16 bit crc in intel assembly

With the a86 assembler, didn't have a copy of tasm around

; 16 bit ccitt version, '123456789' => 0xe5cc
get_crc:
        push bx,si,cx
        mov ax,1d0fh
l1:     xor ah,[si]        
        inc si
        mov bx,8
l2:     shl ax,1
        jnc >l3
        xor ax,1021h
l3:     dec bx
        jnz l2
        loop l1
        pop cx,si,bx
        ret