Forum Moderators: mack
Section 4.1 introduces Unicode. Explain briefly – in two or three
sentences – how Unicode is used. Which character is
represented by 0111 0111 binary? Explain how you worked this
out. [7]
(c) Unicode is an example of a computing standard. Name one
other computing standard described in Unit 3, and say what it is
used for. [2]
(iii) (a) Name two common types of printer mentioned in Unit 3 and say
whether they provide analogue or digital output, giving a brief
reason in each case. [4]
(b) Imagine the following series of binary digits is a digital
representation stored in the memory of a computer.
1110 0000 1110 1010 0101 1110 …
(i) Does this sequence of bits have any meaning of its own?
Justify your answer. [2]
(ii) Describe what extra information would be needed before we
could regain the meaning of a series of binary digits such as
1110 0000 1110 11010 … via an output device.
You will lose one mark if your answer exceeds 100 words.
Please state at the end of your answer how many words you
Name two common types of printer mentioned in Unit 3 and say whether they provide analogue or digital output, giving a brief reason in each case.
What a strange test!
It seems it has "trick questions"
I wouldn't consider a printer to have "output" at all. Well, the printed page, but it's strange to think of that in terms of "analog" or "digital".
One MIGHT say that, say, a laser printer provides digital output, and a pen plotter analog.
But some laser printers actually lay down dots of varying density.
Is that then analog?
And pen plotters often have only a single pen pressure, and move in discrete steps. So, are they digital?
It's really a meaningless question.
The answer isn't on the test - it's that terminology that applies to electrical circuits is being misapplied.
i) No, unless all of the following can be determined, a sequence of bits in memory has no intrinsic meaning. It could be a representation of text to be displayed, other data, or stored program instructions. It could also be an unused area of memory still in the original state established when the computer was powered-up, which is, for most practical purposes, random.
ii) In order to determine the meaning of a sequence of bits in computer memory, it is necessary to know the machine's data word width and alignment (to determine the start of the character sequence -- That is, to be sure the first bits you're looking at represent the beginning of a character and that you're not starting halfway-through the digits for a character). You also need to know whether the machine uses a big-endian or little-endian data storage convention. Finally, you need to know the encoding standard, UTF-8, UTF-16, etc. You'd also need to know that you were looking at a section of computer memory where the data stored was, in fact, a representation of text to be displayed.
Hopefully, these points were covered in your text and lecture notes.
Jim
