boot.s

        org 7C00h
        jmp short Start
 
Hello:  db "Hello World!"
Len: 

Start:
        xor ax, ax
        mov es, ax
        mov bp, Hello
        mov cx, Len-Hello

        mov ax,0x1301	;write a string
	mov bx,0x001F	;page 0, white on blue
	mov dx,0x0101	;first column, first row

	int 0x10
 
 times 0200h - 2 - ($ - $$)  db 0    ;fill rest of mbr
 
        dw 0AA55h       ;bootable signature