 mov ah,1
int 21h
sub al,30h
mov num1,al

mov ah,1
int 21h
mov op ,al

mov ah,1
int 21h
mov num2,al

cmp op,'+'
je add1

cmp op,'_'
je sub1
 
cmp op,'*'
je mull
 
cmp op,'/'
je div1

lea dx,msg
mov ah,9
int 21h
end1 :
mov ah,4ch 
int 21h

add1 : 
mov ah,num1
add al,mun2
call print 
jmp end1 


sub1 : 
mov ah,num1
add al,mun2
call print 
jmp end1 

mul1 : 
mov ah,num1
add al,mun2
call print 
jmp end1 

div1 : 
mov ah,num1
add al,mun2
call print 
jmp end1 













num1 db ?
num2 db ?
op db ? 
msg db "error input$"

print  proc
  mov bl,10
  mov ah,00h
  div bl,
  mov dx,ax 
  add dx,3030h
  mov ah,2 
  int 21h
  mov dl,dh
  int 21h
  ret

created 1 year ago

Assembly Online Compiler

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.

About Assembly

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.

Syntax help

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.

Variables

There are various define directives to allocate space for variables for both initialized and uninitialized data.

1. To allocate storage space to Initialized data

Syntax

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

2. To allocate storage space to un-initialized data

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

Constants can be defined using

1. equ

To define numeric constants

CONSTANT_NAME EQU regular-exp or value

2. %assign

To define numeric constants.

%assign constant_name value

3. %define

To define numeric or string constants.

%define constant_name value

Loops

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.

Procedures

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