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An Introduction to Programming with C++, Third Edition
Overview
Lecture Notes
Overview
This overview reviews the basic components of a microcomputer system and the relationship between hardware
and software. In addition, a brief history of programming languages is presented taking the student from machine
language to current high-level languages.
Objectives
After completing the overview, the student will be able to:
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Describe the components of a microcomputer system
Explain the relationship between hardware and software
Explain the history of programming languages
Instructor Notes
An Introduction to a Microcomputer System
In the mid-1970s the first microcomputers, also called personal computers, appeared in the marketplace. In a very
short amount of time these devices have become a permanent part of how we do business today. For many tasks
that used to take a large amount of time manually, now take only seconds to accomplish with a microcomputer.
A microcomputer system is composed of both hardware and software. Hardware refers to the physical
components of the microcomputer system, while software refers to the programs that tell the hardware how to
perform a task.
An Overview of Hardware and Software
Hardware consists of such items as the system unit, peripheral devices, internal memory, and the CPU. The
system unit itself is the case that holds the main circuit boards, storage devices, and peripheral devices.
A peripheral device is attached to the system unit and is designed to extend the capabilities of the computer
system. A peripheral device also gives the user a means by which to communicate with the computer. The three
categories of peripheral devices are input, output, and auxiliary storage.
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An Introduction to Programming with C++, Third Edition
Overview
An input device allows the user to communicate with the computer by entering data into it. Examples of an input
device include a keyboard, mouse, and scanner. An output device allows the computer to communicate with the
user by displaying or printing information. Examples of output devices include a monitor and printer. An
auxiliary storage device allows you to store information permanently. Examples of an auxiliary storage device
include a floppy disk and hard disk.
Internal memory is an ordered sequence of memory cells contained on chips (integrated circuits residing on
silicon). The two basic types of internal memory are RAM and ROM. RAM (Random Access Memory) can read
from and write to memory cells while the computer has power, and is volatile (must have power to retain
contents). ROM (Read-Only Memory) can only read from memory cells while the computer has power, and is
non-volatile (does not require power to retain contents).
The CPU (Central Processing Unit) functions as the brain of the computer and is composed of the ALU and
control unit. The ALU (Arithmetic Logic Unit) performs the arithmetic calculations and logic operations for the
computer. The control unit directs the flow of information from one part of the computer to another. It is also
responsible for making sure that the computer correctly processes the program instructions and data is stored in
memory.
The two main categories of software are systems software and applications software. Systems software manages
the computer and its peripheral devices. Examples of systems software include the operating system (e.g.
Windows, DOS, Unix), device drivers, utilities, and programming languages. Applications software allows the
user to take a task that would otherwise be performed manually and carry out the same task with a computer.
Examples of applications software include word processors, spreadsheets, databases, entertainment software
(computer games), and educational software.
Quick Quiz
1.
__________ refers to the physical components of the microcomputer system.
Answer: Hardware
2.
A(n) __________ device is a device attached to the system unit, and extends the capabilities of the
computer system.
Answer: peripheral
3.
Floppy disk drives, hard disk drives, and CD-ROM drives are examples of __________ __________ devices.
Answer: auxiliary storage
4.
RAM stands for __________ __________ __________.
Answer: random access memory
5.
The two main categories of software are __________ software and __________ software.
Answer: systems, applications
A Brief History of Programming Languages
It is important to understand the relationship between three terms in programming: programs, programmers, and
programming. The directions that humans give to computers are called programs. The people who create these
directions are called programmers. And finally, the set of directions (programs) that programmers write are
written in a programming language. There are many different types of programming languages. This text will
discuss machine languages, assembly languages, high-level procedure-oriented languages, and high-level objectoriented languages.
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An Introduction to Programming with C++, Third Edition
Overview
Machine language is a language that uses bits/bytes to form instructions to communicate with a computer. Each
computer has its own instruction set (set of instructions it understands). Machine language uses binary, which is a
number system using 1’s and 0’s to represent data (base two). Each digit in binary is commonly called a bit
(binary digit) and eight bits form a byte. Each character entered into the computer will be represented by a unique
code consisting of 1’s and 0’s. ASCII (American Standard Code for Information Interchange) is a popular data
representation code using bits to represent numbers, letters, and symbols. (See the appendix for an ASCII
character table). Because of all the 1’s and 0’s, programming in machine language is very tedious and prone to
committing errors.
Assembly language is a language using mnemonics in place of 1’s and 0’s. Mnemonics are symbols used to
represent the actual machine language instructions. Since the only instructions that the computer understands are
machine language instructions, an assembler is required to convert the assembly language code to machine code
before being executed by the computer. Note that each assembly language instruction is translated into one
machine language instruction. It is easy to see that programming in assembly language is preferred to
programming in machine language; however programming in assembly language can also be very tedious.
High-level procedure-oriented languages allow the programmer to use instructions that more closely resemble the
English language. Still the only instructions that the computer can understand are machine language instructions,
therefore a compiler is required to convert the high-level code to machine code before being executed by the
computer. Unlike assembly language, each high-level language instruction may produce many machine code
instructions. The emphasis of high-level procedure-oriented languages is on accomplishing a task. The
programmer determines and controls the order in which the computer will process the instructions. The order of
execution of these instructions is extremely important and should be well designed. A design methodology called
top-down design is typically used with procedure-oriented programs. Top-down design begins with a general
statement describing the purpose of the program. This purpose is then broken down into smaller, more
manageable tasks, and eventually into the actual high-level procedure-oriented language instructions. Some
popular procedure-oriented languages include COBOL, BASIC, Pascal, and C. High-level procedure-oriented
languages make a vast improvement over machine and assembly languages.
High-level object-oriented languages view a problem solution as a set of interacting objects, where high-level
procedure-oriented languages view the problem solution as a set of ordered steps. Like procedure-oriented
languages, object-oriented languages require a compiler to convert the high-level instructions into machine code,
and each high-level object-oriented language instruction may produce many machine language code instructions.
Unlike procedure-oriented languages, with object-oriented languages a design methodology called OOD (ObjectOriented Design) is used. OOD, like top-down design, begins with a statement describing the purpose of the
program; however unlike top-down design the programmer then divides the program into one or more objects.
Objects in an object-oriented program may take on many forms, examples being menus, options buttons, and
command buttons. Objects may also take on real-life meanings, such as an employee, date, and a time card. Some
popular object-oriented languages include Visual Basic and C++. One main advantage of object-oriented
languages over procedure-oriented languages includes allowing a programmer to use familiar objects to solve a
problem. Then because these objects are viewed as independent units, they may be used in more than one
application with little or no modification.
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An Introduction to Programming with C++, Third Edition
Overview
Quick Quiz
1.
__________ write computer programs.
Answer: Programmers
2.
C++, Java, Visual Basic, and COBOL are examples of __________ __________.
Answer: programming languages
3.
Microcomputers typically use a coding scheme called ___________ for character representation.
Answer: ASCII
4.
A(n) __________ is used to convert assembly language instructions to machine language.
Answer: assembler
5.
A(n) __________ is used to convert high-level language instructions to machine language.
Answer: compiler
Discussion Topics/Classroom Activities
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Discuss with the class which operating systems and application software are available in your labs on your
campus. Also discuss why they were chosen.
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Discuss with the class which programming languages are taught in your curriculum and why they were
chosen.
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Show students examples of code from various programming languages and discuss with them the advantages
and disadvantages of each. If students have taken classes utilizing some of these languages make sure to let
them share their experiences.
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Have students write their first and last name in ASCII code. Discuss with them (even though it is apparent)
why we do not continue to program in machine language.
Projects to Assign
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Review questions at the end of the Overview
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Exercise #2 to better understand their own computer system
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Exercise #4 to show they understand the difference between the two types of language designs
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Exercise #7 to begin to lay a foundation for later assignments
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An Introduction to Programming with C++, Third Edition
Overview
Key Terms
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ALU (Arithmetic Logic Unit) - performs the arithmetic calculations and logic operations for the computer.
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Applications Software - acts as an interface between the user and the systems software, and allows the user
to perform specific tasks.
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ASCII (American Standard Code for Information Interchange) - 7 bit code used for representing characters.
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Assembler - used to convert Assembly Language instructions to Machine Language.
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Assembly Language - a language using mnemonics in place of 1's and 0's, as with Machine Language.
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Auxiliary Storage Device - allow you to store information permanently (examples include a floppy disk and
a hard disk).
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Compiler - a software program that coverts High-Level Procedure-Oriented and Object-Oriented program
instructions into Machine Language.
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Control Unit - directs the flow of information from one part of the computer to another, and is responsible for
making sure that the computer correctly processes the program instructions stored in memory.

CPU (Central Processing Unit) - functions as the brains of the computer and is composed of the ALU and
Control Unit.

High-Level Procedure-Oriented Language - allows the programmer to use instructions that more closely
resemble the English language.

Input Device - allow the user to communicate with the computer by entering data into it (examples include a
keyboard, mouse, and scanner).

Internal Memory - ordered sequence of memory cells contained on chips.

Machine Language - a language that uses bits/bytes to form instructions to communicate with a computer
system.

Mnemonics - symbols used to represent actual Machine Language instructions.
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Non-Volatile - retains contents with loss of power (opposite of volatile).
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Object-Oriented Language - a language that views a problem solution as a set of interacting objects.
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Operating System - a collection of software program that is the link between the computer and the user
(examples include Windows, DOS, OS/2, and UNIX).
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Output Device - allows the computer to communicate with the user by displaying or printing information
(examples include a monitor and a printer).

Peripheral Devices - attached to the system unit, designed to extend the capabilities of the computer system,
and gives the user a means to communicate with the computer

RAM - (Random Access Memory) - can read from or write to memory cells while the computer has power,
and is volatile.
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An Introduction to Programming with C++, Third Edition
Overview
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ROM - (Read-Only Memory) - can read from memory cells while the computer has power, and is nonvolatile.
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System Unit - case that holds the main circuit boards, storage devices, and peripheral devices.
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