Here's the simplest program in 8086 the hello world application. 

To Begin with , A simple "Hello World" program

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Program  : Hello World Program 
FileName : Helloworld.asm
I/P 	 : Nill
O/P 	 : Displays Hello World 
By       : Murugan AD 
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.model tiny  		  		; com program
.code			  		; code segment
org 100h		  		; code starts at offset 100h	

main proc near
  mov ah,09h		   		; function to display a string 	
  mov mov dx,offset message 		; offset ofMessage string terminating with $
  int 21h                  		; dos interrupt
  mov ah,4ch               		; function to terminate
  mov al,00
  int 21h  		   		; Dos Interrupt 
endp 
message db "Hello World $"		; Message to be displayed terminating with a $
end main

Generete Executable using Tasm / Tlink 
tasm helloworld.asm
tlink /t helloworld