【Mem oirs】 Week#4 Oct 3rd

Tutorial

Asusual, nothing special, we practised the codes we learnd about DrRacket last week, and gor prepare for the quiz today.

Lecture

Today's quiz was about the Animations in DrRacket, it was much more harder than the quizs we wrote before, we transferred statical to animations. In fact, the quiz was harder than I thought, maybe because I didn't practise enough? 

Today's lecture we learned about Binary deeper than last lecture. We had Multiplication, Negative numbers, fractions.

A common scheme, called IEEE floating point, uses 64 bits (binary digits): one for the sign, 11for the magnitute ( from 2^-1002 to 2^1023) and the remainder for an non-negative integer.

7 bits is enough to represent 128 values (2^7) .

Time goes so fast, next week we would have the Term Test One for this course, and we also had other term tests for other courses. Guess I have to work harder to face my first challenge, so nervous >_< ...

【Memoirs】 Week#3 Sep 26th

Tutorial

Today we got our first quiz result, surprisingly I did get 100% but I got one question wrong, if we got 4 out of 5 right we would get full mark. Nevermind it is still a 100 percentage, I should more attention about details next time. This tutorial was focus on quiz later. 

Lecture

We took our secong quiz today, it was not hard, that's it. Today we learned Representing information.

Two design ideas that computer have covered：
1. digital: Using discrete, sharply-changing, rather than analog, smoothly-changing states
2. Two states os the smallest, most easily designed

Boolean Logic

Binary:

The binary numeral system, or base 2-number system, represents numeric values using two symbols: 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2. Because of its straightforward implementation in digital electronic circuitry using logic gates, the binary system is used internally by almost all modern computers and computer-based devices such as mobile phones.

Binary Additoin:
0+0=0
0+1=1
1+0=1
1+1=10

Binary Subtraction:
0-0+0
1-0=1
1-1=0
10-1=1

Binary Multiplication:
0*0=0
1*0=0
0*1=0
1*1=1

Binary Division:
0/1=0
1/1=1


We now started learning Animations in DrRacket, more advanced than before. We had new codes, big-bang, on-tick, show-it, on-draw, stop-when, on-key etc.

【Memoirs】 Week#2 Sep 19th

Tutorial

We had our first quiz for this course, before the quiz I was so nervous about it. The first week we learn the basic codes/expression about DrRacket, for instance, flip, beside, scale, above, below, overlay etc. We kept practising the whole period and went to SF to took the first quiz.

Lecture

We came to SF and waited for the quiz. Be honest, a little bit nervous. The quiz started, when I got the quiz paper, I was so happy about it, because the quiz was so easy, and I pretty that I could get a 100% for quiz1.

After quiz, we started the lecture for this week. It's about Pre-modern computers.

IBM tabulator pins that go through card touch a mercuty, both of transmit eletricity. Information -> accumulator and rack pops open for card

Analog computers model world using smoothly-varying quantities, such as water. 

"programmable" (cards) but not electronic (relays) the Zuse Z1
In WWII era. lots of money to break codes and track projectiles.
In Germant Z1-> Z3 ward slow. noisy electromechanial realays-> only ran for a few hours
In US, fore-runner of ENIAC ( First computer in the world) had hard-wired programs

On Friday, we had our first project to due on Sep 21st. It's the Wikipedia assignment Part I,

it's about go register a wikiordia account and get to know how wikipedia works and the information about it, not hard actually.

【Memoirs】 Week#1 Sep 12th First Day of CSC104HF1

Lecture

This was the first day of class, we arrived at SF 1101,some of students did feel excited. Be honest, the major reason for me taking this course is someone did tell that this course is really really easy... 
Anyway, we came to the lecture, our handsome professor Danny Heap gave us some intrustions about this course and we went to labs in BA to set up our CDF account. 

We learned that computers and networks change society, like privacy, property, democracy, work, education etc. Make them better or worse.

Two tracks in this course:
1. History of computing technology, overview of modern computing OS, social issues.
2. Insight into computing mindset: problem-solving and programs.

Some advices about hwo to do well in this course:
1. Read the course information sheer as a two-way promise
2. Question, answer, record, synthrsize
3. Collaborate with respect

Early devices:

Clay tablets have benn used for at least 5,000 years.
Abacuses, or abaci have benn in use for nearly as long 
Hindu-Arabic     over 2,000 years ago
Antikythera mech anism

New software in this course  : DrRacket 
Basic expressions...

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