---
# System prepended metadata

title: ItC Week 2 - Number System & Data
tags: [Intro_to_Comp]

---

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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 %}
