Computing Concepts

1
Computing Concepts

• Week 1
• Lecture 1

2
Welcome to IT

• IT is an exciting world to work in
• You meet all kinds of interesting things

3
Its tough out there

• If computing were easy then anybody could do it
  and the money would be lousy

4
Its fun out there

• Challenging
• Dynamic
• much like herding cats
• full of very handsome people

5
Working together

• IT is a world where people must talk to one
  another to succeed
• Cannot do it in isolation
• On this course we need you to talk to
• us tutors
• when you get stuck (you know where we live)
• when you dont understand
• fellow students
• especially in group work

6
Official Learning Outcomes
Scary !!!
7
What it boils down to

• Knowing
• how the computer does its job
• how we can tell it what job to do
• how we can do it ethically
• how we can do it together

8
What we shall do today

• Computers as processors
• Based on Booklet Chapters 2 and 3

9
What is a computer ?

• Write down what you think a computer is
• Device that is told stuff
• Device that processes stuff
• Device that produces stuff
• Stuff ?
• words
• pictures
• sounds
• numbers
• mouse movements
• joystick movements

10
Computer as processor

• Supermarket checkout

Stuff coming in
Stuff getting processed
Stuff coming out
11
Human beings as processors

• Knitting

Stuff coming in
Stuff getting processed
Stuff coming out
12
Processors need instructions

• knit 2, purl 1

Instructions
13
Another example

• Baking a cake

Instructions
14
Computers as processors

• video game

Stuff coming in
Stuff getting processed
Stuff coming out
15
Video games
16
Aircraft controlled by computer
17
Airbus A320

• First fly-by-wire commercial airliner
  introduced 1988
• Cockpit cockpit image

18
Computers as processors

• Aircraft computer Clip of aircraft with computer
  control?

Stuff coming in
Stuff getting processed
Stuff coming out
19
Computers need instructions
20
Software - programs

• Whats the difference
• Software - literature
• Programs - books

21
Early computers Harvard Mark I

• 1944
• 55 feet long
• 8 feet high
• 5-tons
• Used by the US Navy for gunnery calculations
• In operation until 1959

22
Computer layout old style
Stuff coming out
Stuff coming in
23
Compare with a cook
Cakes
Ingredients
Spot the ingredients, recipe, cook and cakes
24
Computer layout old style

• Everything plugged into processor
• Processor became known as
• Central Processing Unit (CPU)

25
Computer layout new style
Stuff coming out
Stuff coming in
Bus (Bundle of wires)
26
A desktop computer system
Stuff getting processed
Stuff coming out
Stuff coming in
27
A desktop computer system with fancy words
Processor inside system box
Output device
Input device
28
Input devices

• mouse

• scanner

• keyboard

29
Input devices

• digital camera

• microphone

30
Input devices
31
Output devices

• printer

• speakers

32
Output devices
33
Storage devices

• This is where we store instructions

34
Storage device problems

• CPU can perform millions of instructions per
  second
• Storage device needs to keep up the supply of
  instructions
• Modern computers need to store thousands of
  programs

35
Storage device needs

• Must be
• fast
• able to store lots of programs
• This is expensive !!

36
Solution

• Use two kinds of storage device
• smaller, faster, expensive part
• larger, slower, cheaper part

Posh, easily reached, expensive bedside table for
current book
Cheap, slower, bookshelf for the rest of the
books
37
Solution

• Use two kinds of storage device
• smaller, faster, expensive part
• larger, slower, cheaper part

Main memory - very fast (purely electronic),
expensive. RAM
Secondary storage slower, (electro-mechanical),
cheaper. e.g. hard disc, CD, Floppy disc, Zip disc
38
Solution

• Normally keep the programs on the secondary
  storage
• Copy a program into main memory when we want the
  CPU to run it

39
What have we done today

• Computers as processors of data to provide
  information
• Computers use instructions to do their jobs
• Bus is used to connect components
• A range of devices is connected to the bus

40
Next time

• The devices in the computer system
• Concept of a computer program

41
Did you understand?