; "hello, world!" step-by-step char-by-char way... 
; this is very similar to what int 21h/9h does behind your eyes. 
; instead of $, the string in this example is zero terminated 
; (the Microsoft Corporation has selected dollar to terminate the strings for MS-DOS operating system) 

name "hello"

org     100h   ; compiler directive to make tiny com file. 

; execution starts here, jump over the data string: 
jmp     start

; data string: 
msg db 'Hello, world!', 0

start:

; set the index register: 
        mov     si, 0

next_char:

; get current character: 
        mov     al, msg[si]
; is it zero? 
; if so stop printing: 
        cmp     al, 0
        je      stop

; print character in teletype mode: 
        mov     ah, 0eh
        int     10h

; update index register by 1: 
        inc     si

; go back to print another char: 
        jmp     next_char


stop:  mov ah, 0  ; wait for any key press. 
       int 16h

; exit here and return control to operating system... 
        ret

end     ; to stop compiler. 

this text is not compiled and is not checked for errors,
because it is after the end directive; 
however, syntax highlight still works here.