Chapter 1
INTRODUCTION TO COMPUTERS
AND
PROGRAMMING PARADIGMS

 After you have read and studied this chapter, you should be able to
 State briefly a history of computers.
 Name and describe five major components of the computer.
 State the difference between the low-level and high-level programming languages.
 Describe how a Java program is processed
 Differentiate structured and object-oriented programming design methodologies

 In 1819, Joseph Jacquard, a
French weaver, discovered that the weaving instructions for his looms could be stored on cards with holes punched in them.

 Charles Babbage is credited as the father of computer.
Although never actually built, he proposed the computing machines called Difference
Engine and Analytical Engine that possessed the core characteristics of today’s computers.
 Ada Lovelace, who wrote demonstration programs for
Analytical Engine, is credited as the first programmer.

 The first modern computer was built by Atanasoff of Iowa State University in the late 1930s.
 An electromechanical computer
MARK I was built by Howard Aiken of
Harvard.
 Built in 1944
 Used punched cards to feed data into the machine
 52 feet long, weighed 50 tons, and had
750,000 parts
 The first completely electronic computer ENIAC I was built by
Mauchly and Eckert of the University of Pennsylvania.
 Built in 1946
 Electronic Numerical Integrator and
Calculator

 In 1956, the invention of the transistors resulted in smaller, faster, more reliable, and more energy-efficient computers
 This era also saw the emergence of the software development industry with the introduction of FORTRAN and
COBOL, two early programming languages
 In 1970, the microprocessor, an entire CPU on a single chip, was invented

 In 1977, Stephen Wozniak and Steven Jobs designed and built the first Apple computer in their garage
 In 1981, IBM introduced its personal computer (PC)
 Modern-day computers are very powerful, reliable, and easy to use
 Can accept spoken-word instructions and imitate human reasoning through artificial intelligence

Output
Devices
RAM
Communication
Devices
CPU
Storage
Devices
Input
Devices

For more information on Intel CPUs, click Intel Museum or Quick Reference Chart .

 programs written to perform specific tasks
 Two types of programs
 System programs
 Also known as operating system (OS)
 Essential programs that control the computer
 Example: boot up, memory allocator, clock, how characters are displayed, threading process, file manager, etc.
 Application programs
 Written using programming languages
 Perform a specific task
 Run by the OS
 Example: Word processors, Spreadsheets, Games

 Three levels of programming languages:
 Machine Languages
˗ Machine language instructions are binary coded and very low level.
 Assembly Languages
˗ Assembly language allows symbolic programming. Requires an assembler to translate assembly programs into machine programs.
 High-level Languages
˗ High-level language provides a very high conceptual model of computing. Requires a compiler to translate high-level programs into assembly programs.

Example:
Same task in 3 different languages

10110011 00011001
01111010 11010001 10010100
10011111 00011001
01011100 11010001 10010000
10111011 11010001 10010110

MV
MV
0, SUM
NUM, AC
ADD SUM, AC
STO SUM, TOT

X = ( Y + Z ) / 2

 Java is a high-level object-oriented language developed by Sun Microsystems.
 Two types of Java programs:
 An applet runs within a web browser
 An application is a complete stand-alone program that does not require a web browser.
 Java’s clean design and wide availability make it an ideal language for teaching the fundamentals of computer programming.

 Source program: written in a high-level language
 Compiler: a program that translates a program written in a high-level language into the equivalent machine language
 Loader: transfers the compiled code (bytecode) into main memory
 Interpreter: reads and translates each bytecode instruction into machine language and then executes it
 Java Virtual Machine (JVM): hypothetical computer developed to make Java programs machine independent

Processing a Java Program (continued)
Figure 1: Concept
Figure 2: Implementation

 Two basic approaches to programming design
 Structured design
 Object-oriented design
 INTRODUCTION TO OOP.pptx

1.
A problem is divided into smaller subproblems
2.
Each subproblem is solved
3.
The solutions of all subproblems are then combined to solve the problem

 In OOD, a program is a collection of interacting objects
 An object consists of data and operations
 Steps in OOD
1.
Identify objects
2.
Form the basis of the solution
3.
Determine how these objects interact