Copyright © 2012 Pearson Education, Inc. Chapter 1 INTRODUCTION TO COMPUTING AND ENGINEERING PROBLEM SOLVING

Copyright © 2012 Pearson Education, Inc.

Chapter 1

INTRODUCTION

TO COMPUTING

AND ENGINEERING

PROBLEM SOLVING


Outline

Objectives

1.Historical Perspective

2.Recent Engineering Achievements

3.Computing Systems

4.Data Representation and Storage

5.An Engineering Problem-Solving Methodology


Objectives

Introduce computing and engineering problem solving, including:

• A brief history

• Recent engineering achievements

• A discussion of Numbering Systems

• A discussion of hardware and software

• A five-step problem-solving methodology

Historical Perspective


Charles Babbage, (1792-1871, above)

designed the Analytical Engine (left) to process

decimal numbers.

Augusta Ada Byron (1815-1852, below) wrote the first computer program.

Charles Babbage, Esq.1792-1871

• English mathematician.

• Designed the Analytical Engine in the early 1800s.

• Published “Of the Analytical Engine” in 1864.


Analytical Engine

• Designed to process base ten numbers.

• Consisted of four parts:– Storage unit– Processing unit– Input device– Output device


Analytical Engine

• 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


Augusta Ada Byron1815-1852

• 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.


Digital Computers

• 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.


Digital Computers

• ENIAC(Electronic Numerical Integrator And Calculator)

• Developed by research team lead by John Mauchly and J. Presper Eckert during the early 1940s.

• Weighed 30 tons.• Executed hundreds of instructions every second.


ENIAC vs. Intel Pentium 4


ENIAC executes hundreds of operations per second (30 tons)

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

Recent Engineering Achievements

Copyright © 2012 Pearson Education, Inc. Image credits: NASA/JPL/Malin Space Science Systems.


• Extraterrestrial Explorations– First manned lunar

landing (July 21, 1969)– Mars Global Surveyor,

Mars Reconnaissance Orbiter, and Mars Exploration Rovers

• Terrestrial Application Satellites

• Computer Axial Tomography (CAT) Scanners

• Computer simulations• Advanced composite

materials.• Speech understanding• Weather, climate, and

global change predictionCopyright © 2012 Pearson Education, Inc.


• Digital computers facilitate multidisciplinary engineering achievements that:– Improve our lives.– Expanded the

possibilities for our future.

• Changing engineering environment requires engineers with:– Communication skills.– Skills for working in

interdisciplinary teams.– An awareness of ethic

issues and environmental concerns.

– A global perspective.


Computing Systems


The von Neumann Computing Model

Computing Systems

• A computing system is a complete working system that includes:– Hardware– Software


Hardware

Hardware refers to the physical parts off the computing system that have mass (i.e. they can actually be touched):

– Computer– Display– Mouse– Printer– …


Hardware

Jon von Neumann computing model– Input device(s)– Output device(s)– Memory Unit– CPU (Central Processing

Unit) consisting of:• Control Unit• ALU (Arithmetic Logic Unit)


Software Interface to Computer Hardware


Software

Computer software refers to programs that reside and execute electronically on the hardware.

– Compilers– Translate source code

– Operating systems– Provide the HCI (Human Computer Interface)

– Application programs– Provide problem solutions


Building a Program

• Computers only understand machine language. High-level languages like C++ must be translated to machine language for execution.


Key Terms

• Source Program– printable/Readable Program file

• Object Program– nonprintable machine readable file

• Executable Program– nonprintable executable code


Errors in Programs

• 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.


Logic Errors

• Can be difficult to find.

• Debugging can be time consuming.– Better tools for find bugs

• It is important to carefully check the output of your programs for errors.– Even programs that appear to work correctly

may have bugs!


Debugging

• 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…


Data Representationand Storage

00110101001001001010101111101110

10101011111011100011010100100100

11000110110101011111001001001010

10101011111101001001000101110001

00100110111110101010001101010011

01001001001010101111101110001101

10100001101010010010111010011111Copyright © 2012 Pearson Education, Inc.

Data Representationand Storage

• Digital computers store information as a sequence of bits (binary digits).

• The value or state of a bit at any given time can be 0 or 1 (off or on).

• Data is stored as a sequence of bytes. – A byte is a sequence of 8 bits.


Memory Diagram

Address Space = 8

Word Size = 16


Address Sixteen Bit Word

000 0000101011011101

001 1010001011010100

010 1011010010100101

011 0101001101010101

010 0101000111001110

010 1100110000111010

110 0100011101001001

111 0101110001001000

Data Representation

• Right most bit is referred to as the least significant bit.

• Left most bit is referred to as the most significant bit.

• Value stored at address 000 is 00001010110111012 = 278110 But what does

it represent?


Numbering Systems

• Base ten number system• Ten decimal digits (0,1,2,3,4,5,6,7,8,9)• Each digit multiplies a power of ten

– Example:


24510 = 2*102 + 4*101 + 5*100

Numbering Systems• Base two (binary) number system

• Two binary digits (0,1)• Each digit multiplies a power of two

– Example:


101102 = 1*24 + 0*23 + 1*22 + 1*21 + 0*20

= 1*16 + 0*8 + 1*4 + 1*2 + 0*1 = 16 + 0 + 4 + 2 + 0 = 2210

Numbering Systems

• Base eight number system• Eight octal digits (0,1,2,3,4,5,6,7)• Each digit multiplies a power of eight

– Example:


2458 = 2*82 + 4*81 + 5*80

= 2*64 + 4*8 + 5*1 = 128 + 32 + 5 = 1658

Numbering Systems

• Base sixteen number system• Sixteen hex digits (0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F)• Each digit multiplies a power of sixteen

– Example:


2FB16 = 2*162 + F*161 + B*160

= 2*256 + F*16 + B*1 = 512 + 240 + 11 = 76310

Practice with Number Systems

1002 = ?8

37168 = ?2

1101001112 = ?10

3A1B16 = ?2


Practice with Number Systems

1002 = 48

37168 = 011 111 001 1102

1101001112 = 42310

3A1B16 = 0011 1010 0001 10112


Data Types

• Integer Data Type:– Often represented in 4 bytes (System

Dependent)– Left most bit is reserved for the sign of the

number– Remaining 31 bits represent the magnitude

of the number.


Data Types

• Representation of data affects the efficiency of arithmetic and logic operations.

• For efficiency, negative integers are often represented in their 2’s complement form.

• The 2’s complement of an integer is formed by negating all of the bits and adding one.


Two’s Complement

• Form the 2’s complement representation for the value -12710 assuming a word size of 8 bits for simplicity.12710 = 011111112

Negate bits: 10000000

Add 1: 10000001

• 2’s complement is 1000 00012


Two’s Complement

• Add 12710 to -12710


011111112 12710

+ 100000012 + -12710

= 000000002 = 010

Data Types

• Floating Point Data– Floating point types represent real numbers,

such as 1.25, that include a decimal point.– Digits to the right of the decimal point form the

fractional part of the number.– Digits to the left of the decimal point form the

integral part of the number.


Practice with Decimals

Convert 12.2510 to binary.


Practice with Decimals

Convert 12.2510 to binary.

First convert the integer part:

1210=11002

Then repeatedly multiply the fractional part by 2:

.25*2=0.5C0

.50*2=1.0C1

Therefore:

12.2510 =1100.012


Engineering Problem-Solving

Methodology


Five Step Problem-Solving

Methodology

1. State the problem clearly.

2. Describe the input and output.

3. Work a hand example.

4. Develop a solution.

5. Test your solution.Copyright © 2012 Pearson Education, Inc.

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Copyright © 2012 Pearson Education, Inc. Chapter 1 INTRODUCTION TO COMPUTING AND ENGINEERING PROBLEM SOLVING