NASM string spewer for DOS

dos.s

; vi:ft=nasm

cpu 8086
org 100h

section .text
	xor	bx,bx	; attrib
	mov	cx,1	; just one thanks

.again:	inc	bx	; next attrib
	and	bl,0x7F	; no flashing please
	mov	si,rulz

	mov	ah,0Bh	; check for keypress
	int	21h	; DOS
	test	al,al
	jnz .return

.loop:	lodsb 		; load next char
	test	al,al
	jz	.again

	mov	ah,09h	; write char with attrib
	int	10h	; BIOS
	mov	ah,0Eh	; write char and advance
	int	10h	; BIOS
	jmp	.loop

.return:
	ret

section .data
	rulz db 'seg rulz ok ',0