Introduction to Computer Systems

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1.What is a computer?
2.Logic Circuit Design

1.What is a computer?


A computer is a machine that can be programmed to accept raw data(input) and process it into useful information(output).
Computer System
  • Hardware
  • Computer(processor(CPU),Memory,I/O interface,etc.)
  • I/O devices(Keyboard,Mouse,Display,printer,Hard disk,etc.)
  • Software(Operating System,Compiler,Editor,etc.)
  • Binary Number
  • Instruction
  • Data
  • Unsigned Number
  • 2's Complement Number
  • Floating Point Number
  • etc.
  • 2.Logic Circuit Design


    0.Logic Circuit Design
  • Combinatinal Circuit
  • Sequential Circuit
  • 1.Basic Logic Gates
    1. AND gate
    2. INPUTOUTPUT
      000
      010
      100
      111
    3. OR gate
    4. INPUTOUTPUT
      000
      011
      101
      111
    5. NOT gate
    6. INPUTOUTPUT
      01
      10
    2.Other Logic Gates
    1. NAND gate
    2. INPUTOUTPUT
      001
      011
      101
      110
    3. NOR gate
    4. INPUTOUTPUT
      001
      010
      100
      110
    5. XOR gate
    6. INPUTOUTPUT
      000
      011
      101
      110
    7. NXOR gate
    8. INPUTOUTPUT
      001
      010
      100
      111
    3.Boolean Algebra
    x*0=0
    x*1=x
    x*!x=0
    x*x=x
    "*" means AND circuit.

    x+0=x
    x+1=1
    x+!x=1
    x+x=x
    "+" means OR circuit.

    4.De Morgan's Law
    1. !(x*y)=!x+!y
    2. !(x+y)=!x*!y