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
AND gate
INPUT
OUTPUT
0
0
0
0
1
0
1
0
0
1
1
1
OR gate
INPUT
OUTPUT
0
0
0
0
1
1
1
0
1
1
1
1
NOT gate
INPUT
OUTPUT
0
1
1
0
2.Other Logic Gates
NAND gate
INPUT
OUTPUT
0
0
1
0
1
1
1
0
1
1
1
0
NOR gate
INPUT
OUTPUT
0
0
1
0
1
0
1
0
0
1
1
0
XOR gate
INPUT
OUTPUT
0
0
0
0
1
1
1
0
1
1
1
0
NXOR gate
INPUT
OUTPUT
0
0
1
0
1
0
1
0
0
1
1
1
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
!(x*y)=!x+!y
!(x+y)=!x*!y