2.0 Computer System

 
2.1 System concept

 2.1.1 Overview of computer system

 What is Computer?

  an electronic device that accepts input process data and produces output

What is Computer System?

 a complete, working computer that includes operating system, software and hardware  which are  necessary to make the computer function

Components of Computer System

Hardware

Input devices

CPU

Output Devices

Storage Devices

Software

System Software

Application Software

Basic processes in computer

Input

Process

Output

Storage

Input-Process-Output (IPO) Model

2.1.2 Data representation

Data Representation

How does a computer represent data?
By using two unique binary digits 1 and 0 to represent the two states on and off.

Bit

• A binary digit (1 or 0)
• Represents an electrical state (on or off)
• Bit 1 represents On
• Bit 0 represents Off

Byte

• A group of 8 bits (ex:11110000)
• Represents a character such as a digit, a letter, a punctuation mark or any symbol in computer

Example :

00110100 represents 4

00110110 represents 6        

01000101 represents E