An Assembly Language Program to print Upper Case Letters from A to Z ( Simulation of Do-While Loop )

An Assembly Language Program to print Upper Case Letters from A to Z ( Simulation of Do-While Loop ) .

.MODEL SMALL

.STACK 100H

.DATA

PROMPT DB 'The Upper Case Letters from A to Z are : $'

.CODE

MAIN PROC

MOV AX, @DATA ; initialize DS

MOV DS, AX

LEA DX, PROMPT ; load and print PROMPT

MOV AH, 9

INT 21H

MOV CX, 26 ; initialize CX

MOV AH, 2 ; set output function

MOV DL, 41H ; set DL=A

@DO_WHILE_LOOP: ; loop label

INT 21H ; print character

INC DL ; increment DL to next ASCII character

DEC CX ; decrement CX

JNZ @DO_WHILE_LOOP ; jmp to label @DO_WHILE_LOOP

MOV AH, 4CH ; return control to DOS

INT 21H

MAIN ENDP

END MAIN