Lecture 1 - intro to computing.pdf

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©1992-2012 by Pearson Education, Inc. & John Wiley & SonsReferences: Engineering Problem Solving with C++ (Etter et al.), C++ How to Program (Deitel et al.), C++ for Everyone (Horstmann)

ENGR 1200U Introduction to Programming

Lecture 1 Course Overview

Introduction to Computing

Dr. Eyhab Al-Masri

ENGR 1200UWinter 2013 - UOIT

Textbook◦ Engineering Problem Solving with C++ Authors: M. Etter, Jeanine A. Ingber Publisher: Prentice Hall 3rd Edition, 2012 ISBN: 0132492652

Evaluation Method◦ Assignments 20%◦ Quizzes 10%◦ Midterm Exam (Wed Feb 27) 20%◦ Final Exam (TBD) 50%

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Introduce computing and engineering problem solving, including:

◦ A brief history of computers◦ To learn about the architecture of computers◦ To learn about machine languages and higher-level

programming languages◦ To compile and run your first C++ program◦ To recognize compile-time and run-time errors


Yes, ALL that is ONE computer!(except the people)

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Early 1800s, Charles Babbage (above)

designed the Analytical Engine (left) to process

decimal numbers

In 1842, Augusta Ada Byron (below) wrote the first computer program.


English mathematician Designed the Analytical Engine in the early

1800s◦ Performs only simple mathematical operations

Used for general purposes Read instructions from punched cards and carried them

out Punch different programs on input cards

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Designed to process base ten numbers

Consisted of four parts:◦ Storage unit (memory)◦ Processing unit (computation unit)◦ Input device (punched card reader)◦ Output device (punched and printed output)


Luigi F. Menabrea, French engineer and mathematician, described Babbage’s vision of a machine capable of solving any problem using:

◦ Inputs◦ Outputs◦ Programs written on punch cards

Published a paper “Sketch of the Analytical Engine Invented by Charges Babbage, Esq”

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Wrote the English translation of Menabrea’s Sketch of the Analytical Engine

Envisioned the multidisciplinary potential of the Analytical Engine

Wrote detailed instructions for performing numerical computations using the Analytical Engine


ABC (Atanasoff Berry Computer) Developed at Iowa State University between 1939 and 1942

by John Atanasoff and Clifford Berry

Weighed 700 pounds

Executed one instruction every 15 seconds

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ENIAC (Electronic Numerical Integrator And Calculator)◦ Developed by research team lead by John Mauchly

and J. Presper Eckert during the early 1940s

◦ Consisted of 18,000 vacuum tubes and 1500 relays

◦ Weight: 30 tons, 6000 switches, many jumper cables

◦ Consumed: 140 kilowatts of power

◦ Executed hundreds of instructions every second


ENIAC executes hundreds of operations per second (30 tons)

Today’s processors execute trillions of operations per second and weigh ounces.

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Advances of the digital computer has facilitated many significant engineering achievements over the past five decades

◦ Achievements illustrate how engineering has improved our lives and expanded possibilities of the future


Some of the major achievements◦ Exploration of space 1996: Mars Global Surveyor: a spacecraft developed by

NASA for collecting scientific data while in orbit

◦ Application Satellites Used to provide weather information, relay communication

signals, maps, and environmental updates Example: GPS

◦ Computer Simulations Allow for experimentation that may not be possible (due to

size, speed, dangers to health and safety, etc…)

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You have probably used a computer for study, work or fun

Many people use computers for everyday tasks such as electronic banking or writing a term paper

Computers are good for such tasks

C++ is a powerful computer programming language that’s appropriate for technically oriented people to use in building substantial information systems


In use today are more than a billion general-purpose computers and billions more cell phones, smartphones and handheld devices (such as tablet computers)

The number of mobile Internet users will reach approximately 134 million by 2013

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By 2014, the smartphone applications market is expected to exceed $40 billion, which is creating significant opportunities for programming mobile applications

Studies have projected smartphone sales to surpass personal computer sales in 2011 and tablet sales to account for over 20% of all personal computer sales by 2015


Computing in Industry and Research

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Computers can carry out a wide range of tasks because they execute different programs, each of which directs the computer to work on a specific task

The computer itself is a machine that stores data (numbers, words, pictures), interacts with devices (the monitor, the sound system, the printer), and executes programs


A computer program tells a computer, in minute detail, the sequence of steps that are needed to fulfill a task

HardwareThe physical computer and peripheral devices

are collectively called the hardware

SoftwareThe programs the computer executes are

called the software

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Programming

is the act of designing andimplementing computer programs

The user is the human using a program that a programmer wrote


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The von Neumann Computing Model

In 1946, John von Neumann proposed a computing model that is still used today in the design of most digital computers


The CPU (central processing unit)◦ heart of the computer◦ executes one operation at a time◦ performs program control and data processing

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The CPU◦ carries out arithmetic operations such as addition,

subtraction, multiplication, and division

◦ fetches data from external memory or devices and stores data back

All data must travel through the CPU whenever it is moved from one location to another


Arithmetic Logic Unit

◦ Performs arithmetic and logic operations

◦ ALU is a fundamental block for CPU of a computer

◦ All CPUs and Graphical Processing Units (GPUs) all have complex ALUs

Accumulator: used for temporary storage of values and results

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The computer stores data and programs in memory◦ Primary memory - memory chips Random access memory (RAM) (read-write memory) Read-only memory (ROM)

◦ Secondary storage devices Disk drives DVDs


Controls the transfer and processing of data

Retrieves and interprets instructions stored in memory

Accepts data from an input device (i.e. keyboard or mouse),

Sends data to a specified output device (i.e. printer or display)

Stores data in the memory unit

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The computer transmits information (called output) to the user through a display screen, speakers, and printers

The user can enter information (called input) for the computer by using a keyboard or a pointing device such as a mouse


Computer software contains the instructions or commands that we want the computer to perform

There are several categories of software (right)

1. Operating Systems2. Application Software3. Computer Languages

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Operating Systems typically comes with the computer hardware when purchased

OS provides an interface between the user and the hardware (allows user to select and execute software)

OS contain a group of programs called utilities that allow the user to perform functions such as printing files, copying files, etc…

OS simplify the interface with the OS by using icons and menus (Examples: Windows)


Common Applications◦ Purpose: Perform common operations◦ Examples: word processors, text editors, spreadsheet

Database management software◦ Purpose: Efficiently store and retrieve larges amounts of data◦ Examples: MySQL, Oracle, Microsoft SQL

Computer Aided Design (CAD)◦ Purpose: Define objects and manipulate them graphically◦ Examples: AutoCAD, Architectural Desktop, Civil 3D which

Mathematical Computation Software◦ Purpose: Powerful mathematical commands & generate graphs◦ Examples: Matlab, Mathematica, Maple

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Computer languages can be described in terms of levels

Programmers write instructions in various programming languages, some directly understandable by computers and others requiring intermediate translation steps.

These may be divided into three general types:◦ Machine languages◦ Assembly languages◦ High-level languages


Low-level languages (or machine languages)◦ Most primitive and are tied closely to the design of the

hardware (instructions are encoded)

◦ Generally consist of strings of numbers (ultimately reduced to 1s and 0s)

◦ Machine dependent—a particular machine language can be used on only one type of computer

◦ Machine language differs from one machine to another (i.e. Sun versus HP computer)

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Assembly language◦ Instructions are written in symbolic statements instead

of binary

◦ Also unique to a specific computer design

◦ Usually have limited set of statements Makes task of writing programs very tedious

◦ Translator programs called assemblers convert assembly-language programs to machine language


High-level language◦ Have English-like commands and instructions

◦ Examples: C, C++, Java, VB.NET, C#, etc…

◦ Independent of the processor type and hardware

◦ Writing programs in high-level language is much easier that machine or assembly

◦ Contain large number of commands and an extensive set of syntax (or grammar) rules

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Computers only understand machine language

High-level languages like C++ must be translated to machine language for execution

◦ Compiler A special computer program that translates higher-level

programs into machine instructions for a particular processor


Source Program◦ printable/Readable Program file

Object Program◦ nonprintable machine readable file

Executable Program◦ nonprintable executable code

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Syntax/Parse Errors◦ Mistakes with the language◦ Always reported by the compiler

Linking Errors◦ Missing pieces prevent the final assembly of an

executable program

Run-time Errors◦ Occur when program is executing◦ May or may not be reported


Can be difficult to find

Debugging can be time consuming◦ Better tools for finding bugs

It is important to carefully check the output of your programs for errors

◦ Even programs that appear to work correctly may have bugs!

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Process of eliminating logic errors(i.e. bugs) from programs

User-friendly programming environments such as Microsoft Visual C++ integrate the compiler with ◦ text processors and code editors◦ special tools to help find bugs in programs (debugger)◦ testing tools◦ and much more…


You will need to know how to log in (if needed), and, how to start your C++ development environment

An IDE (integrated development environment) is where you will most likely work

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You will become a typist because you will use an editor to type your C++ programs into the IDE

Your program is called a source program (file)


You will need to learn how to compile and run your program in the IDE

There’s a lot going on behind the

scenes in the IDE that you don’t normally see

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The compiler translates C++ programs into machine code

The linker combines machine code with library code into an executable program


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You will need to know your computer’s file system:files, folders, and extensions

C++ program files typically have the extension:.cpp (or .cc or .cxx or even .C)

You should be organized by creating folders for organizingyour files


You can use any of the following IDEs:

Microsoft Visual Studio (C++)

NetBeans

Eclipse

Dev C++

CodeLite

Lecture 1 - intro to computing.pdf

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