 + not C)
1 + notC is 1, so you have B(1)
which is B -
- Reputation:
- Exalted and Worshipped Member
- Location: Wirral
- Posts: 1,234
Re: AQA COMP2 25th May 2012You can pretty much just treat them as normal maths...(Original post by alphadawg)
Can someone help me to understand how to simplify these?
A.B + A.NOTB
A.(B+1)
B + B.NOTC
For the first one...
A.B + A.NB
Take A out as a common factor...
A(B+NB)
B+NB = 1
A(1) = A
Second one...
B+1 = 1
A(1) = A
Third one...
B + B.NC
Take B out as a common factor...
B(1+NC)
1+NC = 1
B(1) = B -
- Reputation:
- Exalted and Worshipped Member
- Location: Wirral
- Posts: 1,234
Re: AQA COMP2 25th May 2012Beat me to it xD(Original post by fizzbizz)
X -
- Reputation:
- Full Member
- Posts: 86
Re: AQA COMP2 25th May 2012aha just about xD(Original post by iCiaran)
Beat me to it xD
do we need to know about how each of the application layer protocols work? like HTTP, FTP, Telnet etc :/
