Assembly Language:Simple, Short, And Straightforward Way Of Learning Assembly Programming

Assembly Language: Simple, Short, And Straightforward Way Of Learning Assembly Programming

Copyright 2016

Sherwyn Allibang

Edition License Notes

This book is authorized for your own personal use. This book may not be re-sold or offered away to other individuals. Much thanks to you for regarding the diligent work of the author.

Introduction

This book is intended for beginners who would like to learn the basics of Assembly Programming. This book uses Simple words, Short sentences and Straightforward paragraphs. The triple S way to learn Assembly Programming. The topics covered in this book includes a brief introduction to assembly, common arithmetic instructions, character and string input and display routines, flow controls including conditional and looping statements, stack, and procedures. This assembly language book is intended for complete beginners in assembly programming. However, it is assumed that the reader has prior or basic knowledge with other programming language. This book includes screenshots of step by step of how to code, compile, link and run assembly programs. This book is packed with working sample assembly programs and after reading this book, the reader would be able to develop assembly programs based particularly from problems given in computer science courses.

TO GOD BE THE GLORY!

The resources used in this book are:

1. Personal Computer running Windows 7 Operating System

2. Notepad ++ for editing codes available at https://notepad-plus-plus.org

3. DosBox emulator for DOS available at https://www.dosbox.com

4. TASM (Assembler) available at http://www.phatcode.net/downloads.php?id=280

Other Windows OS versions can also be used as long as it supports the above mentioned software. All links provided in this book are updated periodically.

NOTE: The sample programs in this book considers processors that support x86 assembly instructions.

Table of Contents

Acknowledgement

1. Chapter 1 - Introduction to Assembly Language

1.1 What is Assembly Language?

1.2 CPU REGISTERS

1.2.1 General Purpose Register

1.2.2 Segment Registers

1.2.3 Pointer Registers

1.2.4 Index Registers

1.2.5 Control Registers

1.3 Self-assessment questions

2. Chapter 2 - Our First Assembly Program

2.1 Assembly Program Structure

2.1.1 Fundamentals of Assembly Instructions

2.1.2 The MOV instruction in Assembly

2.1.3 The INT instruction in Assembly

2.1.4 Reserved words in assembly

2.2 Running our first Assembly program

2.2.1 How to install TASM?

2.2.2 Writing the Assembly Program Codes

2.2.3 Compiling (Assembling), Linking and Running the Program

2.3 Self-assessment questions

3. Chapter 3 - Input/Output Routines in Assembly Language

3.1 Simplified Segment Directives

3.2 Output Routines

3.3 Input Routines

4. Chapter 4 - Arithmetic Instructions in Assembly

4.1 Introduction to Arithmetic Instruction

4.2 The ADD Instruction (Addition)

4.3 The SUB Instruction (Subtraction)

4.4 The INC Instruction (Increment)

4.5 The DEC Instruction (Decrement)

4.6 The IMUL and MUL Instructions (Multiplication)

4.7 The IDIV and DIV Instructions (Division)

4.8 Handling numeric data

4.8.1 Algorithm in printing 2 digit number

4.8.2 Algorithm in printing 3 digit number

4.8.3 Algorithm in accepting 2 digit number

4.8.4 Algorithm in accepting 3 digit number

4.9 Self-assessment questions

5. Chapter 5 - Flow Control Instructions in Assembly

5.1 Conditional Control

5.1.1 Conditional Jumps

5.1.2 Unconditional Jump

5.2 Loop Control

5.2.1 Conditional Loop

5.2.2 Counter Controlled Loop

5.3 Self-assessment questions

6. Chapter 6 - Stack in Assembly

6.1 What is Stack?

6.1.1 PUSH operation

6.1.2 POP operation

6.2 Stack Simulation

6.3 Stack Oriented Program

6.4 Self-assessment questions

7. Chapter 7 - Procedures/Subroutines in Assembly

7.1 Defining a Procedure

7.2 Calling a Procedure

7.3 Procedure Oriented Program

7.4 Self-assessment questions

8. Chapter 8 - More assembly sample programs

8.1 OddEven Program

8.2 Legal Age Program

8.3 Alphabet Program

Answers to self-assessment questions

Disclaimer

Ending Notes

About the Author

List of sample programs:

1. Prints Char 'X'

2. prints 'x' 10times in red text over black BG

3. Prints 2 string variables

4. Clears screen and print a string

5. Sets color attribute on-screen

6. Sets cursor position on-screen

7. Accepts 1 char and prints it 5 times

8. Ask username and prints a welcome message

9. Prints sum of 2 numbers

10. Increments and decrements an entered number

11. Prints the quotient and remainder of entered numbers

12. Prints the sum and product of entered numbers

13. Prints the greatest number from entered numbers

14. Prints 9 to 1 using Loop

15. Prints 1 to 9 using Loop

16. Reverses string using stack

17. Prints number of characters in a string using procedure

18. Checks if entered number is odd or even

19. Checks if entered age is a legal age

20. Checks the vowels, consonants, lower and uppercases in a string

Acknowledgements

The author wishes to express his heartfelt gratitude to the Almighty God for His grace, wisdom, and guidance and for giving the author the determination to write this book. This book would not have been possible without the support and help of several individuals who in one way or another contributed and extended their valuable assistance in the preparation and completion of this material.

Dedication

The author dedicates this book to the ALMIGHTY GOD.

This book is also dedicated to Dennis Ritchie for giving the author the tools to program and to Bill Gates for giving the author the reasons to program.

Chapter 1 - Introduction to Assembly Language

This chapter presents a brief introduction in assembly and the needed concepts in starting assembly programming to solve computer science related problems.

What is Assembly Language?

Assembly language is a low-level and the most basic programming language available for any processor. In assembly, programmers works directly on operations implemented on the computer's processor. Due to the nature of assembly language, it lacks high-level programming convenience since its far from human language like other high-level programming languages does. With assembly language, instructions like JMP @X, MOV AH, 09D, JNZ, DEC and many others are the codes that programmers deals with. At first glance, this codes does not represent any English like words, so learning assembly language can be quite a challenge for beginners. These are mnemonic codes that represents instructions and unlike other programming languages, in assembly, a certain code can represent several instructions or meaning which makes it even more difficult.

Any computer has exactly two things on its foundation, a CPU and some Memory. These two makes computer programs run. The CPU reads the numbers one at a time, decodes them, and does what the numbers say, while the memory acts as the temporary storage location for the CPU. In assembly programming, programmers deal with instructions implemented directly on the CPU and memory.

CPU REGISTERS

CPU registers is a quickly accessible location available to a digital processor's central processing unit (CPU). Registers usually consist of a small amount of fast storage, although some registers have specific hardware functions, and may be read-only or write-only. In the CPU (32 bit) Registers, the 32 bit is the leftmost part of the register