This week we’ve learnt a lot: what is a binary number system, how does a computer work, as well as ASCII and unicode. Things get more complicated and more innteresting, and we also did some activities to better illustrate these abstract concepts about computers.
Binary number system
First, we learnt binary number system. Computer converts data, which is stored and transmitted as a series of zeros and ones, into information.
I wondered why we only let computers using zeros and ones, for the binary number system need more space than decimalism. By searching on internet, I understood that binary system is easy to achive, since we can let “close the circuit” to be zero and “break the circuit” to be one. What’s more, it is easy to calculate.
So how to convert decimal to binary? First, split the number into the sum of the power of 2. For example, 7=2^2+2^1+2^0. Second, find the length of the binary number. The length is the biggest power plus one. In this case, it’s 2+1=3. Finally, fill the space: fill one on each power+1’s space (counting from right) and then fill the remain space zero. So 7=111. If we want to convert binary to decimal, just plus each 2^(place-1) for every place that contains one. For instance, 111=2^0+2^1+2^2+7.
That’s interesting! We also had an activity that five volunteers respectively represented 1, 2, 4, 8, and 16. We counted from 1 to 31 by combinding these numbers. I found the idea of “combinding/rearranging things we already have to form new things/to convey information” really interesting and useful. In our life, for instance, we use English which have only 26 letters. It is so helpful, just because we arrange letters in different ways! We also did a worksheet to practice our skills.
How does a computer work
In order to understand how does a computer work, we fist looked at some important terms: CPU, CU, ALU, Register, and Bus. CPU, the central processing unit, is like the brain of a computer. It is where computers execute instructions form memory. Basically there are four parts in the CPU: CU, ALU, Register and Bus. As for CU, control unit, it makes decisions and sends signals to other parts of the computer. Arithmetic Logic Unit (ALU) is the place to do calculations and it can also deals with logic. Register can store information temporarily. Bus‘s function is to carry information to other parts of the CPU.
Then we watched a cute video in which we all became “electrons” and had a wonderful tour inside of the computer. We surprisingly known that there are so many steps between a click and the final display. Sometimes we ignore and despise little things like these and consider them as “very easy stuff”, but only if we do it oulselves we can find out the truth.
So here is my understanding of how does a computer work: When the computer receives instruction (input) from the user, the CPU begins to execute these information at once. CU get information from memory and send them to ALU and register through bus. Bus also carries infromation from CU to display. Finally we can get our output shown in display.
We were also divided into groups to experience this, and our group got a strange pattern (it is supposed to be a heart). The error may occur in any of us: CU(me), ALU(Hania), display(Catherine), and I realized in a team we need everybody perform well, otherwise we can’t get a good result.
ASCII and UNICODE
ASCII, American Standard Code for Information Interchange, is a standard that assigns letters, numbers,and other characters in the 256 slots available in the 8-bit code. For example, lowercase i would be represented in the ASCII encoding by binary 01101001.
Unicode is a standard for the consistent encoding, representation, and handling of text expressed in most of the world’s writing systems.
There are many differences between them:
• Unicode is an expedition of Unicode Consortium to encode every possible languages but ASCII only used for frequent American English encoding. For example, ASCII does not use symbol of pound or umlaut.
• Unicode require more space than ASCII.
• ASCII only supports 256 characters while Unicode supports much more characters.
In conclusion, this week we had a glimpse at the inside of our computers: we learnt their language (binary system), how they work and some smart ways letting they work (ASCII and unicode). I had a feeling that some of the students really known a lot about computers and I’m very new to it. Nevermind, I’m sure I will get more fimiliar with my friend–Mr. Computer!
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