Lecture 9: System Fundamentals Intro to IT COSC1078 Introduction to Information Technology Lecture 9 System Fundamentals James Harland [email protected].

Lecture 9: System Fundamentals Intro to IT

COSC1078 Introduction to Information Technology

Lecture 9

System FundamentalsJames Harland

[email protected]

Lecture 9: Computer Fundamentals

Intro to IT

Introduction to IT

1-4 Introduction, Images, Audio, Video

5 Computer Fundamentals Assignment 1, WebLearn Test 1

Tuesday March 30th, Wednesday March 31st

(no classes Thursday 1st April, Tuesday 6th April, Wednesday 7th April)

6 Computer Fundamentals

Tuesday April 13th, Wednesday April 14th

7 Computer Fundamentals /Review/Catch Up

8 Operating Systems WebLearn Test 1

9 Operating Systems Assignment 2

10 Internet

11 Internet Security   WebLearn Test 3

12 Future of IT Assignment 3, Peer and Self Assessment

Lecture 9: Computer Fundamentals

Intro to IT

Overview

Questions?

WebLearn Test 1

Assignment 1

Computer Fundamentals

Questions?

Lecture 9: Computer Fundamentals Intro to IT

Web Test 1

Now Week 5 (this week)

Some quizzes (practice tests) available now

Rest & test available later this week

Content will be on weeks 2-4

Images

Audio

Video

Lecture 9: Computer Fundamentals Intro to IT

Assignment 1

Due date is 9.00am on Monday 12th April (1st day of Week 6)

Can submit now if you wish …

Do submit something soon

Only PDFs for report

Lecture 9: Computer Fundamentals Intro to IT

Introduction

Lecture 9: Computer Fundamentals Intro to IT

Overview

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Lecture 2: Computer Fundamentals Intro to IT

What do computers do? Compute!

Input/Output

Processing

Memory

Lecture 2: Computer Fundamentals 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)

Lecture 1: Introduction Intro to IT

Overview

“Thomas the Tank Engine”

Lecture 1: Introduction Intro to IT

Overview

Video

Audio

Text

Thumbnails

Lecture 9: Computer Fundamentals Intro to IT

Memory via `Flip flops’

or

and

not1

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0 0 0

0

0

1

Lecture 9: Computer Fundamentals Intro to IT

Memory via `Flip flops’

or

and

not0

11

1 1 1

1

0

Lecture 9: Computer Fundamentals 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: Computer Fundamentals Intro to IT

Computer Memory

Cells of 8 bits each (one byte)

Most significant bit

Least significant bit

……

address

Lecture 9: Computer Fundamentals 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: Computer Fundamentals 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: Computer Fundamentals 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: Computer Fundamentals 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: Computer Fundamentals 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: Computer Fundamentals Intro to IT

Older Storage Types

Magnetic tape

`Floppy’ disk (5.25’’ disk)

3.5’’ disk

Lecture 9: Computer Fundamentals Intro to IT

Assignment 1

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

Address two issues in relation to this

Lab classes 2 and 3 based around GIMP

Main emphasis is on process, not result!

Is in the Learning Hub

SUBMIT VIA WEBLEARN

SUBMIT IT!NOW!!

Lecture 9: Computer Fundamentals Intro to IT

Conclusion

Web Test this week (week 5)

Do online quizzes later this week

Keep reading! (book particularly)