PowerPoint Presentation C3I Systems 2 Lecture 1

1

Basic Concepts about Computers and
Programs Lecture 2 Supporting Material Dr
Kathryn Merrick Thursday 5th March, 2009
2
(No Transcript)
3
Overview

• Computers and programs
• Computer memory
• Variables, values and types

4
What is a Computer?
5
Elements of a Computer System

• Input
• Processing
• Storage
• Output

6
Diagram 1 Elements of a computer system
7
Computer Memory
8
Memory

• Memory is organised in chunks
• Smallest chunk is a bit
• 0 or 1
• Then comes a byte
• Equal to 8 bits or 1 character
• Then a word
• Equal to 4 bytes (32 bits) or 8 bytes (on a 64
  bit machine)

a b 1 3 !
9
Computer Programs

• Computer programs are all about manipulating the
  contents of memory
• High level programming languages like MATLAB
  allow us to access variable memory chunks using
  human readable labels

10
Manipulating Memory Variables, Values and Types
11
Demo 1 Variables, values and types in MATLAB
12
Definition

• A variable is a chunk of memory that stores a
  value and has a name and type
• Exercise
• What are the names, types and values of these
  variables?
• name sally smith
• complete_lab_exercises 12
• assignment1_mark 0.85

13
Puzzle 1 Value swap
14
Summary

• After todays lecture you should be able to
• List the elements of a computer system
• Name and define the basic sized memory chunks
• Manipulate memory as variable values of different
  types