Lecture 9: Data Storage Devices Intro to IT

COSC1078 Introduction to Information Technology

Lecture 9

Data Storage DevicesJames Harland

james.harland@rmit.edu.au

Lecture 9: Video Intro to IT

Introduction

Who is this bloke?

Lecture 9: Data Storage Devices Intro to IT

Introduction

Lecture 9: Video Intro to IT

Overview

Questions?

WebLearn Test 1

Assignment 1

Binary Representation

Questions?

Lecture 9: Audio Intro to IT

Introduction to IT

1 Introduction

2 Images

3 Audio

4 Video WebLearnTest 1

5 Binary Representation Assignment 1

6 Data Storage

7 Machine Processing

8 Operating Systems WebLearn Test 1

9 Processes Assignment 2

10 Internet

11 Internet Security   WebLearn Test 3

12 Future of IT Assignment 3, Peer and Self Assessment

Lecture 9: Video SE Fundamentals

Questions?

How did you spend 6-8 hours on this course last week?

This week?

Lecture 9: Video Intro to IT

Assessment Process

Submit all assignments via Blackboard in the Learning Hub

Assignment 1 due 11.59pm Sunday 1st April

Assignment 2 due 11.59pm Sunday 6th May

Assignment 3 due 11.59pm Sunday 27th May

Late assignments attract a penalty of 10% per day late, up to a maximum of 50%

Lecture 9: Video Intro to IT

Assignment

Assignment will be in three parts

Overall task is to produce a video

Groups of up to 3

Assessed by final video and group blog

Part 1: images and audio (end of week 5)

Part2: hardware (end of week 9)

Part 3: reflection, research (end of week 12)

Lecture 9: Video Intro to IT

Assignment 1

Use GIMP (or a similar tool) to perform some manipulations on an image

Use Audacity to perform some manipulations on sound

Use a movie making tool to produce something like (and much better than!) ‘Lord of the Controllers 1 & 2’

Email me your group and its name so that I can set up a blog on the Learning Hub

Lecture 9: Data Storage Devices Intro to IT

Overview

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Lecture 9: Data Storage Devices Intro to IT

What do computers do? Compute!

Input/Output

Processing

Memory

Lecture 9: Data Storage Devices Intro to IT

History

… Babbage’s Difference Engine (1849) Babbage’s Analytical Engine (1837-1871, never

built) Turing’s Universal Machine (1936, mathematical

model) Turing digital Boolean-logic multiplier (1937) Colossus (1943, destroyed 1945) ENIAC (1946) Von Neumann architecture (c. 1945) EDVAC (1949) CSIRAC (1949)

Lecture 9: Data Storage Devices Intro to IT

Overview

“Thomas the Tank Engine”

Lecture 9: Data Storage Devices Intro to IT

Overview

Video

Audio

Text

Thumbnails

Lecture 9: Data Storage Devices Intro to IT

Memory via `Flip flops’

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Lecture 9: Data Storage Devices Intro to IT

Memory via `Flip flops’

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Lecture 9: Data Storage Devices Intro to IT

Memory via `Flip flops’

Can design other versions of flip-flops

Shows how circuits can be designed using AND, OR, NOT (NAND, NOR, XOR, …) in combinations (gates)

Hierarchy and abstraction

Shows how electric circuits can store values

Lecture 9: Data Storage Devices Intro to IT

Computer Memory

Cells of 8 bits each (one byte)

Most significant bit

Least significant bit

……

address

Lecture 9: Data Storage Devices Intro to IT

Random Access Memory (RAM)

Random access means any cell can be accessed at any time (and in any order)

Volatile – contents cleared when machine is switched off

Very fast compared to other forms of memory

DRAM: dynamic RAM (replenishes charges constantly)

SDRAM: synchronous DRAM – faster still

Often have small very fast caches and registers

Lecture 9: Data Storage Devices Intro to IT

Magnetic Disk

Thin spinning metal disk with magnetic coating

Each disk contains a number of circular tracks

Often several disks stacked on top of each other

Cylinders made up of tracks made up of sectors

Can have very large storage this way

Slow access time!

Lecture 9: Data Storage Devices Intro to IT

Magnetic Disk (Hard Disk)

Seek time: move heads from one track to anotherLatency time: half time for complete disk rotationAccess time: seek time + latency timeTransfer rate: rate data can be read from disk

`Typical’ Hard disk

Seek time: 2ms to 15msLatency time: 8ms to 20msTransfer rate: 0.5 GB per second

Sounds fast, but is actually quite slow …

Lecture 9: Data Storage Devices Intro to IT

Optical Disks (CDs, DVDs)

Laser readers rather than magnetic ones

Disks more error-tolerant than magnetic ones

Type Features Date Storage

CD “compact disk” 1984 800MB

DVD Multiple layers 1995 15GB

Blu-ray `blue laser’

(405 vs 650 nm)

2004 100GB

Lecture 9: Data Storage Devices Intro to IT

Flash Drives

Disks of all sorts are slow compared to other circuits

Flash drives ‘write’ small electronic circuits

Eventually decay after many changes of data

Suitable for slow-changing data, not main memory

Portable and much more resilient than disks

Lecture 9: Data Storage Devices Intro to IT

Older Storage Types

Magnetic tape

`Floppy’ disk (5.25’’ disk)

3.5’’ disk

Lecture 9: Data Storage Devices Intro to IT

Conclusion

Get Assignment done this week

Don’t forget to blog …

Keep reading! (book particularly)