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# ItC Week 2 - Number System & Data

###### tags: `Intro_to_Comp`

- ## The Art of Managing Complexity

- Pyramid strcuture
- more advanced, more expensive components are less in number
- Abstract / Layering
- hiding unimportant details
- Discipline
- intentional restriction
- hardware example: analog &rArr; digital
- software example: single thread &rArr; multi processing
- Three -Y
- hierarchy
- divide system into modules & submodules
- modularity
- regularity

- ## Digitaliztion

- ## Number Systems

- Binary system
- Hexadecimal system
- makes binary numbers more readable
- Signed number
- sign/magnitude number
- 1 sign bit + N-1 magnitude bits
- sign bit is msb (most significant bit)
- issues with addition between positive and negative number
- overflow problem
- have 2 representation for 0
- 2's complement number
<!-- - $ A : {}$ -->
- $A = a_{n-1} (-2^{n-1}) + \sum_{i=0}^{n-2} a_i 2^i$
- starting from the smallest number
- instead of fliping numbers by 0
- msb still indicate sign
- flipping all bits then +1 equals negative
- Number extension

- ## Data Storage/Representations

- Text repersentation
- ASCII, extended ASCII, Unicode
- Words as high dimentional vectors
- Sound representation
- Image representation
- Data compression

- ## Logic gates

{%hackmd BJrTq20hE %}