Introduction to Computers – Part 2 1

Computer Storage

Warning – Science Content!

Introduction to Computers – Part 2 2

An Analogue Device

Fully off (0)

Fully on (1)

Dimmer SwitchPartly on

Introduction to Computers – Part 2 3

A Digital Device

Fully off (0)

Fully on (1)

Light SwitchCan’t hold any intermediate value

Introduction to Computers – Part 2 4

The Binary Digit (Bit)

Value = 0 Value = 1

Introduction to Computers – Part 2 5

2 Bits = 4 Values

Switch 1 Switch 2 Value

OFF OFF 00 (0)

OFF ON 01 (1)

ON OFF 10 (2)

ON ON 11 (3)

Introduction to Computers – Part 2 6

8 Bits = 1 Byte = 256 Values

Introduction to Computers – Part 2 7

Bits and BytesBitByteKilobyte (KB)Megabyte (MB)Gigabyte (GB)Terabyte (TB)Petabyte (PB)Exabyte (EB)Zettabyte (ZB)1 Yottabyte (YB)

Introduction to Computers – Part 2 8

Computer Parts – The System Unit

Introduction to Computers – Part 2 9

Monitor/Screen

Introduction to Computers – Part 2 10

Keyboard

Introduction to Computers – Part 2 11

Mouse

Original mouse

Introduction to Computers – Part 2 12

Printer

Introduction to Computers – Part 2 13

Modem

Introduction to Computers – Part 2 14

Other Peripherals

Introduction to Computers – Part 2 15

Inside the Case

Introduction to Computers – Part 2 16

Motherboard

Introduction to Computers – Part 2 17

(Micro)Processor

Introduction to Computers – Part 2 18

Memory (RAM)

Introduction to Computers – Part 2 19

Great Moments in History - 2

"640KB [of memory] ought to be enough for anybody"

   Bill Gates, CEO of Microsoft, 1981

Introduction to Computers – Part 2 20

Hard Disk Storage (HDD)

Introduction to Computers – Part 2 21

Floppy Disk Drive

Introduction to Computers – Part 2 22

Optical Drive (CD/DVD)

Introduction to Computers – Part 2 23

USB Storage Devices

Introduction to Computers – Part 2 24

Processor speeds

• Computer speed is measured in billions of cycles per second or ‘GigaHertz’. (more is better).

• Modern computers can execute at about 3GHz

• That’s about 3,000,000,000 instructions every second!

Introduction to Computers – Part 2 25

Storage v MemoryStorage (HDD): Electromagnetic

Slow to access

Stores permanently - Contents remain when power is turned off

Memory (RAM):Electronic (semiconductor)Very fast access

Stores temporarily - Contents disappear when power is turned off!

Introduction to Computers – Part 2 26

The Operating System

Introduction to Computers – Part 2 27

The User Interface

Introduction to Computers – Part 2 28

Command Line User Interface (CLI)

xxcopysu "f:\Data" "G:\Data" /a /h /e /r /q /y /zy /ze /pb /yy /v /OF /OD3 /oa"F:\Data\Batch Files\XXCopy\backup.log"

Introduction to Computers – Part 2 29

Graphical User Interface (GUI)WINDOWS

Keep programs in separate boxes on the screen

ICONS represent programs or data

as picturesMENUS

present lists of available options

A POINTER Is used to select any object

on the screen

Introduction to Computers – Part 2 30

Microsoft Windows