希望帮忙写个注释啊

assume cs:code,ds:data
data segment
  msg db "Welcome to Masm",0
data ends
code segment
start:
  mov ax,data
  mov ds,ax
  mov dh,12
  mov dl,(80-15-1)/2
  mov si,offset msg
  mov bl,02h
  call dispmsg
  mov ah,4ch
  int 21h
dispmsg proc near
  push ax
  push bx
  push cx
  push dx
  push si
  push di
  mov ax,0b800h
  mov es,ax
  mov al,dh
  mov cl,160
  mul cl
  mov di,ax
  mov al,dl
  mov cl,2
  mul cl
  add di,ax
 next: mov al,ds:[si]
  mov es:[di],al
  inc di
  inc si
  mov es:[di],bl
  inc di
  cmp byte ptr ds:[si],0
  jne next  
  pop di
  pop si
  pop dx
  pop cx
  pop bx
  pop ax
  ret
dispmsg endp
code ends
end start

自己的程序注释自己写。