Lesson 1

STRUCTURE OF A CONVENTIONAL .EXE PROGRAM

stacksg segment para stack ‘stack’

;-------------------------------------------------------------------------------------------------------------------

stacksg ends

datasg segment para ‘data’

;-------------------------------------------------------------------------------------------------------------------

datasg ends

codesg segment para ‘code’

begin proc far

assume cs:codesg, ds:datasg, ss:stacksg

mov ax, datasg

mov ds, ax

--------------

--------------

mov ah, 4ch ;exit

int 21h

begin endp

codesg ends

end begin

STRUCTURE OF A CONVENTIONAL .COM PROGRAM

cseg segment para ‘code’

assume cs:cseg, ds:cseg, es:cseg, ss:cseg

org 100h

begin:

jmp begin

;--------------------------------------------------------------------------------------------------------------------

[DATA DEFINITION]

;--------------------------------------------------------------------------------------------------------------------

begin:

;--------------------------------------------------------------------------------------------------------------------

[MAIN PROGRAM]

;--------------------------------------------------------------------------------------------------------------------

INT 20H

CSEG ENDS

END START

LESSON 1

BASIC SCREEN OPERATION

I. OBJECTIVES

1. To practice assembling, linking and executing a program in assembly

2. To introduce the requirements in displaying information on the screen

II. INSTRUCTION / SERVICES

A. MOV Instruction

Format: MOV [DESTINATION], [SOURCE]

Data transfer instruction can be used in the following ways:

MOV [REGISTER], [REGISTER]

MOV [MEMORY LOCATION], [REGISTER]

MOV [REGISTER], [MEMORY LOCATION]

MOV [REGISTER], [IMMEDIATE DATA]

MOV [MEMORY LOCATION], [IMMEDIATE DATA]

B. LEA (Load Effective Address) Instruction

LEA [REGISTER], [MEMORY LOCATION]

C. Printing a...