1. Chapter 1: Introduction to Computers, Problem Solving, and Programming
Abstraction, and Design using C++ 6e
by Frank L. Friedman and Elliot B. Koffman

2. Algorithms
C++
Linux
Codewarrior

3. Early Computers Late 1930’s, John Atanasoff, Clifford Berry ENIAC 1946
University of Pennsylvania
J. Presper Eckert and John Mauchley
John von Neumann, stored-program concept

4. Categories of Computers
Supercomputers
Mainframe
Minicomputers
Microcomputers

5. Figure (a) Notebook Computer (HP Pavilion dv5©, Courtesy of Hewlett-Packard).   (b) Palmtop Computer (iPhone 3G©, Courtesy of Apple, Inc.) (c) Desktop Computer (iMac©, Courtesy of Apple, Inc.)

6. Computer Hardware CPU - central processing unit Main Memory
Where decisions are made, computations are performed, and input/output requests are delegated
Main Memory
Stores information being processed by the CPU
Secondary Memory (Mass Storage)
Stores data and programs

7. Computer Hardware Input devices Output devices Network connection
Allow people to supply information to computers
Output devices
Allow people to receive information from computers
Network connection
Modems
Ethernet interface

8. Figure 1.3 Components of a Computer

9. Memory Stores Types Composed of bits, which are combined into bytes
programs
operating system
applications
data
Types
RAM - volatile
ROM
Composed of bits, which are combined into bytes

10. Memory Cells Address Contents -27.2 1 2 354 3 4 0.005 5 6 -26 . . .1 2 3 4 5 6
. . .
999
-27.2
354
0.005
-26 H
RTV 001
. . . X
75.62

11. Figure 1.5 Relationship Between a Byte and a Bit

12. Secondary Memory Semi permanent data-storage capability
Magnetic
Hard disk
Floppy disk
Tape
Non-magnetic
CD or DVD
memory stick, flash drive
Secondary memory usually has much more storage capacity than main memory

13. Figure 1.6 Secondary Storage Media

14. CPU “Brains” of the computer
Arithmetic calculations are performed using the Arithmetic/Logical Unit or ALU
Control unit decodes and executes instructions
Registers hold information and instructions for CPU to process
Arithmetic operations are performed using binary number system

15. Figure The Intel Atom processor chip contains the full circuitry of a central processing unit in an integrated circuit whose small size and low power requirements make it suitable for use in mobile internet devices. (Intel Corporation Pressroom Photo Archives)

16. Input / Output Devices
Accessories that allow computer to perform specific tasks
Receiving information for processing
Return the results of processing
Common input and output devices
Keyboard Joystick Scanner
Printer Monitor Speaker

17. Computer Networks
Allows multiple computers to connect together to share resources and/or data
LAN - Local area network
Organizational
WAN - Wide area network
Internet
Requires additional hardware
modem
network interface

18. Figure 1.7 Local Area Network

19. Figure 1.8 A Wide Area Network with Satellite Relays of Microwave Signals

20. World Wide Web Introduced 1989 Developed by CERN Web browser
European Laboratory for Particle Physics
Web browser
GUI
Netscape IE

21. 1.3 Computer Software Operating system Other system software
utilities
programming language systems
Applications

22. Operating System E.g. Windows®, Unix® Controls
the interaction of system with the user
hardware interactions
Part is usually stored on ROM, rest on hard drive
This arrangement requires booting the system

23. Some OS Responsibilities
Communicating with the user; receiving user commands
Managing allocation of memory, processor time, file system, and other resources
Collecting input from keyboard, mouse, etc.
Conveying output to screen, printer, etc.
Writing data to secondary storage devices

24. Figure 1.9 Entering a UNIX Command for Directory Display

25. Figure 1.10 Accessing Secondary Storage Devices through Windows

26. Application Software Does the “real” work Common application software
Word processors
Desktop publishing programs
Spreadsheets
Presentation managers
Drawing programs

27. Programming Languages
Machine Language
Most fundamental language of the computer
Unique for each processor type
Binary 0s and 1s that specify what to do

28. Table 1.2 A Program in Machine and Assembly Language

29. High - Level Languages Resemble human language
C++, C, Pascal, FORTRAN, Ada
a = a + b;
More compact and human understandable than machine language
Must be translated into machine language

30. Object Oriented Programming
C++ derived from C by Bjarne Stroustrup
Popular because of reuse
Classes
Objects
Methods
Organized in a Hierarchy
Super Classes
Sub Classes

32. Object Oriented Design
Abstraction
Extract the relevant properties of an object while ignoring inessential details
Encapsulation
Breaking down an object into parts, hiding and protecting its essential information, and supplying an interface to modify the information in a controlled and useful manner

33. 1.4 Processing a High-Level Language Program
Set of programs used to develop software
A key component is a translator
Compiler
Examples
g++, Borland C++®, Microsoft Visual C++®
Other programs needed
Editor
Linker
Loader

34. Processing a Program Editor used to enter the program
Like minimal word processor
Creates source program file
Compiler translates the source program
Displays syntax errors
Creates (usually) temporary object code file
Linker/Loader to combine object file with other object files and execute program
Creates final executable program

35. Executing a Program CPU Special instructions used to
examines each program instruction in memory
sends out command signals required to carry out the instruction
Special instructions used to
input data into memory for the program to use
output data to display or printer (or other device)

36. Figure 1.11 Entering, Translating, and Running a High-Level Language Program

37. Figure 1.12 Flow of Information During Program Execution

38. 1.5 Software Development Method
Problem Analysis
Identify data objects
Determine Input / Output data
Constraints on the problem
Design
Decompose into smaller problems
Top-down design (divide and conquer)
Develop Algorithm (Desk check)
Algorithm refinement

39. Software Development Method
Implementation
Converting the algorithm into programming language
Testing
Verify the program meets requirements
System and Unit test
Maintenance
All programs undergo change over time

40. 1.6 Applying the Software Development Method
Case Study: Converting Miles to Kilometers
Problem  Your summer surveying job requires you to study some maps that give distances in kilometers and some that use miles. You and your coworkers prefer to deal in metric measurements. Write a program that performs the necessary conversion.

41. Case Study
Analysis  The first step in solving this problem is to determine what you are asked to do. You must convert from one system of measurement to another, but are you supposed to convert from kilometers to miles, or vice versa? The problem states that you prefer to deal in metric measurements, so you must convert distance measurements in miles to kilometers.

42. Data Requirements Problem Input miles distance in miles Problem Output
kms the distance in kilometers
Relevant Formula
1 mile = kilometers

43. Design Formulate the algorithm that solves the problem. Algorithm
1. Get the distance in miles.
2. Convert the distance to kilometers.
3. Display the distance in kilometers.
Algorithm Refinement
2.1 The distance in kilometers is the distance in miles
Desk check!

44. Listing 1.2 Miles to kilometers

45. Implementation #include <iostream> using namespace std;
int main( ) {
const float KM_PER_MILE = 1.609;
float miles, kms;
cout << “Enter the distance in miles: “;
cin >> miles;
kms = KM_PER_MILE * miles;
cout << “The distance in kilometers is “ << kms << endl;
return 0; }

46. Testing
Test with input data for which you can easily determine the expected results
E.g.
10 miles should convert to kilometers

47. 1.7 Professional Ethics for Computer Programmers
Privacy and Misuse of Data
Computer Hacking
Plagiarism and Software Piracy
Misuse of a Computer Resource