print macro msg
lea dx,msg
mov ah,09h
int 21h
endm
read macro n,j1,j2
mov cx,0ah
j1:mov ah,01h
int 21h
cmp al,0dh
je j2
sub al,30h
mov bl,al
mov ax,n
mul cx
xor bh,bh
add ax,bx
mov n,ax
jmp j1
j2 :nop
endm
.model small
.stack 100h
.data
msg1 db 10,13,'Enter the 1st number: $'
msg2 db 10,13,'Enter the 2nd number: $'
msg3 db 10,13,'The LCM= $'
data1 dw 0
data2 dw 0
dat1 dw 0
dat2 dw 0
.code
main proc
mov ax,@data
mov ds,ax
print msg1
;reading 1st multidigit number
read data1,jump1,jump2
print msg2
;reading 2nd multidigit number
read data2,jump3,jump4
;copy the data1 and data2 to dat1& dat2
mov bx,data1
mov dat1,bx
mov cx,data2
mov dat2,cx
;Algorithm for finding lcm
;if(dat1=dat2) then finish, lcm=dat1 or dat2
;elseif(dat1<dat2) then dat1=dat1+data1
;else dat2=dat2+data2
;repeat
loop1:mov ax,dat1
cmp ax,dat2
je jump5
jc jump6
mov ax,dat2
add ax,cx
mov dat2,ax
jmp loop1
jump6:mov ax,dat1
add ax,bx
mov dat1,ax
jmp loop1
;printing LCM
jump5:mov bx,0ah
xor cx,cx
;push into stack
p1:xor dx,dx
div bx
push dx
inc cx
cmp ax,00h
jne p1
print msg3
;pop from stack
display:pop dx
add dl,30h
mov ah,02h
int 21h
loop display
mov ah,4ch
int 21h
main endp
end Write, Run & Share Assembly code online using OneCompiler's Assembly online compiler for free. It's one of the robust, feature-rich online compilers for Assembly language. Getting started with the OneCompiler's Assembly compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as Assembly and start coding.
Assembly language(asm) is a low-level programming language, where the language instructions will be more similar to machine code instructions.
Every assembler may have it's own assembly language designed for a specific computers or an operating system.
Assembly language requires less execution time and memory. It is more helful for direct hardware manipulation, real-time critical applications. It is used in device drivers, low-level embedded systems etc.
Assembly language usually consists of three sections,
Data section
To initialize variables and constants, buffer size these values doesn't change at runtime.
bss section
To declare variables
text section
_start specifies the starting of this section where the actually code is written.
There are various define directives to allocate space for variables for both initialized and uninitialized data.
variable-name define-directive initial-value
| Define Directive | Description | Allocated Space |
|---|---|---|
| DB | Define Byte | 1 byte |
| DW | Define Word | 2 bytes |
| DD | Define Doubleword | 4 bytes |
| DQ | Define Quadword | 8 bytes |
| DT | Define Ten Bytes | 10 bytes |
| Define Directive | Description |
|---|---|
| RESB | Reserve a Byte |
| RESW | Reserve a Word |
| RESD | Reserve a Doubleword |
| RESQ | Reserve a Quadword |
| REST | Reserve a Ten Bytes |
Constants can be defined using
CONSTANT_NAME EQU regular-exp or value
%assign constant_name value
%define constant_name value
Loops are used to iterate a set of statements for a specific number of times.
mov ECX,n
L1:
;<loop body>
loop L1
where n specifies the no of times loops should iterate.
Procedure is a sub-routine which contains set of statements. Usually procedures are written when multiple calls are required to same set of statements which increases re-usuability and modularity.
procedure_name:
;procedure body
ret