CHAPTER 2 - THE PROCESSING UNIT

THE PROCESSING UNIT

Hardware

- Physical devices (Outside & Inside Computer)

Software

-Program install in the computer

-To perform certain activities

-Can be divided into Operating System and Application

Input

- A command for computer what to do (click, capture, touch, scan etc)

Output

- Display result

Basic Input / Output System

- Input  → Process → Output

Main Components in System Unit 

• Processor

• Memory

• Storage

• Expansion Slots & Adapter Cards

• Ports & Connectors

• Buses 

System Unit

Processor 

• Brain of computer

• Process instructions that come from

   memory or input

• Contain Central Unit & ALU

• Machine Cycle

• Clock Speed

Processor

Memory

•Use to keep records of information

•Types of Memory

-RAM (Random Access Memory)

       - Is volatile. Means it loses when the computer power is turn off

       - When you turn on computer certain operating system files load into RAM from storage devices.

-ROM (Read Only Memory)

-Memory chip storing permanent data and instructions. Its data cannot be modified.

-It is NON volatile. Which mean the content will not be lost if the power is turn off.

-Flash Memory

-Non volatile but can be erased and rewritten.

-Store data and programs on many mobile computer and devices – PDA, digital cameras, voice recorder and etc

-Cache Memory

-Improve processing time

-There are two types : Disk cache and Memory Cache

-It stores frequently used instructions and data

•Memory Access Time

- Amount of time that it takes the processor to read data, instructions and information from memory.

RAM

Expansion Slots & Adapter Cards 

• Expansion slot is a socket that hold

   adapter cards

• Adapter Cards is used to enhance the functions of a component / provide connections to peripheral

• Peripheral devices

Expansion slot & Adapter Card

Ports & Connector 

•Port Is a point at which peripheral attaches to or communicate with system unit. So that the peripheral can send and receives information from computer

•Example of ports:

USB, FireWire, MIDI, HDMI,

•Connector

Ports & Connector